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PART 1: WHITE & RED LESIONS OF THE ORAL CAVITY

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1. Classification of Red and White Lesions of the Oral Cavity

• Leukoplakia (homogeneous, non-homogeneous - speckled, nodular, verrucous)
• Lichen planus
• Oral submucous fibrosis (OSMF)
• Candidiasis (pseudomembranous/hyperplastic forms)
• Hairy leukoplakia
• Traumatic keratosis
• White sponge nevus
• Fordyce spots

• Erythroplakia
• Atrophic/erosive lichen planus
• Erythematous candidiasis
• Median rhomboid glossitis

• Speckled leukoplakia (erythroleukoplakia) - highest malignant potential
• Candidal leukoplakia

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2. Why Do White Lesions Appear White?

1. Hyperkeratosis - thickening of the keratin layer increases opacity and reflects light
2. Acanthosis - thickening of the spinous layer
3. Parakeratosis - retention of nuclei in the keratin layer
4. Intracellular edema (spongiosis) - fluid between epithelial cells scatters light
5. The mucosal surface becomes opaque rather than translucent, so the underlying vascular (red) color is masked

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3. Leukoplakia - Aetiology, Clinical Features, and Treatment

• Tobacco (smoking, chewing, snuff) - most common
• Betel nut / areca nut chewing
• Alcohol
• Chronic irritation (sharp teeth, dentures)
• Candidal infection (candidal leukoplakia)
• Syphilis (syphilitic glossitis)
• UV radiation (lip)
• HPV (types 16, 18)
• Idiopathic (~20% cases)

• Most common in middle-aged and older men
• Sites: lip vermilion > buccal mucosa > mandibular gingiva > tongue > floor of mouth > hard palate
• Types:
  • Homogeneous: Flat, uniform white, smooth/finely wrinkled surface; lowest risk
  • Non-homogeneous:
    • Speckled (erythroleukoplakia): White patches on red background; highest risk
    • Nodular: Small rounded projections
    • Verrucous: Exophytic, warty surface
• Risk of malignant transformation: 0.13-17.5% overall; greatest in speckled/verrucous/floor-of-mouth lesions

• Eliminate risk factors (stop tobacco, alcohol)
• If benign/minimal dysplasia: periodic observation or elective excision
• Moderate dysplasia or worse: surgical excision or laser ablation
• Topical retinoids, beta-carotene for non-surgical candidates
• Regular follow-up every 3-6 months

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4. Oral Submucous Fibrosis (OSMF) - Investigations and Treatment

• Early: Burning sensation, erythema, vesicle formation
• Progressive: Pallor of mucosa (marble-like blanching), fibrous bands in buccal mucosa, palate, lips
• Trismus (limited mouth opening) - measured by interincisal distance
• Tongue mobility restricted
• Difficulty eating, swallowing, speech
• 7-30% risk of malignant transformation to SCC

• Atrophic epithelium overlying dense juxtaepithelial fibrous tissue (juxtaepithelial hyalinization)
• Reduction in blood vessels
• Inflammatory infiltrate

• Biopsy (confirmatory) - shows hyalinization and submucosal fibrosis
• MRI to assess extent of fibrosis
• Interincisal distance measurement (staging)

1. Eliminate causative agent (stop areca nut)
2. Medical:
   • Intralesional injections: triamcinolone (10 mg/mL) or dexamethasone ± hyaluronidase
   • Antioxidants: lycopene, spirulina
   • Pentoxifylline (antifibrotic)
   • Physiotherapy (mouth-opening exercises)
3. Surgical (advanced cases):
   • Fibrotomy with or without skin/mucosal grafting
   • Laser ablation of bands
   • Coronoidectomy if severe trismus

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5. Oral Lichen Planus - Types, Treatment

• Dense subepithelial band of chronic T-lymphocytes ("band-like" infiltrate)
• Civatte bodies (necrotic keratinocytes at basal layer)
• Saw-tooth rete pegs
• Vacuolar degeneration of basal cells
• DIF: Fibrinogen deposits in basement membrane zone

• Topical corticosteroids (first-line): Fluocinolone, clobetasol gel/paste
• Topical tacrolimus or cyclosporine (steroid-sparing)
• Intralesional steroid injections for refractory lesions
• Systemic corticosteroids for severe/widespread erosive disease
• Retinoids (systemic or topical)
• Regular monitoring (every 6 months) due to malignant transformation risk

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6. Oral Precancerous Conditions vs. Potentially Malignant Disorders

• Oral leukoplakia
• Oral erythroplakia
• Oral submucous fibrosis
• Oral lichen planus (erosive form)
• Actinic cheilitis
• Palatal changes in reverse smokers
• Discoid lupus erythematosus

• Erythroplakia (up to 50% dysplasia/malignancy at biopsy)
• Speckled leukoplakia

• Syphilitic glossitis
• Sideropenic dysphagia (Plummer-Vinson syndrome)
• Submucous fibrosis
• Discoid lupus erythematosus

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7. Oral Candidiasis - Classification, Predisposing Factors

1. Pseudomembranous (Thrush): Most common. White curd-like plaques that can be scraped off, leaving an erythematous base. Caused by Candida proliferating superficially.
2. Atrophic (Erythematous): Red, atrophic, smooth mucosa with loss of tongue papillae. Often seen in denture wearers or after antibiotic use.
3. Angular Cheilitis (Perlèche): Cracking, ulceration, and pseudomembrane at oral commissures. Often mixed with Staphylococcus.
4. Hyperplastic (Candidal leukoplakia): Rarest. Thick white plaque on buccal mucosa that CANNOT be scraped off. Resembles leukoplakia.

• Xerostomia (dry mouth)
• Denture wearing (especially at night)
• Topical corticosteroid inhalers
• Smoking
• Poor oral hygiene
• Broad-spectrum antibiotic use

• Immunosuppression (HIV/AIDS - CD4 < 200)
• Diabetes mellitus
• Malignancy and chemotherapy
• Corticosteroid therapy
• Malnutrition (iron, folate, zinc deficiency)
• Extreme ages (neonates, elderly)
• Organ transplant recipients

• Topical antifungals: Nystatin mouthwash/lozenges (first-line for mild cases)
• Systemic: Fluconazole 100-200 mg/day for 7-14 days (for severe/immunocompromised)
• In HIV: CD4 > 200 - topical nystatin; CD4 < 200 - systemic fluconazole
• Remove/treat predisposing factors

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8. Hairy Leukoplakia

• White, corrugated (hairy/shaggy), hyperkeratotic lesion on the lateral border of the tongue
• Caused by Epstein-Barr virus (EBV) replication in epithelial cells
• Strongly associated with HIV infection; its presence in a previously healthy person warrants HIV workup
• Asymptomatic; cannot be scraped off
• Diagnosis: EBV in biopsy (in-situ hybridization)
• Treatment: Acyclovir or valacyclovir; treat underlying HIV (antiretroviral therapy)

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9. Traumatic Keratosis

• White lesion caused by chronic friction/trauma (ill-fitting dentures, sharp tooth, cheek biting)
• Mimics leukoplakia but disappears when the irritant is removed
• Histology: hyperkeratosis without dysplasia
• Treatment: Remove the cause; lesion resolves in 2-4 weeks; biopsy if it persists

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10. Candidal Leukoplakia

• Variant of hyperplastic candidiasis
• White plaque on buccal mucosa or tongue that CANNOT be scraped off
• Histology: Candidal hyphae penetrating into the epithelium with dysplastic changes
• Considered a PMD (potentially malignant disorder)
• Treatment: Antifungal therapy (fluconazole); excision if dysplasia confirmed

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11. Antifungal Drugs and Uses

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PART 2: VESICULOBULLOUS DISORDERS

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12. Classification of Vesiculobullous Lesions of the Oral Cavity

• Primary herpetic gingivostomatitis (HSV-1)
• Herpes zoster (VZV)
• Hand-foot-mouth disease (Coxsackievirus A16)
• Herpangina (Coxsackievirus)

• Pemphigus vulgaris
• Mucous membrane (cicatricial) pemphigoid
• Bullous pemphigoid
• Linear IgA disease
• Dermatitis herpetiformis

• Erythema multiforme
• Stevens-Johnson syndrome (SJS)
• Toxic epidermal necrolysis (TEN)

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13. Primary Herpetic Gingivostomatitis - Clinical Features, Investigations, Management

• Primarily affects children and young adults (first exposure)
• Incubation: 5-7 days after contact with infected person
• Prodrome (up to 48 hours): Fever, malaise, irritability, submandibular lymphadenopathy, burning/tenderness of oral mucosa
• Vesicles form over entire oral mucosa (keratinized AND non-keratinized) - key distinguishing feature from recurrent herpes
• Vesicles rupture to form shallow, painful, discrete ulcers with erythematous halo
• Gingivitis is pathognomonic: Gingiva is erythematous, boggy, tender; free gingival margin discretely involved
• Can extend to oropharynx and perioral skin
• Duration: 7-14 days; self-limiting
• Viral shedding may continue for weeks after clinical resolution

• Usually clinical diagnosis
• Tzanck smear: multinucleated giant cells with eosinophilic intranuclear inclusions (Cowdry type A)
• Viral culture
• Serum antibody titers
• PCR for HSV DNA

• Primarily symptomatic and supportive
• Adequate fluid intake (prevent dehydration)
• Analgesics/antipyretics
• Topical anesthetics (lidocaine gel)
• Chlorhexidine rinses (prevent secondary bacterial infection)
• Acyclovir (400 mg 5x/day for 5-7 days) - for severe cases, immunocompromised, or very young children; reduces duration
• Rest and isolation

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14. Pemphigus Vulgaris - Clinical Features, Investigations, Management

• Usually fifth decade or beyond
• Oral lesions often precede skin lesions (in 50-70% of cases)
• Initial short-lived vesicles/bullae that rupture quickly
• Painful erosions and ulcers on gingival margins, buccal mucosa, labial mucosa, soft palate, lateral pharynx
• Nikolsky sign positive (lateral pressure dislodges epithelium)
• Laryngeal/esophageal involvement possible
• Paraneoplastic pemphigus: associated with lymphoproliferative malignancies

• Intraepithelial acantholysis (loss of intercellular connections)
• "Tombstone" effect: basal cells remain attached to basement membrane while suprabasal cells separate
• Tzanck cells (rounded acantholytic cells) in blister fluid

• Direct IF: IgG and C3 deposited in intercellular spaces between epithelial cells ("chicken-wire" pattern)
• Indirect IF: Circulating anti-Dsg antibody levels; correlates with disease severity

• Biopsy (H&E + DIF mandatory)
• ELISA for anti-Dsg3 antibodies
• Serum indirect IF

• Systemic corticosteroids (mainstay): High-dose prednisolone initially (1-2 mg/kg/day), then tapered
• Steroid-sparing immunosuppressants: Azathioprine, mycophenolate mofetil, cyclophosphamide, cyclosporine
• Rituximab (anti-CD20): Increasingly used as first-line in severe or refractory cases
• IV immunoglobulin (IVIG) for refractory disease
• Topical steroids for oral lesions
• Wound care, nutritional support

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15. Erythema Multiforme - Clinical Features and Treatment

• Infections: Recurrent HSV-1 (most common trigger for EM minor), EBV, hepatitis C, mycoplasma
• Drugs: Sulfonamides, anticonvulsants (carbamazepine, phenytoin), NSAIDs, allopurinol, nevirapine, antifungals, quinolones
• Photosensitivity

• Target/bull's-eye lesions on skin: Deep red center with concentric rings and pink urticarial rim - pathognomonic
• Symmetrical distribution
• Oral lesions: Aphthous-like ulcers, erosions, vesicles and bullae, covered with fibrinous plaque; extremely tender; can cause sialorrhea, dysarthria, inability to eat
• Sites in mouth: Lips (with hemorrhagic crusting), buccal mucosa, tongue, palate
• Spectrum:
  • EM minor (<10% BSA) - often post-HSV
  • SJS (10-30% BSA) - flu-like prodrome + hemorrhagic mucosal lesions
  • TEN (>30% BSA) - full-thickness epidermal necrosis, sepsis risk

• Clinical diagnosis; biopsy if uncertain
• Histopathology: Spongiosis, apoptotic basal cells, lymphohistiocytic infiltrate, vacuolar degeneration at basement membrane

• Mild EM: Symptomatic - analgesics, oral rinses, hydration; identify and eliminate trigger
• Moderate-severe / SJS/TEN:
  • Discontinue causative drug IMMEDIATELY
  • Hospitalization; supportive care (fluid/electrolyte replacement, wound care)
  • Transfer to burn unit for TEN
  • IV methylprednisolone (short course) or IV corticosteroids
  • IV immunoglobulin (IVIG) - may slow eruption
  • TNF-alpha inhibitors (etanercept), cyclosporine (3-5 mg/kg/day) under specialist care
  • Ophthalmologic evaluation
• Recurrent HSV-triggered EM: Long-term suppressive acyclovir 400 mg twice daily

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16. Stevens-Johnson Syndrome (SJS)

• Flu-like prodrome (fever, malaise, sore throat)
• Flat hemorrhagic lesions on mucosal membranes (oral, conjunctival, genital)
• Blistering on trunk and extremities
• Oral mucosa: painful, bloody erosions and pseudomembranes; difficulty eating/swallowing

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17. Herpes Zoster and Complications

• Unilateral vesicular eruption along dermatomal distribution of affected division
• Painful vesicles/ulcers restricted to one side of palate, tongue, buccal mucosa, lip
• Preceded by prodromal pain/burning in the affected area

• Postherpetic neuralgia - most common; severe burning pain persisting months after rash resolves
• Ramsay Hunt syndrome (VII nerve + ear) - facial palsy, vesicles in ear, taste loss
• Encephalitis, meningitis
• Ophthalmic zoster (V1) - keratitis, uveitis, blindness
• Secondary bacterial infection
• Disseminated zoster (immunocompromised)

• Antivirals (start within 72 hours): Acyclovir 800 mg 5x/day x 7-10 days; valacyclovir 1g TDS; famciclovir 500 mg TDS
• Analgesics, tricyclic antidepressants, gabapentin for postherpetic neuralgia
• Live attenuated vaccine (Zostavax) or recombinant vaccine (Shingrix) for prevention

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18. Difference Between Herpes Simplex and Herpangina

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19. Ectodermal Dysplasia

• Group of inherited disorders affecting tissues derived from ectoderm
• Classic triad: Hypohidrosis (absent/reduced sweat glands), Hypotrichosis (sparse hair), Hypodontia (absent/reduced teeth)
• X-linked hypohidrotic form (Christ-Siemens-Touraine syndrome) is most common
• Oral features: Oligodontia/anodontia, conical teeth, atrophic alveolar ridges
• Management: Prosthetic rehabilitation (dentures, implants), management of overheating (no sweating)

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20. Macule

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CONTINUING TOPICS FROM PAGE 27

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PART A: REMAINING VESICULOBULLOUS SIGNS/TERMS

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1. Ramsay Hunt Syndrome

1. Ipsilateral facial nerve palsy (lower motor neuron type - all branches)
2. Otalgia (severe ear pain)
3. Vesicular eruption in the external ear canal, auricle (pinna), and/or oral mucosa (soft palate, anterior 2/3 of tongue)

• Sensorineural hearing loss
• Tinnitus, vertigo (VIII nerve involvement)
• Loss of taste (anterior 2/3 of tongue - chorda tympani)
• Hyperacusis

• Acyclovir/valacyclovir (within 72 hours)
• Prednisolone (to reduce inflammation and nerve damage)
• Eye care (lubricating drops, patch) if eye closure is incomplete
• Prognosis: Worse than Bell's palsy; complete recovery in ~50%

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2. Patch Test

• Small concentrations of suspected allergens applied to the skin (usually upper back) in aluminum chambers
• Left in place for 48 hours
• Read at 48 hours and again at 72-96 hours
• Graded: -, +/-, +, ++, +++

• Used to identify allergens causing contact stomatitis or lichenoid reactions (e.g., to dental materials, preservatives, flavoring agents)
• Common oral allergens: mercury/amalgam, nickel, cinnamic aldehyde, propylene glycol

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3. Bulla [2M]

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4. Nikolsky's Sign

• Rub firmly with a finger across adjacent normal-appearing mucosa → epithelium wrinkles and slides off

• Pemphigus vulgaris (positive due to intraepithelial acantholysis)
• Toxic epidermal necrolysis (TEN)
• Stevens-Johnson syndrome (SJS)
• Staphylococcal scalded skin syndrome (SSSS)

• Pemphigoid (subepithelial split; epithelium attached to basement membrane is intact)
• Note: A modified Nikolsky's sign may be weakly positive at blister margins in pemphigoid

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5. Auspitz Sign

• Darier's disease
• Pemphigus foliaceus (rarely)

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PART B: ORAL ULCERATIVE DISEASES

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6. Classification of Oral Ulcers

• Acute (<3 weeks): Aphthous, traumatic, herpes, ANUG, drug-induced
• Chronic (>3 weeks): Malignancy, TB, syphilis, deep fungal, OSMF-related

• Mechanical (biting, sharp tooth, denture)
• Chemical (aspirin burns, phenol)
• Thermal (hot food/drinks)
• Radiation mucositis

• Viral: HSV (herpetic gingivostomatitis), herpangina, HZV
• Bacterial: ANUG (Vincent's infection), syphilitic chancre/gumma, TB
• Fungal: deep mycoses

• Recurrent Aphthous Stomatitis (RAS)
• Behcet's disease
• Crohn's disease, Ulcerative colitis
• Lichen planus (erosive)
• Pemphigus, Pemphigoid

• Squamous cell carcinoma
• Lymphoma, Kaposi's sarcoma

• Methotrexate, nicorandil, NSAIDs

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7. Recurrent Aphthous Stomatitis (RAS) / Aphthous Ulcers

• Local factors: Trauma, sodium lauryl sulfate in toothpaste
• Immunological: Cell-mediated cytotoxicity against oral epithelium; T-lymphocyte dysfunction
• Systemic associations:
  • Crohn's disease, Behcet's disease, celiac disease, ulcerative colitis
  • PFAPA syndrome (Periodic Fever, Aphthous ulcers, Pharyngitis, Adenitis)
  • Sweet syndrome
  • Nutritional deficiencies: iron, B12, folate, zinc
• Medications: NSAIDs, beta-blockers, potassium channel blockers, nicorandil
• Hormonal: Some women report premenstrual flares
• Stress - emotional and physical
• Genetic predisposition: 40% positive family history

• Round/oval, well-demarcated, shallow ulcer
• Yellow-grey fibrinous base
• Erythematous halo
• Extremely painful; worse with eating/drinking
• No fever (unless systemic association)
• No gingivitis (distinguishes from herpetic stomatitis)

• Usually clinical diagnosis
• Blood tests if recurrent/severe: CBC, iron, B12, folate, zinc, anti-TTG antibodies (celiac), HLA-B51 (Behcet's)
• Biopsy only if malignancy suspected

• Chlorhexidine 0.2% mouthwash (reduces secondary infection, reduces duration)
• Topical anesthetics: Benzocaine, lidocaine gel
• Topical corticosteroids: Triamcinolone acetonide 0.1% paste (Orabase), betamethasone sodium phosphate mouthwash
• Tetracycline mouth rinse (250 mg in 5 mL water, swish 2 min - reduces ulcer duration)

• Intralesional triamcinolone injections
• Systemic corticosteroids (prednisolone) for very severe cases
• Colchicine 0.5-1.5 mg/day (especially for Behcet's-associated)
• Dapsone, pentoxifylline
• Thalidomide (severe refractory - HIV-associated major aphthae)

• Identify and correct nutritional deficiencies
• Avoid trigger foods (acidic, spicy, SLS-containing toothpaste)
• Low-dose colchicine, dapsone

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8. ANUG (Acute Necrotizing Ulcerative Gingivitis) / Vincent's Disease

• Polymicrobial fusospirochetal infection:
  • Treponema vincentii (spirochetes)
  • Fusobacterium nucleatum (fusiform bacilli)
  • Prevotella intermedia, Bacteroides species
• These organisms are normally present in small numbers but become pathogenic when host defenses are compromised

• Poor oral hygiene (most important)
• Stress (exam period, war conditions - "trench mouth")
• Malnutrition
• Smoking
• Immunosuppression (HIV - ANUG is an AIDS-defining condition)
• Sleep deprivation

1. Pain - severe, throbbing gingival pain
2. Bleeding - spontaneous, profuse bleeding from gingival tissues
3. Characteristic punched-out, crater-like necrotic ulcers of interdental papillae - pathognomonic

• Pseudomembrane (grey slough) overlying the necrotic areas
• Fetor oris (extremely foul breath/halitosis) - very characteristic
• Metallic taste
• Low-grade fever, malaise, lymphadenopathy (in severe cases)
• If untreated: spreads to adjacent tissues → NOMA (cancrum oris) in malnourished/immunocompromised patients

1. Debridement - gentle supragingival scaling/debridement under local anesthesia; irrigate with hydrogen peroxide or saline
2. Antibiotics:
   • Metronidazole 400 mg TDS for 5-7 days (drug of choice - highly effective against anaerobes and spirochetes)
   • Alternatives: Amoxicillin, doxycycline, penicillin
3. Analgesics for pain
4. Chlorhexidine 0.2% mouthwash
5. Oral hygiene instruction
6. Nutritional support
7. Eliminate predisposing factors (stress, smoking)
8. HIV testing if recurrent/refractory

• Tissue destruction extending to ANUP (ulcerative periodontitis)
• NOMA (gangrenous stomatitis) - severe, disfiguring
• Bacteremia

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9. Desquamative Gingivitis

1. Mucous membrane pemphigoid (most common cause - ~70%)
2. Oral lichen planus (erosive/atrophic type)
3. Pemphigus vulgaris
4. Linear IgA disease
5. Epidermolysis bullosa acquisita

• Diffuse, fiery red, glazed, or eroded gingival mucosa
• Peeling/sloughing of the gingival epithelium
• Painful, bleeds easily on touch
• Affects attached gingiva (unlike gingivitis which primarily affects free margin)
• Positive Nikolsky's sign (in pemphigus)

• Biopsy + Direct Immunofluorescence (DIF) - mandatory to distinguish causes
  • Pemphigoid: Linear IgG/C3 at basement membrane zone
  • Pemphigus: IgG/C3 in intercellular spaces ("chicken wire")
  • Lichen planus: Fibrinogen at basement membrane zone

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PART C: ORAL AND MAXILLOFACIAL DISTURBANCES

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10. Myofascial Pain Dysfunction Syndrome (MPDS) / Temporomandibular Disorder

• Psychological/Psychogenic: Stress, anxiety, depression (major factor)
• Occlusal factors: Malocclusion, premature contacts, loss of vertical dimension
• Parafunctional habits: Bruxism (teeth grinding), clenching, nail biting, pen chewing
• Muscle hyperactivity secondary to stress → muscle fatigue and spasm
• Trauma to muscles of mastication

1. Unilateral, dull, aching pain in the masticatory muscles/preauricular area
2. Tenderness of one or more masticatory muscles on palpation
3. Clicking/popping sound in the TMJ
4. Limited and/or deflected jaw movement
5. Pain on opening and/or movement of the mandible

• Conventional X-rays (OPG, lateral oblique): Usually NORMAL - no bony changes
• In advanced/long-standing cases: condylar flattening, sclerosis, osteophytes (these indicate progression to true TMJ arthritis)
• CT/MRI for soft tissue evaluation (disc displacement)
• MRI (gold standard for disc position): Anterior disc displacement with/without reduction

1. Pain in the masticatory muscles or surrounding areas
2. Muscle tenderness
3. TMJ clicking or crepitation
4. Limited jaw opening (< 40 mm)
5. Absence of radiographic changes in the joint
6. Absence of other organic joint disease

• Patient education and reassurance
• Occlusal splint/bite guard - reduces bruxism, stabilizes occlusion
• Physiotherapy: Heat application, massage, jaw exercises, ultrasound
• Analgesics/NSAIDs: Ibuprofen, diclofenac
• Muscle relaxants: Diazepam, baclofen
• Psychological therapy: Cognitive behavioral therapy (CBT), biofeedback, stress management
• Soft diet

• Intra-articular corticosteroid injections
• Arthrocentesis (lavage of the TMJ)
• Arthroscopy
• Open joint surgery (condylectomy, disc repositioning) - last resort

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11. Trigeminal Neuralgia - Aetiology, Clinical Features, Differential Diagnosis, Management

• Classical (most common): Neurovascular compression - usually the superior cerebellar artery pulsating against the trigeminal nerve root at the pons → focal demyelination → ectopic impulses
• Secondary/Symptomatic: MS (multiple sclerosis), tumors (acoustic neuroma, meningioma), AVM, posterior fossa lesions
• Idiopathic: No identifiable cause

• Age: Usually >50 years; more common in women
• Unilateral (bilateral in <5% - suspect MS)
• Branches involved: V2 (maxillary) and/or V3 (mandibular) most common; V1 (ophthalmic) involvement rare
• Pain character: Electric shock-like, lancinating, stabbing, extremely severe, brief (seconds to 2 minutes)
• Trigger zones/factors: Touch, chewing, talking, swallowing, cold wind, washing face, brushing teeth
• Pain-free intervals between attacks (characteristic)
• No neurological deficit in classical form
• Trigger points: around nasolabial fold, lip, teeth, gingiva

• MRI brain (with FIESTA/CISS sequences) to identify neurovascular conflict or secondary causes
• MR angiography
• Blood tests to exclude MS

• Carbamazepine (drug of choice, 200-1200 mg/day) - sodium channel blocker; effective in 70%
• Oxcarbazepine (better tolerated than carbamazepine)
• Lamotrigine, gabapentin, pregabalin, baclofen
• Phenytoin (IV for acute attacks)

• Microvascular decompression (MVD) - gold standard surgical treatment; Teflon sponge placed between nerve and offending vessel; best long-term results
• Percutaneous rhizotomy: Balloon compression, glycerol injection, radiofrequency thermocoagulation (via foramen ovale)
• Gamma knife radiosurgery (stereotactic radiation)

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12. Oral Manifestations of AIDS/HIV

• Candidiasis: Pseudomembranous, erythematous, angular cheilitis - most common; indicator of immune status
• Hairy leukoplakia: White corrugated lesion on lateral tongue; EBV-related; not premalignant
• HIV-associated periodontal disease:
  • Linear gingival erythema (LGE) - red band at gingival margin
  • ANUG, ANUP (necrotizing ulcerative periodontitis)
• Kaposi's sarcoma: Most common oral malignancy in AIDS; red/purple/blue macule or nodule; most common on hard palate and gingiva
• Non-Hodgkin's lymphoma: Soft tissue swelling, may ulcerate

• Atypical ulceration (major aphthous-like)
• Thrombocytopenic purpura
• Necrotizing stomatitis
• Salivary gland disease (xerostomia, parotid enlargement - diffuse infiltrative lymphocytosis syndrome)

• Bacterial infections (tuberculosis, E. coli)
• Melanotic hyperpigmentation (drug-induced or adrenal involvement)

• CD4 > 500: LGE, mild candidiasis
• CD4 200-500: Moderate candidiasis, hairy leukoplakia
• CD4 < 200: Severe/esophageal candidiasis, Kaposi's sarcoma, lymphoma, ANUG/ANUP

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13. Oral Manifestations of Syphilis

• Hard chancre (painless ulcer) on lip or tongue - most common oral site
• Well-defined, indurated margins with rolled edges
• Regional lymphadenopathy (rubbery, non-tender)
• Heals in 3-8 weeks even without treatment

• Mucous patches - most characteristic oral lesion; grey-white, slightly raised oval plaques on buccal mucosa, palate, tongue; highly infectious
• Maculopapular rash (including palms and soles)
• Condylomata lata (moist warty lesions at commissures)
• Generalized lymphadenopathy, malaise

• Gumma - destructive granulomatous lesion; most commonly affects midline palate → palatal perforation; also tongue
• Interstitial glossitis (syphilitic glossitis): Atrophic, lobulated, fissured tongue; considered premalignant
• Luetic leukoplakia

• Hutchinson's incisors (notched, peg-shaped, narrower at biting edge)
• Mulberry molars (Moon's molars) - multiple irregular cusps on 1st permanent molars
• Interstitial keratitis
• Also: saber shins, saddle nose, sensorineural deafness

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14. Dental Fluorosis

• White opaque spots or streaks
• Brown discoloration (moderate-severe)
• Pitting and loss of enamel surface (severe)
• Affects multiple teeth (symmetrical)
• Teeth are more brittle

• Mild: Microabrasion, bleaching (tooth whitening)
• Moderate: Composite veneers, resin infiltration
• Severe: Porcelain veneers, crowns

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15. Burning Mouth Syndrome (BMS)

• Primary (idiopathic): Central or peripheral neuropathy; no identifiable cause
• Secondary (local): Candidiasis, geographic tongue, contact allergy, xerostomia, ill-fitting dentures
• Secondary (systemic): Nutritional deficiencies (B12, iron, zinc, folate), diabetes mellitus, hypothyroidism, hormonal changes (menopause), medications (ACE inhibitors), Sjogren's syndrome, psychological factors (anxiety, depression)

• Bilateral burning pain, constant or daily
• Typically worsens throughout the day, better in morning
• No mucosal changes visible on examination
• Burning may be relieved temporarily by eating/drinking (distinguishes from dental pain)
• Often associated with dysgeusia (altered taste) and xerostomia
• Predominantly affects postmenopausal women

• Treat any underlying cause
• Clonazepam (0.5 mg TDS - topical or systemic; most evidence)
• Alpha lipoic acid
• Tricyclic antidepressants (amitriptyline, nortriptyline)
• Gabapentin, pregabalin
• CBT (cognitive behavioral therapy) - good evidence
• Capsaicin (topical)

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16. Geographic Tongue (Benign Migratory Glossitis / Erythema Migrans)

• Well-demarcated, map-like, erythematous patches on dorsum and lateral margins of tongue
• Loss of filiform papillae in affected areas (red, smooth surface)
• Surrounded by slightly raised, white/yellow serpiginous border
• Lesions change in pattern, size, and location day to day ("migratory")
• Usually asymptomatic; occasional burning/sensitivity to spicy/acidic foods
• Often associated with fissured tongue

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17. Kolpik (Koplik's) Spots

• Tiny (1-3 mm), bluish-white/grey spots on an erythematous base
• Appear on the buccal mucosa opposite the lower molars bilaterally
• Described as "grains of salt on a red background" or "grains of sand"

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18. Lichenoid Reactions

• Drugs: Most common - NSAIDs, antihypertensives (methyldopa, beta-blockers, ACE inhibitors), antimalarials (chloroquine), gold salts, penicillamine, allopurinol, furosemide
• Dental materials: Amalgam restorations (mercury) - contact lichenoid reactions; lesions adjacent to amalgam fillings
• Graft-versus-host disease (GVHD)
• Hepatitis C virus (controversial)

• Contact lichenoid reactions are typically unilateral and adjacent to the causative material
• Often resolve on removing the causative agent
• Drug-induced: may have more erythematous/erosive component

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19. Causes for Oral Pigmentation

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20. Intrinsic Discoloration of Teeth

• Fluorosis - white spots/brown staining/pitting
• Tetracycline staining - yellow-grey-brown banding; permanent; affects teeth forming at time of drug intake (contraindicated in children <8 years and during pregnancy)
• Amelogenesis imperfecta - defective enamel formation; yellow/brown/pitted
• Dentinogenesis imperfecta - blue-grey/amber opalescent teeth; weak enamel
• Erythroblastosis fetalis - green/brown pigmentation from hemolytic products
• Congenital porphyria - red-brown pigmentation (erythrodontia)
• Hyperbilirubinemia - green/yellow discoloration

• Pulp necrosis - grey/dark discoloration
• Internal resorption - pink spot (pink tooth of Mummery)
• Pulp canal calcification - yellowing
• Caries - brown/black
• Blood breakdown products following trauma - grey

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21. Anodontia and Supernumerary Teeth

• True anodontia: Complete absence of all teeth (primary or permanent); extremely rare; associated with ectodermal dysplasia
• Oligodontia/Hypodontia: Congenital absence of 6 or more teeth (oligodontia) or fewer teeth (hypodontia); most common missing: 3rd molars > mandibular 2nd premolars > maxillary lateral incisors
• Causes: Ectodermal dysplasia (most common), Down syndrome, Rieger syndrome, genetic mutation (PAX9, MSX1)
• Treatment: Prosthetic replacement (dentures), dental implants, orthodontic space management

• Extra teeth beyond the normal dental formula
• Most common site: Maxillary anterior region - mesiodens (between central incisors) most common supernumerary
• Other types: Paramolar, distomolar (4th molar), parapremolar
• Associated conditions: Cleidocranial dysplasia, Gardner's syndrome, cleft lip/palate, Down syndrome
• Clinical problems: Crowding, delayed/prevented eruption, cyst formation, root resorption
• Treatment: Surgical extraction if causing problems; monitoring if asymptomatic

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22. Anti-retroviral Drugs and Antiviral Drugs [2M]

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23. Median Rhomboid Glossitis

• Previously thought to be developmental (persistence of tuberculum impar)
• Now accepted as a form of atrophic/erythematous oral candidiasis (C. albicans)
• Associated with smoking and denture wearing

• Smooth, flat or slightly raised, rhomboid/oval area on midline posterior tongue
• Erythematous (red), devoid of filiform papillae
• Usually asymptomatic; may burn slightly
• A "kissing lesion" on the palate may occur (palatal erythema from the infected tongue surface)

• Antifungal therapy (nystatin or fluconazole)
• Stop smoking
• Reassurance (benign)

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PART A: ORAL & MAXILLOFACIAL DISTURBANCES (CONTINUED)

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1. Atypical Facial Pain (Persistent Idiopathic Facial Pain)

• Poorly localized, diffuse, deep, aching or throbbing pain
• No clear trigger zones (unlike trigeminal neuralgia)
• Constant/continuous - no pain-free intervals
• Does not follow any anatomical nerve distribution
• Unilateral, usually maxillary area, may spread diffusely
• Strong psychological component - anxiety, depression, somatization
• More common in middle-aged women

• Tricyclic antidepressants (amitriptyline - drug of choice)
• CBT (cognitive behavioral therapy)
• Gabapentin, duloxetine
• Avoid unnecessary dental/surgical procedures

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2. Gemination and Fusion

• A single tooth bud attempts to divide incompletely → appears as one large tooth with a notched crown and a single root/root canal
• Counts as ONE tooth in the arch
• More common in primary dentition
• The tooth crown has a groove/notch dividing it partially
• Caused by invagination of a single tooth bud

• Union of two separate tooth buds by their dentin → forms one large tooth
• Results in a reduced tooth count in the arch (two teeth fuse to appear as one)
• May involve crown only or crown + root
• Usually has two root canals (or partially merged canals)
• Caused by physical pressure forcing two buds together during development
• Can be between normal teeth or between a normal tooth and a supernumerary

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3. Amalgam Tattoo

• Most common oral pigmented lesion seen clinically
• Aetiology: Accidental implantation of amalgam particles into the oral mucosa during dental procedures (extraction, placement, polishing)
• Clinical features:
  • Flat, grey/black/blue-grey macule
  • Well-defined or irregular margins
  • Most common sites: gingiva, alveolar mucosa, buccal mucosa
  • Asymptomatic; does not change over time
• Diagnosis:
  • Periapical radiograph may show radiopaque particles
  • Biopsy if uncertain (to rule out melanoma)
• Histology: Black/brown granules of metal along collagen fibers, blood vessels, and basement membrane; foreign body giant cell reaction possible
• Treatment: No treatment needed; reassurance; excision only for cosmetic reasons or diagnostic uncertainty

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4. Smoker's Melanosis

• Definition: Melanin pigmentation of the oral mucosa directly related to smoking
• Mechanism: Tobacco smoke stimulates melanocytes → increased melanin production and transfer to basal keratinocytes
• Sites: Anterior labial gingiva (most common), buccal mucosa, palate, lip
• Clinical features:
  • Diffuse, brown/dark macular pigmentation
  • Not pre-malignant
  • Correlates with the amount and duration of smoking
  • Regresses after smoking cessation (over months to years)
• Histology: Increased melanin in basal cell layer; no melanocytic proliferation (distinguishes from melanoma)
• Treatment: Smoking cessation; biopsy only if atypical features

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5. Taurodontism

• Definition: Anomaly of tooth morphology where the pulp chamber is enlarged apically at the expense of the roots, with the furcation displaced toward the apex.
• Literal meaning: "Bull-tooth" (Greek: tauros = bull)
• Aetiology: Failure of Hertwig's epithelial root sheath to invaginate at the proper horizontal level
• Classification:
  • Hypotaurodont (mild)
  • Mesotaurodont (moderate)
  • Hypertaurodont (severe - body of tooth almost fills entirely)
• Associated conditions: Klinefelter syndrome, Down syndrome, ectodermal dysplasia, Mohr syndrome, tricho-dento-osseous syndrome, amelogenesis imperfecta
• Radiographic features: Elongated pulp chamber, small/short roots, bifurcation displaced apically, "rectangular" tooth shape
• Clinical significance: Difficult endodontic treatment; no treatment if asymptomatic

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6. Oncovirus (Tumor Viruses)

• HPV 16/18: Oropharyngeal SCC (tonsil, base of tongue, soft palate); now surpassing tobacco as leading cause of oropharyngeal cancer in developed countries
• EBV: Hairy leukoplakia (in HIV), Burkitt's lymphoma of jaw
• HHV-8: Kaposi's sarcoma of oral cavity (AIDS)

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7. Define Pain

• Pain is always subjective and personal
• It is both a sensory AND emotional experience
• Cannot always be verified objectively

• Nociceptive: From actual tissue damage; somatic (sharp, localized) or visceral (dull, diffuse)
• Neuropathic: From nerve damage/dysfunction; burning, electric, shooting
• Nociplastic: From altered nociception without clear tissue damage (e.g., fibromyalgia, BMS)

• Acute: <3 months; protective function
• Chronic: >3 months; no biological purpose; significant psychosocial impact

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PART B: CYSTS AND TUMOURS OF THE OROFACIAL REGION

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8. Treatment for Oral Cancer (Squamous Cell Carcinoma)

• Primary treatment for most oral cancers
• Wide local excision with adequate margins (1 cm clear margin)
• Neck dissection: Radical, modified radical, selective (supraomohyoid) depending on node status
• Reconstructive surgery: Primary closure, local flaps (nasolabial, tongue flap), pedicled flaps (pectoralis major), free flaps (radial forearm, fibula free flap for mandible)

• Conventional external beam radiotherapy (EBRT)
• Intensity-modulated radiation therapy (IMRT) - spares salivary glands
• 60-66 Gy in 30-33 fractions (curative)
• Brachytherapy (for lip, tongue tumors)
• Post-operative RT for adverse features (positive margins, perineural invasion, lymphovascular invasion, multiple nodes)

• Cisplatin (most commonly used - radiosensitizer)
• Concurrent chemoradiation for locally advanced unresectable disease
• Palliative chemotherapy: Methotrexate, 5-FU, cetuximab (anti-EGFR)

• Cetuximab (anti-EGFR monoclonal antibody) - with radiation for cisplatin-ineligible patients

• Pembrolizumab, nivolumab (anti-PD-1) - for recurrent/metastatic disease

• Stage I/II: Surgery alone or RT alone
• Stage III/IV (resectable): Surgery + adjuvant RT ± chemo
• Stage IV (unresectable): Concurrent chemoradiation

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9. Lymphoma of the Oral Cavity

• Diffuse Large B-cell Lymphoma (DLBCL): Most common oral NHL
• Burkitt's Lymphoma: Associated with EBV; rapid growth; "starry sky" histology; jaw involvement (posterior mandible) in endemic (African) form; in AIDS patients
• Plasmablastic lymphoma: Strongly associated with HIV; affects jaw
• Extranodal Marginal Zone Lymphoma (MALT): Salivary glands

• Painless, rapidly enlarging soft tissue mass
• May be diffuse swelling or discrete nodule
• Sites: Posterior hard palate, gingiva, tongue, tonsil, jaw bone
• In AIDS: Often at unusual sites, aggressive behavior
• Systemic: Fever, night sweats, weight loss (B symptoms)

• Biopsy (incisional) + immunohistochemistry (essential)
• CT chest/abdomen/pelvis for staging
• Bone marrow biopsy, PET scan

• CHOP regimen (Cyclophosphamide, Hydroxydaunorubicin/Adriamycin, Vincristine/Oncovin, Prednisolone)
• R-CHOP (with Rituximab - anti-CD20) for B-cell lymphomas
• Radiation therapy for localized disease
• Burkitt's: High-dose chemotherapy (CODOX-M/IVAC)

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10. Fibroma of the Oral Cavity

• Smooth, sessile or pedunculated nodule
• Normal mucosal color (pink) or paler
• Firm consistency
• Usually <1 cm; well-defined
• Asymptomatic
• Most common site: Buccal mucosa along the bite line
• Also: Gingiva, labial mucosa, tongue, palate

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11. Osteosarcoma of the Jaw

• Occurs 1-2 decades later than long-bone osteosarcoma (mean age ~30 years vs. ~15 years)
• Better prognosis than long-bone osteosarcoma
• Metastasis less common/later

• Paget's disease of bone (malignant transformation)
• Prior irradiation
• Li-Fraumeni syndrome (p53 mutation)
• Retinoblastoma (Rb gene mutation)
• Fibrous dysplasia (rare)

• Painful swelling of the jaw
• Tooth mobility/loosening
• Paresthesia (inferior alveolar nerve involvement)
• Trismus (if masseter involved)
• Surface may be hard (sclerotic) or soft/fluctuant

• "Sunburst" appearance - radiating spicules of bone from the cortex (most characteristic)
• "Codman's triangle" - periosteal elevation at tumor margins
• Widened periodontal ligament space (earliest sign; "symmetric widening")
• May be osteolytic, osteoblastic (sclerotic), or mixed

• Malignant osteoblasts producing osteoid/bone directly
• Marked cellular pleomorphism and mitoses

• Wide surgical resection with clear margins (primary treatment)
• Adjuvant/neoadjuvant chemotherapy (for long-bone osteosarcoma; less established for jaw)
• Radiation: Jaw osteosarcoma is relatively radioresistant
• Better 5-year survival for jaw (~60-80%) vs. long bone (~60%)

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12. Periapical Cyst (Radicular Cyst / Dental Cyst)

1. Dental caries → pulp necrosis → periapical inflammation
2. Stimulation of rests of Malassez (epithelial remnants in PDL)
3. Epithelial proliferation → cyst lining formation
4. Cyst enlargement by osmotic pressure and enzymatic activity

• Associated with a non-vital tooth
• Usually asymptomatic unless infected
• If infected: pain, swelling, fluctuance
• Expansion of cortical plates (buccal > lingual)
• Negative vitality test on associated tooth

• Well-defined, round/ovoid, periapical radiolucency at root apex
• Continuous with the lamina dura (which is lost)
• Corticated (sclerotic) border (white line) - indicates slow-growing, benign lesion
• Usually <2 cm (large cysts: radicular cyst vs. residual cyst)

• Arcaded/anastomosing non-keratinized stratified squamous epithelium lining
• Fibrous connective tissue wall with chronic inflammatory cells
• Cholesterol clefts, Rushton bodies (hyaline bodies - pathognomonic)
• Hemosiderin deposits

• Root canal treatment (endodontic therapy) → small cysts may resolve
• Enucleation (surgical removal of entire cyst lining) for larger cysts
• Apicoectomy (surgical removal of root apex) if endodontic treatment fails
• Marsupialisation for large cysts
• Extraction of the tooth + cyst enucleation

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13. Odontogenic Keratocyst (OKC) / Keratocystic Odontogenic Tumor (KCOT)

• WHO 2005: renamed to "Keratocystic Odontogenic Tumor" (KCOT) due to aggressive nature
• WHO 2017: reverted back to "Odontogenic Keratocyst" (OKC)
• Associated with PTCH1 gene mutation (tumor suppressor)
• Gorlin-Goltz syndrome (Nevoid BCC syndrome): Multiple OKCs + multiple basal cell carcinomas of skin + skeletal anomalies

• Most common in posterior mandible (angle and ramus region)
• Peak incidence: 2nd-3rd decade
• Often asymptomatic; discovered incidentally on X-ray
• Can grow to large size with minimal cortical expansion (grows anteroposteriorly in the medullary cavity)
• May displace teeth without resorption of roots (unlike ameloblastoma which resorbs)

• Well-defined unilocular or multilocular radiolucency
• Scalloped margins (characteristic)
• Corticated border
• May surround unerupted teeth (resembles dentigerous cyst)
• Associated with the crown of impacted tooth in ~30%

• Thin, uniform, parakeratinized stratified squamous epithelium (5-8 cell layers)
• Flat epithelial-connective tissue interface (no rete ridges)
• Palisaded, hyperchromatic, polarized basal cells ("tombstone" or "picket-fence" basal layer) - most characteristic feature
• Corrugated parakeratinized surface
• Satellite cysts, epithelial islands in wall

• Enucleation + Carnoy's solution (chemical fixative to destroy satellite cysts)
• Enucleation + peripheral ostectomy
• Marsupialisation (for large cysts; reduces size before enucleation)
• Resection for recurrent/aggressive cases
• High recurrence rate: 25-60% due to thin friable lining and satellite cysts

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14. Pyogenic Granuloma - Aetiology and Clinical Features

• Local irritation/trauma (most important): plaque, calculus, foreign bodies, trauma
• Hormonal changes: Very common during pregnancy (called "pregnancy tumor" or granuloma gravidarum) due to progesterone effects on vascularity; affects gingiva in ~1% of pregnant women
• Medications: Calcium channel blockers, cyclosporine, phenytoin (can cause similar gingival overgrowth)
• Poor oral hygiene

• Bright red to deep red/purple, smooth or lobulated, soft, pedunculated or sessile mass
• Highly vascular - bleeds profusely even with slight trauma
• Often ulcerated on the surface
• Rapid growth - may appear alarming (can mimic malignancy)
• Size: few mm to several cm
• Most common site: Gingiva (especially interdental papilla); also lips, tongue, buccal mucosa
• May arise on the gingiva at the site of calculus or foreign body
• Usually painless

• Highly vascular proliferation resembling granulation tissue
• Numerous endothelial-lined vessels
• Mixed inflammatory infiltrate
• Ulcerated surface covered with fibrinopurulent membrane

• Surgical excision with removal of underlying irritant
• Scaling and root planing
• Pregnancy tumors often regress after delivery; excise if persistent or large
• Recurrence ~16% if underlying cause not removed

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15. Aetiology and Risk Factors for Oral Cancer [2M]

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16. Cementoma (Cemento-ossifying Fibroma / Periapical Cemental Dysplasia)

1. Periapical cemental dysplasia (Periapical cemento-osseous dysplasia): Most common; affects anterior mandible in Black women; multiple lesions; VITAL teeth (key point - distinguishes from periapical cyst)
2. Cemento-ossifying fibroma: True neoplasm; solitary; posterior mandible; can be large
3. Florid cemento-osseous dysplasia: Multiple quadrants; Black women

1. Stage 1 (Osteolytic): Radiolucent (may mimic periapical cyst - but tooth is VITAL)
2. Stage 2 (Mixed): Mixed radiolucent/radiopaque
3. Stage 3 (Mature/Calcific): Dense radiopaque mass surrounded by radiolucent rim

• Periapical cemental dysplasia: No treatment needed; reassurance; observe
• Cemento-ossifying fibroma: Surgical enucleation (low recurrence)

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17. Gorlin-Goltz Syndrome (Nevoid Basal Cell Carcinoma Syndrome)

1. Multiple odontogenic keratocysts (OKCs) - appear early (1st/2nd decade); multiple; jaw cysts are often the first presentation
2. Multiple basal cell carcinomas (BCCs) of skin - appear in 2nd decade; arise without UV exposure; can number in the hundreds
3. Skeletal anomalies: Bifid ribs, kyphoscoliosis, bridged sella turcica, calcified falx cerebri (pathognomonic)
4. Ectopic calcification: Lamellar calcification of falx cerebri (seen on skull X-ray)
5. Facial features: Frontal bossing, hypertelorism, mandibular prognathism, broad nasal root

• OKCs: Enucleation ± Carnoy's solution; high recurrence; long-term follow-up
• BCCs: Vismodegib (Hedgehog pathway inhibitor), surgery, photodynamic therapy; AVOID radiation (induces more BCCs)
• Regular surveillance

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18. Papilloma of the Oral Cavity

• Cauliflower-like, warty/verrucous, exophytic mass
• White or pink color
• Pedunculated (narrow stalk)
• Multiple small finger-like projections ("papillary fronds")
• Size: Usually <1 cm
• Sites: Soft palate, uvula, tongue, frenulum, lip - any mucosal surface
• Asymptomatic
• Solitary (multiple lesions suggest HPV-related conditions - condyloma, multifocal epithelial hyperplasia)

• Finger-like projections of stratified squamous epithelium
• Central fibrovascular core
• Koilocytes (perinuclear halo) - indicate HPV infection
• No dysplasia

• Surgical excision (scalpel or laser)
• Low recurrence rate
• No malignant potential (HPV 6/11 are low-risk)

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19. Ameloblastoma

1. Conventional ameloblastoma (most common; locally invasive; mainly posterior mandible)
2. Unicystic ameloblastoma (less aggressive; young patients; associated with impacted teeth)
3. Extraosseous/peripheral ameloblastoma (on the gingiva; most benign behavior)
4. Metastasizing ameloblastoma (histologically benign but metastasizes)

• Age: Any age; peak 3rd-4th decade
• Site: Posterior mandible (angle/ramus/body) 80%; maxilla less common
• Slow-growing, painless, progressive bony swelling
• Buccal and lingual cortical plate expansion
• Late stages: Facial asymmetry, tooth mobility/loosening, root resorption
• Recurrence after conservative treatment is common

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20. Radiographic Features of Ameloblastoma

• Multilocular "soap bubble" or "honeycomb" appearance (most characteristic) - irregular, scalloped locules of different sizes
• Unilocular in some cases (especially early or unicystic type)
• Well-defined radiolucency with clear margins
• Scalloped or scalloped margins between trabeculae
• Cortical expansion - buccal and lingual plates thinned and expanded
• Root resorption - characteristic; distinguishes from OKC (which displaces without resorbing)
• May be associated with unerupted tooth (dentigerous relationship)
• Located in posterior mandible, ramus area
• Thinning/perforation of cortex in large tumors

• Unilocular well-defined radiolucency around crown of unerupted tooth (mimics dentigerous cyst)

• Resection with adequate bony margin (1-1.5 cm of normal bone) - gold standard; low recurrence
• Conservative enucleation/curettage for unicystic type - higher recurrence (25-90%)
• Peripheral ameloblastoma: simple excision
• Reconstruction with bone grafts/implants

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21. TNM Classification of Oral Cancer

• M0: No distant metastasis
• M1: Distant metastasis present

• Stage I: T1N0M0
• Stage II: T2N0M0
• Stage III: T3N0M0 or T1-3 N1M0
• Stage IVA: T4a or N2
• Stage IVB: T4b or N3
• Stage IVC: M1

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SALIVARY GLAND DISORDERS

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1. Pleomorphic Adenoma (Benign Mixed Tumor)

• Most common salivary gland neoplasm overall
• Peak age: 4th-6th decade; slight female predominance
• Most common site: Parotid gland (80%) - superficial lobe, lower pole
• Also: submandibular gland, minor salivary glands (hard palate most common site for minor gland PA)

• Arises from myoepithelial cells and ductal epithelial cells
• Prior radiation exposure is a risk factor
• Associated with PLAG1 or HMGA2 gene rearrangements

• Slow-growing, painless, firm, mobile mass
• Well-defined, smooth or bosselated (lobulated) surface
• No facial nerve involvement (distinguishes from malignancy)
• Rubbery consistency (due to chondromyxoid stroma)
• If left untreated: can grow very large
• Malignant transformation occurs in ~3-5% (carcinoma ex pleomorphic adenoma) - suggested by rapid growth, pain, fixity, facial nerve palsy

• Biphasic tumor: Epithelial component + mesenchymal (stromal) component
• Epithelial cells: Form ducts, acini, sheets, cords; mixed ductal and myoepithelial cells
• Stromal component (mesenchyme-like): Chondromyxoid (cartilaginous) stroma, myxoid areas, hyalinized collagen - the KEY feature that differentiates PA from other tumors
• No true capsule - thin, incomplete fibrous pseudocapsule with tumor projections (pseudopods) through it → reason for recurrence if enucleated

• Ultrasound: Well-defined, hypoechoic, lobulated mass; heterogeneous in large lesions
• CT: Well-defined hypodense mass with mild enhancement
• MRI: Low T1, high T2 signal; "light bulb bright" on T2 - characteristic

• Fibrillary chondromyxoid material (magenta stained)
• Plasmacytoid/epithelioid myoepithelial cells
• Ductal epithelial cells

• Superficial parotidectomy (for parotid PA in superficial lobe) - with preservation of the facial nerve
• Total parotidectomy if in deep lobe
• DO NOT enucleate - high recurrence (30-40%) due to pseudopod extensions through capsule
• Superficial parotidectomy recurrence rate: ~2-4%
• Minor gland PA: Wide local excision
• Submandibular: Excision of the entire gland

• Facial nerve injury (temporary or permanent palsy)
• Frey's syndrome (auriculotemporal nerve syndrome): gustatory sweating - sweating and flushing over cheek/preauricular area when eating; treated with anticholinergics or Botulinum toxin
• Scar, salivary fistula, first bite syndrome

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2. Sjogren's Syndrome

• Primary Sjogren's: Occurs alone without another connective tissue disease
• Secondary Sjogren's: Occurs in association with another autoimmune disease (most commonly rheumatoid arthritis; also SLE, systemic sclerosis, polymyositis)

• Predominantly middle-aged women (F:M = 9:1)
• Second most common autoimmune rheumatic disease after RA

• Genetic predisposition (HLA-DR3, HLA-DR2) + environmental trigger (viral?)
• CD4+ T-cell and B-cell lymphocytic infiltration of exocrine glands
• Autoantibodies: Anti-Ro/SSA and anti-La/SSB (most specific)
• Lymphocytic infiltration → acinar destruction → reduced secretion

• Dry mouth (xerostomia) - most common complaint
• Difficulty chewing, swallowing, speaking
• Burning mouth, altered taste
• Bilateral parotid gland enlargement (firm, non-tender)
• Oral mucosa: dry, red, atrophic, glazed
• Fissured/lobulated tongue (lobulated "crocodile tongue")
• Accelerated dental caries (loss of protective saliva)
• Candidiasis (secondary to xerostomia)

• Dry eyes, foreign body sensation ("sand in the eyes")
• Photophobia, blurred vision
• Rose Bengal staining shows punctate corneal erosions
• Schirmer's test: <5 mm wetting in 5 minutes = positive

• Arthralgia/arthritis (non-erosive)
• Cutaneous: purpura, Raynaud's phenomenon
• Pulmonary: interstitial lung disease
• Renal tubular acidosis
• Peripheral neuropathy
• Increased risk of Non-Hodgkin's B-cell lymphoma (40x increased risk) - mucosa-associated lymphoid tissue (MALT) lymphoma of salivary glands

• Schirmer's test: Measures tear production; <5 mm/5 min = positive
• Rose Bengal/lissamine green staining: Corneal damage
• Salivary flow rate: Unstimulated whole saliva <0.1 mL/min = xerostomia
• Minor salivary gland biopsy (labial gland biopsy - lower lip): Focus score ≥1 (≥1 lymphocytic focus of ≥50 cells per 4 mm²) - most specific diagnostic test
• Serology: Anti-Ro/SSA (+ve in ~70%), Anti-La/SSB (+ve in ~50%), ANA, RF, elevated ESR/CRP
• Sialography: "Snowstorm" or "cherry blossom" appearance (punctate/globular sialectasis)
• Salivary scintigraphy: Reduced uptake and secretion
• Ultrasound parotid: Heterogeneous echotexture with hypoechoic areas

• Lip biopsy with focal lymphocytic sialadenitis (score 3)
• Anti-SSA/Ro positive (score 3)
• Ocular staining score ≥5 (score 1)
• Schirmer's ≤5 mm/5 min (score 1)
• Unstimulated salivary flow ≤0.1 mL/min (score 1)

• Artificial tears (hydroxymethylcellulose drops, cyclosporine eye drops)
• Artificial saliva (carboxymethylcellulose sprays, gels)
• Salivary stimulants: Pilocarpine (muscarinic agonist, 5 mg TDS) - increases salivary and lacrimal flow; contraindicated in asthma, glaucoma
• Cevimeline (another muscarinic agonist)
• Sugar-free chewing gum, lozenges
• Fluoride supplements/applications (prevent dental caries)
• Antifungals for candidiasis
• Moisture-retaining spectacle shields for eyes

• Hydroxychloroquine (antimalarial) - for systemic manifestations, arthralgia, fatigue
• NSAIDs for arthralgia
• Corticosteroids for severe systemic manifestations
• Rituximab (anti-CD20) for severe systemic disease or lymphoma

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3. Sialography

• Sialolithiasis (salivary stones) - localize calculi
• Chronic sialadenitis - assess ductal changes
• Sjogren's syndrome - punctate sialectasis
• Salivary gland strictures
• Salivary gland tumors (indirectly - shows ductal displacement)
• Sialodochitis (ductal inflammation)

• Acute sialadenitis (injection may worsen infection, cause rupture)
• Allergy to iodinated contrast media
• Thyroid disease (iodine-containing contrast interferes with thyroid function tests)

1. Identify the duct orifice (Stensen's duct for parotid - opposite upper 2nd molar; Wharton's duct for submandibular - floor of mouth lateral to frenulum)
2. Dilate the orifice with lacrimal dilators
3. Inject water-soluble iodinated contrast medium (e.g., Urografin) via a blunt cannula
4. Take radiographs in anteroposterior, lateral, and oblique views
5. May take films before injection, during filling (parenchymal phase), and after secretory stimulation (emptying phase)

• Main duct is smooth, tapering from hilum to orifice
• Arborizing secondary and tertiary ducts - "tree in winter" or "herring bone" appearance

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4. Sialadenitis

A. Acute Suppurative Sialadenitis

• Bacterial: Most commonly Staphylococcus aureus (most common in acute parotitis); also Streptococcus viridans, Haemophilus influenzae
• Risk factors: Dehydration (most important - reduced salivary flow allows retrograde bacterial migration), debilitated patients, post-operative (elderly surgical patients), xerostomia, poor oral hygiene, duct obstruction (calculus)

• Parotid gland most commonly affected
• Sudden onset painful swelling of the gland
• Tender, firm/indurated enlargement
• Erythema of overlying skin
• Trismus
• Fever, malaise
• Pus expressible from the duct orifice (Stensen's duct) on massaging - pathognomonic
• Facial nerve intact (differentiates from malignancy)

• IV antibiotics (anti-staphylococcal: flucloxacillin, amoxicillin-clavulanate, clindamycin)
• Adequate hydration (most important)
• Analgesics
• Warm compresses, massage
• Oral hygiene
• Incision and drainage if abscess forms

B. Chronic Recurrent Parotitis

• Recurrent episodes of parotid swelling and pain
• Associated with ductal ectasia and sialectasis
• Sialography: "Sausage link" main duct, punctate/globular peripheral sialectasis
• Treatment: Sialography itself (dilation + contrast acts therapeutically), parotidectomy for severe cases

C. Viral Sialadenitis (Mumps)

• Paramyxovirus (Mumps virus)
• Bilateral parotid swelling, fever
• Complications: Orchitis (leading to infertility), meningitis, encephalitis, pancreatitis, oophoritis
• Treatment: Supportive; MMR vaccine for prevention

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5. Causes of Sialorrhoea [2M]

• Parkinson's disease (most common cause in adults) - due to impaired swallowing reflex and reduced oral motor control, NOT true hypersecretion
• Cerebral palsy (children - most common cause in children)
• Motor neuron disease/ALS
• Stroke, brain tumors
• Bulbar/pseudobulbar palsy
• Multiple sclerosis
• Down syndrome
• Intellectual disability

• Pilocarpine (cholinergic drug)
• Clozapine (antipsychotic - most common drug cause; due to M4 agonism)
• Risperidone, lithium
• Physostigmine, organophosphates
• Bethanechol

• Painful oral lesions (ulcers, stomatitis) - reduces swallowing
• Teething in infants
• Ill-fitting dentures
• Peritonsillar abscess

• Nausea, acid reflux (GERD)
• Esophageal obstruction

• Rabies (most dramatic hypersalivation)
• Encephalitis

• Infants under 18 months (normal - weak oral motor control)
• Pregnancy (first trimester - ptyalism gravidarum)
• Hunger/anticipation of food

• Treat underlying cause
• Anticholinergic drugs: Glycopyrrolate (does not cross BBB), hyoscine (scopolamine) patch, atropine drops sublingually
• Botulinum toxin injection into parotid and/or submandibular glands (highly effective; lasts 3-6 months)
• Surgery: Duct ligation or rerouting, submandibular gland excision, parotid duct rerouting
• Speech therapy, behavioral interventions, biofeedback

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6. Management of Xerostomia (Dry Mouth)

• Medications (most common cause): Anticholinergics, antihistamines, antidepressants, diuretics, antihypertensives, opioids - over 400 medications cause xerostomia
• Radiation to head and neck (most severe, irreversible - damages acinar cells)
• Sjogren's syndrome
• Dehydration
• Diabetes mellitus
• HIV/AIDS
• Anxiety, depression

• Frequent sips of water throughout the day
• Sugar-free chewing gum or lozenges (stimulate reflex salivation)
• Humidifier at night
• Avoid: alcohol-containing mouthwashes, caffeine, tobacco, carbonated drinks
• Rigorous oral hygiene + fluoride applications (high-caries risk)
• Regular dental check-ups

• Carboxymethylcellulose-based sprays/gels (e.g., Biotene, Oralbalance)
• Mucin-based substitutes (more similar to natural saliva)
• Provide lubrication but no enzymatic/antimicrobial protection

• Pilocarpine (5 mg TDS, up to 10 mg TDS) - muscarinic agonist; most evidence; SE: sweating, flushing, urinary frequency, bradycardia; CI: asthma, narrow-angle glaucoma
• Cevimeline (30 mg TDS) - more selective M3/M1 agonist; fewer SE; longer duration
• Sugar-free citric acid lozenges (stimulate mechanically and chemically)

• Candidiasis: Nystatin, fluconazole
• Dental caries: Fluoride varnish, remineralizing toothpaste (high-fluoride), pit and fissure sealants
• Mucositis from radiation: Amifostine (radioprotector given before RT to preserve salivary glands)

• IMRT (Intensity-Modulated Radiation Therapy): Spares parotid glands; gold standard for prevention
• Amifostine: Radioprotective agent given before each radiation session
• Submandibular gland transfer: Surgically move submandibular gland out of radiation field before RT
• Acupuncture: Some evidence for benefit

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7. Sialolithiasis (Salivary Duct Calculus / Salivary Stone Disease)

• Most common salivary gland disease
• Peak incidence: 4th-6th decade; male predominance

• Submandibular gland and Wharton's duct: 80-92% (most common)
  • Reasons: Wharton's duct is long, tortuous, and travels upward against gravity; submandibular saliva is more viscous, alkaline, and rich in mucin; higher calcium and phosphate content
• Parotid gland and Stensen's duct: 5-10%
• Sublingual gland: <1%

• Obstructive symptoms: Recurrent painful swelling of the affected gland, especially during meals ("mealtime syndrome") - salivary flow is stimulated by eating but blocked by the stone
• Swelling subsides between meals
• Submandibular: Floor of mouth swelling/tenderness; stone may be palpable bimanually
• Parotid: Preauricular/cheek swelling
• If infected (secondary sialadenitis): Fever, tenderness, pus from duct
• Stone may be visible or palpable in the floor of the mouth

• Plain X-ray (Lower occlusal view / panoramic OPG): 80-90% of submandibular stones are radiopaque; 40-60% of parotid stones are radiopaque
• Ultrasound: Excellent for locating stones; shows hyperechoic focus with acoustic shadowing; duct dilatation proximal to stone
• CT (non-contrast): Most sensitive; detects all calcified stones
• MR Sialography: Non-invasive; shows ductal anatomy and filling defects
• Sialography (contrast): Filling defect at stone site; ductal dilatation proximal to stone; use with caution (never in acute infection)
• Sialoendoscopy: Diagnostic AND therapeutic (direct visualization of duct, stone removal)

• Increased hydration, salivary stimulants (citrus, chewing gum), warm massage
• Many small stones pass spontaneously

• Sialoendoscopy: Endoscopic retrieval with baskets/forceps; for stones <5 mm in Wharton's or Stensen's duct; now first-line approach
• Extracorporeal Shock Wave Lithotripsy (ESWL): Fragmentation of stones using shock waves; best for parotid stones 5-12 mm; multiple sessions
• Intraoral stone removal (ductotomy): For stones palpable/visible in distal Wharton's duct; incise duct floor over stone and retrieve under LA; marsupialize duct
• Combined sialoendoscopy + lithotripsy

• Submandibular gland excision: For large/proximal stones, recurrent infections, failed minimally invasive treatment; risk: damage to lingual nerve, marginal mandibular nerve, hypoglossal nerve
• Parotidectomy: Rarely needed for parotid stones

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8. Sialolith

• Inorganic: Calcium phosphate (hydroxyapatite - ~75%), calcium carbonate, magnesium phosphate
• Organic core/nidus: Bacterial debris, mucoproteins, desquamated epithelial cells, foreign bodies

• Round, oval, or irregular shaped
• Yellow/white
• Hard consistency
• Size: from <1 mm to several centimeters (rare giant sialolith)
• Surface: smooth or rough/spiculated

• Laminated, concentric rings of calcified material around a central nidus
• Alternating light and dark mineralized layers
• Bacterial colonies and organic debris at the center

1. Nidus formation: Bacteria, desquamated cells, or foreign particles aggregate in the duct
2. Calcium phosphate precipitation around the nidus (salivary supersaturation)
3. Progressive layered calcification
4. Stone enlarges with time

• Most common in Wharton's duct (submandibular) - 80-92%
• Submandibular saliva is thicker, more mucoid, higher calcium - predisposed
• Single stones most common; multiple stones possible
• Rarely, stones form in the parotid parenchyma (intraglandular sialolith)
• Can be a source of chronic recurrent sialadenitis if not treated

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PART A: MISCELLANEOUS ORAL MEDICINE TOPICS

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1. Angular Cheilitis

• Microbial: Candida albicans (most common, ~70%); Staphylococcus aureus; mixed infection
• Nutritional deficiencies: Iron deficiency, B12, riboflavin (B2), folate, zinc
• Mechanical: Loss of vertical dimension (edentulous patients, worn dentures) → lip folding/maceration
• Immunosuppression: HIV, diabetes mellitus
• Salivary pooling at commissures in elderly or mouth-breathers

• Erythema, maceration, superficial fissures/cracks at one or both corners
• Crusting, scaling, ulceration in severe cases
• Pain/burning on mouth opening

• Antifungal cream: Miconazole or nystatin (for Candida)
• Combined antifungal + antibacterial: Miconazole (covers both Candida and Staph)
• Correct nutritional deficiencies
• Replace or reline dentures to restore vertical dimension
• Low-potency topical steroid + antifungal combination

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2. Stomatitis Medicamentosa

• Penicillin, sulfonamides, barbiturates, NSAIDs, phenytoin, gold salts, mercury compounds

• Diffuse erythema, edema, vesiculation, ulceration of the oral mucosa
• May resemble severe aphthous stomatitis or erythema multiforme
• Associated systemic features: skin rash, urticaria, fever
• Burning/pain

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3. Gardner's Syndrome

• Multiple osteomas of the jaw (mandible most common)
• Supernumerary teeth, compound odontomas
• Impacted/unerupted teeth (multiple)
• Hypercementosis
• Early detection of jaw osteomas on OPG may precede colorectal polyps by years

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4. Corticosteroids in Oral Medicine

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5. Topical Corticosteroids

• Use minimum effective potency
• Do not use under occlusion for prolonged periods
• Dry the lesion before applying paste for better adhesion
• Clobetasol propionate (0.05% gel) - first-line for erosive OLP, pemphigoid

• Secondary oral candidiasis (most common)
• Adrenal suppression (with prolonged high-potency use)
• Delayed healing

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6. Immunofluorescence Test in Oral Medicine

Direct Immunofluorescence (DIF):

• Performed on a fresh tissue biopsy (perilesional tissue - normal-appearing mucosa adjacent to lesion)
• Frozen sections processed; incubated with fluorescent-labeled antibodies
• Used to identify immune deposits in tissue

Indirect Immunofluorescence (IIF):

• Performed on patient serum (not tissue)
• Patient serum applied to substrate (monkey esophagus, guinea pig esophagus)
• Detects circulating antibodies
• Pemphigus: IIF titer correlates with disease activity

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7. Antibiotics in Oral Medicine / Antibiotics in Dentistry

• Use only when there is spreading infection, systemic involvement, or immunocompromise
• Not indicated for localized abscesses (drainage is the treatment)
• Follow ALARA principle - use narrowest spectrum for shortest effective duration

• Amoxicillin 2 g orally 30-60 min before procedure
• If allergic: Clindamycin 600 mg (UK guideline) OR Azithromycin/Clarithromycin 500 mg
• Indications: High-risk cardiac conditions (prosthetic valves, previous IE, certain congenital heart disease) undergoing high-risk dental procedures (extraction, periodontal work, root canal treatment beyond apex)

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8. Clindamycin

• Gram-positive cocci: Staphylococcus, Streptococcus (including MRSA strains)
• Anaerobes: Bacteroides, Fusobacterium, Peptostreptococcus - excellent anaerobic coverage
• NOT effective against Gram-negatives (E. coli, Pseudomonas)

• Alternative to penicillin in penicillin-allergic patients for dental infections
• Antibiotic prophylaxis for endocarditis (600 mg, single dose)
• Osteomyelitis of the jaw (excellent bone penetration)
• Severe polymicrobial oral infections

• Pseudomembranous colitis (caused by C. difficile overgrowth - most important side effect); most likely antibiotic to cause C. diff colitis
• Diarrhea, nausea
• Skin rash

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9. Topical Analgesics

• Choline salicylate gel (Bonjela): Anti-inflammatory + mild anesthetic
• Benzydamine (Difflam): NSAID-type; rinse or spray; reduces post-radiation mucositis pain
• Carbenoxolone gel: Anti-inflammatory for aphthous ulcers
• Amlexanox 5% paste: Anti-inflammatory; accelerates healing of aphthous ulcers

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10. Peutz-Jeghers Syndrome

1. Mucocutaneous melanin pigmentation (perioral, perinasal, buccal mucosa, fingers, lips, peri-anal)
2. Gastrointestinal hamartomatous polyps (small intestine most common, also colon, stomach)
3. Increased cancer risk

• Multiple dark brown/black macules on lips (vermilion border), buccal mucosa, gingiva, palate
• Macules may fade with age (except buccal mucosa lesions which persist - diagnostic clue)
• No malignant potential for the oral macules themselves

• Small intestinal polyps → intussusception, obstruction, rectal bleeding
• Polyps are hamartomas (not adenomas); low but real malignant potential

• Regular surveillance: Colonoscopy, upper endoscopy, small bowel imaging, breast MRI
• Polypectomy for large polyps
• Genetic counseling

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11. Trismus [2M]

• Pericoronitis (wisdom tooth infection - most common dental cause)
• Dental abscess with spread to masticator space
• Post-extraction (dry socket, muscle injury)
• Temporomandibular joint disorders
• Fractured mandibular condyle

• OSMF (most common cause of progressive trismus in South Asia)
• Parapharyngeal/pterygomandibular/masseteric space abscess
• Osteomyelitis of jaw
• Mumps (parotitis)

• Fracture of zygomatic arch or mandibular ramus
• Hematoma in masticatory muscles
• Post-radiotherapy fibrosis

• Tetanus (lockjaw - tonic spasm of masseter; most serious cause)
• Rabies
• Meningitis, encephalitis

• Malignant tumor invading masticator space
• Post-radiation fibrosis

• Phenothiazines (extrapyramidal trismus)
• Succinylcholine (masseter rigidity)

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12. Causes for Bleeding in Oral Cavity

• Trauma (laceration, extraction socket, biting)
• Gingival bleeding: gingivitis, periodontitis, ANUG
• Pericoronitis
• Oral ulcers/erosions
• Vascular lesions: hemangioma, AVM, pyogenic granuloma, Kaposi's sarcoma
• Oral malignancy (ulcerated SCC)
• Post-surgical/post-extraction bleeding

• Thrombocytopenia (ITP, aplastic anemia, leukemia, drug-induced)
• Platelet function disorders (von Willebrand disease, Glanzmann thrombasthenia)

• Hemophilia A (Factor VIII deficiency)
• Hemophilia B/Christmas disease (Factor IX deficiency)
• Vitamin K deficiency
• Liver disease (reduced clotting factor synthesis)
• Warfarin/anticoagulant therapy (most common systemic cause encountered in dental practice)

• Hereditary hemorrhagic telangiectasia (Osler-Weber-Rendu)
• Scurvy (Vitamin C deficiency)
• Henoch-Schonlein purpura

• Leukemia (infiltration + thrombocytopenia)
• Multiple myeloma

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13. Exfoliative Cytology

1. Clean the mucosal surface (gauze wipe)
2. Scrape the lesion firmly with a metal spatula, tongue depressor, or cytology brush
3. Immediately spread cells on a glass slide in a thin, even layer
4. Fix immediately (within seconds) with 95% ethyl alcohol or cytospray to prevent drying artifact
5. Stain with Papanicolaou (Pap) stain (standard); also Giemsa, acridine orange, Feulgen stain

• Class I: Normal cells
• Class II: Atypical but benign
• Class III: Cells suggestive of malignancy (dysplastic)
• Class IV: Strongly suggestive of malignancy
• Class V: Malignant cells

• Simple, quick, non-invasive, inexpensive
• No anesthesia required
• Useful for screening large populations
• Can sample large areas, multiple sites

• Only surface cells examined - subsurface changes missed
• High false-negative rate (~20-30%) - cannot diagnose subepithelial lesions
• Cannot replace biopsy - positive/suspicious results must be followed by biopsy
• Poor preservation if not fixed immediately
• Cannot distinguish carcinoma in situ from invasive carcinoma

• Screening for oral cancer/premalignant lesions
• Diagnosis of herpes simplex (Tzanck cells/multinucleated giant cells)
• Candidiasis (hyphae/pseudohyphae seen)
• Monitoring patients after cancer treatment

• Oral CDx (brush biopsy): Computer-assisted analysis; samples all epithelial layers; reduces false negatives
• Liquid-based cytology

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14. Halitosis

• Poor oral hygiene (most common) - bacterial putrefaction of food debris
• Periodontal disease/gingivitis - most common pathological cause
• ANUG
• Tongue coating (dorsal tongue bacteria - major source)
• Dry mouth (xerostomia)
• Dental caries, pericoronitis, dental abscess
• Dentures (food retention)
• Oral ulcers

• Respiratory: Sinusitis, tonsillar crypts, lung abscess, bronchiectasis
• GI: GERD, Zenker's diverticulum, H. pylori
• Renal failure (urinous/ammonia odor)
• Liver failure (fetor hepaticus - musty, sweet)
• Diabetes (ketoacidosis - fruity/acetone smell)
• Drugs: DMSO, disulfiram, isosorbide dinitrate

• Tongue scraping (most effective single measure)
• Thorough oral hygiene (brushing, flossing)
• Chlorhexidine mouthwash
• Zinc-containing toothpastes/rinses (neutralize VSCs)
• Treat periodontal disease
• Address xerostomia
• Treat systemic cause if present

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15. Brachytherapy

• LDR (Low dose rate): <2 Gy/hr; sources remain in place for days
• HDR (High dose rate): >12 Gy/hr; brief applications, multiple fractions; safer for staff

• Oral tongue cancer (T1-T2)
• Floor of mouth cancer
• Lip cancer
• Soft palate, tonsillar tumors
• Boost dose after external beam radiotherapy

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16. Lip Prints (Cheiloscopy)

• Lip prints left on glasses, skin, cigarette butts can be used as evidence at crime scenes
• Identifies individuals at mass disasters
• Useful in gender determination (females tend to have Type I and II; males Type III and IV)

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17. Functions of the Maxillary Sinus

1. Resonance: Acts as resonance chamber for voice (paranasal sinuses contribute to voice quality)
2. Humidification and warming of inspired air
3. Olfaction: Mucus drainage aids olfaction
4. Lightening the skull: Reduces cranial weight
5. Absorbs mechanical shocks (trauma buffer for the face/orbit)
6. Mucus production and drainage: Mucociliary clearance
7. Immune defense: Mucosa contains IgA, lysozyme

• Roots of maxillary posterior teeth (especially 1st and 2nd molars, 2nd premolars) may project into or be very close to the sinus floor
• Extraction may cause oro-antral communication
• Periapical infection of these teeth can cause sinusitis (odontogenic sinusitis)
• Sinus lift procedures required before implant placement in resorbed posterior maxilla

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18. Bite Mark Analysis

• Used in criminal cases (assault, homicide, sexual offenses, child abuse)
• Bite marks on victims and sometimes on suspects

1. Photography: High-resolution photos with scale (ABFO No.2 scale) at 90° angle; UV photography highlights older bite marks
2. Swabbing: DNA sampling of saliva from bite area (before cleaning)
3. Casting/impression: Dental stone impressions of bite mark on flexible substrates
4. Comparison: Dental models/impressions of suspects compared to bite mark shape
5. Overlay technique: Transparent overlay of suspect's teeth placed over bite mark photograph
6. Computer-aided analysis: Digital image analysis for objective comparison

• Take dental impressions of suspects
• Analyze arch form, tooth size/spacing, rotations, chipped/missing teeth
• Expert witness testimony in court

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19. Biopsy in Oral Medicine

• Any oral lesion persisting >2-3 weeks without identifiable cause
• Any red (erythroplakia), white (leukoplakia), or mixed lesion
• Ulcers with indurated margins
• Suspected malignancy
• Vesiculobullous lesions (for DIF + H&E)
• Suspected systemic disease manifestation
• Masses or swellings of unknown etiology

• Take from the most representative area (active edge of lesion, not necrotic center)
• For vesiculobullous lesions: Perilesional tissue for DIF
• For leukoplakia: Bimanual palpation - take from erythroplakic, nodular, or thickest areas
• Avoid using electrocautery (artifact); use scalpel

• H&E staining (routine)
• Special stains: PAS (candida), ZN (TB), Congo red (amyloid)
• DIF (immunofluorescence) - for autoimmune bullous disorders
• IHC (immunohistochemistry) - for tumor markers

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20. Wound Certificate

1. Date, time, and place of examination
2. Patient's particulars (name, age, sex, occupation)
3. History given by the patient (in quotation marks if verbatim)
4. General examination findings
5. Description of each wound/injury:
   • Site (precise anatomical location)
   • Shape, size (measured with scale)
   • Nature: contusion, laceration, abrasion, incised wound, puncture wound, fracture
   • Edges: regular/irregular; margins; floor/depth
   • Age of wound (fresh/old)
   • Presence of foreign body, bleeding
6. Opinion on:
   • Probable weapon used
   • Nature: self-inflicted or by another person
   • Severity: simple/grievous (legal classification)
7. Treatment given
8. Signature and designation of certifying doctor

• Abrasion: Superficial scraping of skin
• Contusion/Bruise: Blunt force without skin breach
• Laceration: Irregular tear from blunt force
• Incised wound: Clean cut from sharp instrument (knife)
• Puncture/Stab: Deep, narrow wound

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21. Role of Dentist in Mass Disasters

1. Primary identifiers (most reliable):
   • Dental identification (DVI - Disaster Victim Identification)
   • Fingerprints
   • DNA analysis
2. Secondary identifiers: Personal effects, physical description, scars

• Collect pre-existing dental records: X-rays, charts, study models, photographs from dentists, dental offices, hospitals
• Record restorations, missing teeth, unique features

• Examine charred/decomposed remains (teeth are the most durable human tissue - withstand fire, decay)
• Dental examination: Record all teeth present/absent, restorations, prostheses, unique features
• Radiographs of teeth and jaws
• DNA from dental pulp

• Compare AM and PM dental records for identification (reconciliation)
• DVI teams use Plassdata/WinID software

• Age estimation from dental development (children) or attrition/cementum annulation (adults)
• Sex determination from tooth morphology
• Bite mark analysis

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PART B: DENTAL RADIOLOGY - X-RAY PHYSICS

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22. Production of X-rays (X-ray Tube Components and Functions)

1. Bremsstrahlung (Braking) Radiation (~80-95%):

• High-speed electrons decelerate and change direction when passing near tungsten nuclei
• Kinetic energy converted to X-ray photons
• Produces a continuous spectrum of X-ray energies
• Energy range: 0 to maximum (kVp)

2. Characteristic Radiation (~5-20%):

• Electron ejects an inner-shell (K-shell) electron from tungsten atom
• Outer shell electron drops down to fill vacancy → emits X-ray photon with energy = energy difference between shells
• Produces specific discrete energy X-rays characteristic of tungsten
• Only occurs if tube voltage >69.5 kV (tungsten K-shell binding energy)

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23. Tube Current and Tube Voltage

• Applied between cathode and anode
• Determines the energy (penetrating power/quality) of X-ray beam
• Higher kVp → more energetic, more penetrating X-rays → harder beam → lower patient dose → less contrast but more latitude
• Typical dental range: 60-90 kVp (intraoral); 70-90 kVp (panoramic)

• Current through the filament
• Determines the number (quantity) of electrons produced per unit time → determines number of X-rays produced
• Higher mA → more X-rays → greater film density/image brightness
• Combined as mAs (milliampere-seconds) = quantity of radiation

• kVp controls quality (energy/penetration)
• mA controls quantity (number of photons)
• Increasing kVp also slightly increases quantity
• Increasing mAs increases quantity proportionally

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24. Collimation

1. Reduces unnecessary radiation to patient (reduces dose to non-essential tissues)
2. Reduces scatter radiation (improves image quality)
3. Defines beam shape

• Open-ended cylinder that directs the beam
• Long PID (>20 cm): Reduces beam divergence, better image quality, lower dose
• Short PID (<20 cm): More divergence, more dose

• Rectangular collimation can reduce patient dose by 50-70% compared to round
• Required by radiation safety regulations (ALARA principle)

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25. Filtration

• Removes long-wavelength, low-energy photons that would not contribute to the image
• These would only increase patient dose (absorbed by superficial tissues)
• Produces a more penetrating, homogeneous beam
• Reduces patient skin dose significantly

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26. Radiation Protection of the Operator

• Operator stands at least 2 meters (6 feet) from the X-ray source during exposure
• Stand at 90-135° to the primary beam (not in front of or behind the tube)
• Inverse square law: Doubling distance reduces dose to 1/4

• Lead apron is for patients (not primarily for operator)
• Lead-lined walls of X-ray room (minimum 1.5 mm lead equivalent)
• Lead-lined door or barrier with viewing window
• Operator stands behind barrier or leaves room during exposure

• Film badge/OSL dosimeter - worn on collar; monthly assessment
• TLD (Thermoluminescent dosimeter) - LiF crystals; most accurate; reusable
• Pocket dosimeter - immediate reading
• Ring dosimeter - for hands

• 20 mSv/year (averaged over 5 years)
• 50 mSv maximum in any single year
• Pregnant workers: 1 mSv/month to fetus
• General public: 1 mSv/year

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27. Radiolysis of Water

• Hydroxyl radical (OH•) - most damaging; highly reactive oxidizing agent
• Hydrogen radical (H•)
• Combined products: H₂O₂ (hydrogen peroxide), HO₂• (hydroperoxide radical)

• ~70% of cell content is water
• ~80% of radiation damage is indirect (via free radical formation from water radiolysis)
• OH• attacks DNA → strand breaks, base damage, cross-links
• Direct damage: 20% (ionization of DNA directly)

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28. Radiation Caries

1. Radiation damages salivary glands (especially parotid) → xerostomia (most important cause)
2. Reduced saliva = loss of buffering, antimicrobial properties (IgA, lysozyme), remineralization
3. Shift in oral flora: Streptococcus mutans, Lactobacilli increase dramatically
4. Dietary changes (soft, cariogenic diet due to mucositis pain)
5. Direct radiation effect on enamel/dentin (minor)

• Rapid onset (within 3-6 months after RT)
• Cervical caries encircling teeth at gingival margin (most characteristic pattern)
• Brown-black discoloration
• Progressive, circumferential destruction
• Can affect all teeth simultaneously
• May lead to crown amputation

• Custom fluoride trays before RT; daily application of 1.1% sodium fluoride gel
• Chlorhexidine rinses (0.12%)
• Salivary substitutes
• IMRT to spare salivary glands
• Thorough dental assessment and extractions BEFORE radiation (prevent osteoradionecrosis)
• Dietary advice

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29. Inverse Square Law [2M]

• At 2 m: 100/4 = 25 mR/hr
• At 3 m: 100/9 = 11 mR/hr

• Explains why operator should stand at least 2 meters away during X-ray exposure
• Justifies use of long PIDs (longer target-film distance = less divergence and less dose per unit area)
• Relates to radiation protection (distance is the simplest protective measure)

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30. Scattered Radiation

• Patient tissues (main source)
• Walls, floor, equipment

1. Compton (incoherent) scattering (most important in diagnostic range): Incident photon ejects an outer-shell electron (recoil/Compton electron); photon continues at lower energy and changed direction
2. Coherent/Thomson scattering: Photon interacts with bound electron; energy unchanged, direction changed; occurs at low energies

• Degrades image quality (reduces contrast, causes film fog)
• Increases patient dose (scatter absorbed by adjacent tissues)
• Radiation hazard to operator

• Collimation (most effective - limits beam size)
• Grids (in panoramic, cephalometric - absorbs scatter)
• High kVp (paradoxically reduces total scatter by reducing photoelectric absorption)
• Lead aprons for patient
• Short exposure times

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31. Roentgen

• 1 Roentgen = 2.58 × 10⁻⁴ Coulombs/kg of air
• SI unit of exposure: Coulombs/kg (C/kg)
• 1 R = 0.000258 C/kg

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32. Interactions of X-rays with Matter [4M/2M]

• Photoelectric effect dominates in bone/enamel → creates contrast
• Compton scatter dominates in soft tissue → creates scatter/fog

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33. Coherent Scattering

• Also called Thomson scattering or Rayleigh scattering
• Incident photon's energy = emitted photon's energy (no energy transfer)
• Change in direction only
• Occurs at low photon energies (<15 keV)
• Does not contribute to ionization or biological damage directly
• In dental radiography: minor contributor to scatter fog at low kVp
• No ionization - photon energy unchanged

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34. Dosimetry

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35. TLD (Thermoluminescent Dosimeter)

1. Radiation excites electrons in LiF crystals to higher energy "trap" states
2. Electrons stored in traps; energy stored proportional to dose received
3. When heated to ~200-300°C: electrons return to ground state → emit visible light (glow)
4. Light measured by photomultiplier tube → proportional to radiation dose

• Accurate and sensitive (measures doses from 0.01 mGy to 10 Gy)
• Small, tissue-equivalent (LiF has similar Z to soft tissue)
• Reusable (after heating and annealing)
• Can be stored for months without significant fading
• Measures cumulative dose
• Available as chips, powder, rods

• Reading process destroys the stored information (cannot re-read)
• Requires laboratory processing (not immediate reading)
• More expensive than film badges

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36. Focal Trough and Focal Spot

Focal Trough (Image Layer / Tomographic Layer) - for Panoramic Radiography:

• The horseshoe-shaped, three-dimensional curved zone within which objects are acceptably sharp on a panoramic radiograph
• Only structures within the focal trough are in focus; structures outside are blurred
• Shape follows the average curvature of the dental arches
• Width: ~20-25 mm
• Too far anterior: Teeth appear narrow, blurred; spine shadow absent
• Too far posterior: Teeth appear wide, blurred; spine ghost image superimposed
• Patient must be positioned correctly so dental arches lie within the focal trough

Focal Spot:

• The area on the anode (tungsten target) where the electron beam strikes and X-rays are produced
• Actual focal spot: True area of electron bombardment (larger)
• Effective focal spot: Projected area seen from the direction of the useful beam (smaller, due to line focus principle)
• Line focus principle: Angling the target face (typically 6-20°) makes the effective focal spot smaller → sharper images
• Smaller effective focal spot → better image sharpness/resolution
• Penumbra: Geometric unsharpness due to focal spot size; smaller focal spot = less penumbra = sharper image

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PART C: IMAGING PRINCIPLES AND TECHNIQUES

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37. Panoramic Radiography (OPG) - Advantages, Disadvantages, Technique

1. Patient stands upright, bites on the bite peg (chin supported)
2. Frankfort plane (tragus to infraorbital rim) horizontal
3. Midsagittal plane vertical
4. Teeth in the bite plane
5. Tongue pressed against the palate (eliminates airspace shadow over roots)
6. Remove all metallic prostheses

• Single film shows both jaws, TMJs, sinuses, lower skull base
• Low patient radiation dose
• Quick, easy
• Useful in children, disabled, trismus patients (no intraoral film placement)
• Broad survey - useful for initial assessment, orthodontic planning, implant planning, pathology screening

• Poor detail/resolution (not diagnostic for caries, periodontal bone level)
• Geometric distortion (magnification ~20-25%, varies by region)
• Overlapping of anterior teeth (landmark imprecision for the anterior region)
• Ghost images of contralateral structures
• Positioning errors common (ghost images, blurring)
• Superimposition of cervical spine over middle third
• Not useful for periapical assessment

• Assessment of impacted wisdom teeth
• Orthodontic assessment
• Trauma (fractures)
• Periodontal disease (bone levels)
• Implant planning
• Developmental anomalies
• TMJ assessment (basic)
• Third molar evaluation

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38. Bisecting Angle Technique

• The central ray is directed perpendicular to the bisector of the angle formed between the long axis of the tooth and the film/sensor
• This ensures the image length equals the true tooth length (no elongation or foreshortening)
• Based on geometry: two right triangles sharing a common hypotenuse are equal

• Geometric distortion (less accurate than paralleling technique)
• Variable angulation causes inconsistent images
• More scatter
• More distortion of adjacent structures

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39. Paralleling Technique (Long-Cone Technique)

• Film/sensor placed parallel to long axis of tooth
• Central ray directed perpendicular to both the film and the tooth
• Long target-film distance (≥40 cm) to compensate for increased object-film distance

• Accurate representation of tooth length and root morphology
• Less geometric distortion
• Reproducible images (film holders standardize positioning)
• Lower patient dose (rectangular collimation easily used)
• Better for monitoring bone levels over time

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40. Intraoral Periapical (IOPA) Radiograph

• Detection of periapical pathology (abscess, granuloma, cyst)
• Caries detection (interproximal)
• Periodontal bone assessment
• Root morphology
• Root fracture assessment
• Pre-/post-operative endodontic radiographs
• Eruption assessment

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41. Composition of X-ray Film and Latent Image Formation

• Polyester (cellulose triacetate previously)
• Transparent; blue tint added for comfort

• Thin layer bonding emulsion to base

• Silver halide crystals (mainly silver bromide AgBr, some silver iodide AgI) suspended in gelatin
• Crystal size determines speed and resolution (larger = faster but lower resolution)

• Thin gelatin layer; protects emulsion

1. X-ray photons strike AgBr crystals → photoelectric effect with Br⁻ ion → electron liberated
2. Electron migrates to sensitivity speck (silver sulfide impurity)
3. Silver ion (Ag⁺) attracted to sensitivity speck → reduced to metallic Ag atom
4. Process repeats → cluster of silver atoms at sensitivity speck = latent image center
5. No visible change in film at this stage - requires development

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42. Film Processing (Development and Fixation)

• Developer solution reduces exposed silver halide to black metallic silver
• Common developers: Hydroquinone (high contrast, slow), Elon/Metol (low contrast, fast), combined for best results
• Alkali (sodium carbonate/sodium hydroxide): Activator - swells gelatin, increases activity
• Preservative (sodium sulfite): Prevents oxidation of developer
• Restrainer (potassium bromide): Prevents fogging of unexposed areas

• Removes unexposed silver halide → makes image permanent
• Sodium/ammonium thiosulfate (hypo) - main fixing agent
• Potassium alum - hardener
• Glacial acetic acid - acidifier/stops development
• Sodium sulfite - preservative
• Duration: 2× development time ("fix for twice the clearing time")

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43. Causes for Faulty Radiographs and Rectifications

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44. OPG - Intensifying Screens and Grids

• Used in extraoral (panoramic, cephalometric) cassettes
• Crystals (calcium tungstate, rare earth - gadolinium, lanthanum) absorb X-ray → emit visible/UV light → exposes film
• Reduces patient dose by 50-70× (less X-ray exposure needed)
• Reduces motion blur (shorter exposure time)
• Disadvantage: Reduces image resolution/detail compared to direct X-ray exposure

• Used to reduce scatter reaching the film in extraoral radiography
• Made of lead strips with aluminum interspaces
• Grid ratio = height of lead strips / width of interspaces (e.g., 8:1, 10:1)
• Higher grid ratio = more scatter removal but higher patient dose
• Types:
  • Parallel/linear grid
  • Focused grid (lead strips angled toward focal point)
  • Oscillating/Bucky grid (moves during exposure to blur grid lines from image)
  • Cross-hatch/crossed grid (two parallel grids at 90°)

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45. Water's View (Occipito-Mental View)

• Patient: Chin extended, forehead-nose-chin contact with Bucky/cassette
• Mento-mental line at 45° to the film
• Central ray perpendicular to film, directed to midpoint of film

• Sinusitis (fluid level, mucosal thickening, opacification)
• Zygomatic fractures
• Orbital blow-out fracture
• Sinus tumors/cysts

• Shows frontal sinuses and ethmoid sinuses best

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46. Bitewing Radiography

• Film/sensor placed parallel to crowns of both arches
• Patient bites on the tab/wing holding the film
• Central ray directed at +5° to +8° vertical angulation, perpendicular to film horizontally

1. Detection of interproximal caries (best technique)
2. Assessment of crestal alveolar bone levels (early periodontal disease)
3. Detection of recurrent/secondary caries under restorations
4. Assessment of restoration contours (overhangs, open contacts)
5. Calculus detection subgingivally

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47. SLOB Rule (Same Lingual, Opposite Buccal)

• Take two periapical radiographs with different horizontal angulations (tube moved mesially or distally)
• If an object moves in the same direction as the tube shift → object is Lingual (palatal)
• If an object moves in the opposite direction to the tube shift → object is Buccal

• Locating supernumerary teeth
• Localizing impacted canines (palatal or buccal)
• Locating foreign bodies
• Determining root positions in multi-rooted teeth
• Identifying which of two superimposed roots is which

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48. ALARA Principle

1. Prescribe radiographs only when clinically justified (selection criteria)
2. Use fastest film/digital sensors (F-speed film or digital)
3. Use rectangular collimation (reduces dose by 50-70% vs. round)
4. Use lead apron and thyroid collar
5. Use IMRT/long cone paralleling technique
6. Do not retake films unnecessarily
7. Proper patient positioning to avoid retakes
8. Regular equipment maintenance and calibration
9. Staff monitoring and protection (2 m distance, barriers)

• Justification: Benefit > risk for each exposure
• Optimization: ALARA - use lowest dose to achieve diagnostic purpose
• Dose limitation: Keep below MPD values

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49. CBCT (Cone Beam CT)

• Lower dose (~50-80% less than medical CT)
• Better spatial resolution for bone
• Faster scan time
• Smaller, more affordable equipment
• Isotropic voxels (same resolution in all planes)
• Sub-millimeter resolution possible

• Higher dose than conventional 2D dental radiographs
• More scatter (degrades soft tissue contrast)
• Poor soft tissue differentiation
• More expensive than conventional radiography
• Requires additional training for interpretation

• Implant planning (bone volume, density, proximity to nerve/sinus)
• Impacted/supernumerary tooth localization (especially for surgery planning)
• Temporomandibular joint assessment
• Orthodontic assessment (airway, skeletal)
• Endodontic complex cases (root canal anatomy, resorption)
• Jaw pathology (extent of cysts, tumors)
• Trauma (facial fractures)
• Cleft palate assessment

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50. MRI - Indications and Contraindications

• TMJ disc assessment (gold standard - visualizes disc position and morphology)
• Salivary gland tumors (characterization)
• Soft tissue lesions
• Perineural spread of oral cancer
• Skull base involvement
• Vascular malformations (hemangioma, AVM)
• Sjogren's syndrome (parotid)
• Pre-surgical planning for jaw tumors
• Bone marrow disorders

• Cardiac pacemaker/ICD (absolute)
• Ferromagnetic intracranial aneurysm clips (absolute)
• Cochlear implants (most absolute)
• Ferromagnetic intraocular foreign body
• Metallic orbital implants
• First trimester pregnancy (relative)
• Claustrophobia (use open MRI or sedation)

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51. Digital Radiography

1. PSP (Photostimulable Phosphor/CR): BaFBr plate absorbs radiation; laser scanning releases light (OSL); converted to digital signal; plate reusable
2. CCD/CMOS (Direct/Wired sensors): CCD = charge-coupled device; direct electronic signal; immediate image; wired sensors
3. CMOS sensors: Complementary metal oxide semiconductor; similar to CCD but lower power consumption; basis of modern Planmeca, Acteon sensors

• Immediate image (no processing time)
• Lower patient dose (40-60% less than F-speed film)
• No darkroom/chemicals required
• Images stored electronically (easy retrieval, comparison)
• Can be enhanced (contrast, brightness, magnification)
• Easy transmission (teledentistry)
• Environmentally friendly (no chemical waste)
• Long-term storage (no film degradation)

• High initial cost
• Sensor rigidity (less comfortable than film)
• Smaller image area (especially sensors)
• Need for infection control (sensor covers)
• Cybersecurity concerns (data protection)
• Screen resolution limits ultimate image quality

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52. Ghost Images in OPG

• Cervical spine vertebrae - midline shadow
• Soft palate/tongue/pharyngeal airspace
• Earrings - ghost appears on opposite side, higher up
• Nose rings, metallic prostheses, orthodontic bands
• Hyoid bone (bilateral shadows)
• Hard/soft palate - horizontal radiopaque band

• Magnified, blurred compared to real image
• Located higher
• Located on the opposite side to the real object

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53. Tyre Track Effect

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PART D: RADIOGRAPHIC INTERPRETATION

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54. Differences Between Periapical Abscess, Granuloma, and Cyst

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55. Dentigerous Cyst - Radiographic Features

• Well-defined unilocular radiolucency surrounding/attached to the crown of an unerupted tooth at the cemento-enamel junction (CEJ)
• Minimum size considered cystic: >3-4 mm pericoronal space
• Scalloped or smooth corticated border (radiopaque rim)
• Root not involved in the radiolucency (only crown)
• May displace the involved tooth significantly
• Associated tooth most commonly: mandibular 3rd molar > maxillary canine > maxillary 3rd molar
• Variations:
  • Central: Crown symmetrically surrounded
  • Lateral: Lateral to crown
  • Circumferential: Entire tooth enveloped

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56. Multilocular Radiolucencies of the Jaw

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57. Unilocular Radiolucency of the Jaw

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58. Radiographic Interpretation of Caries

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59. Radiographic Appearance of Osteosarcoma and Ewing's Sarcoma

• "Sunburst" pattern - radiating spicules of new bone perpendicular to cortex
• Codman's triangle - triangular periosteal elevation at tumor margins
• Symmetric widening of periodontal ligament space - earliest radiographic sign
• Mixed osteolytic/osteoblastic pattern (most common)
• Cortical destruction and expansion
• Ill-defined margins

• More commonly involves long bones; jaw involvement less common (mandible)
• "Onion skin" pattern - multiple parallel layers of new periosteal bone (layered periosteal reaction)
• Poorly defined, permeative, "moth-eaten" osteolytic lesion
• No intralesional calcification
• Soft tissue extension
• Affects younger patients (1st-2nd decade)

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60. Periapical Radiolucencies - Differential Diagnosis

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61. Mixed Radiolucent and Radiopaque Lesions of the Jaw

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62. Differences Between Periapical and Periodontal Abscess

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