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ORAL & MAXILLOFACIAL SURGERY - Comprehensive Answers

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SECTION 1: ANESTHESIA

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Q. Define Local Anesthesia. Explain Theories & Mechanism of Action of LA

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Mechanism of Action

1. The drug is injected in its unionized (lipophilic base) form - this crosses the lipid nerve membrane
2. Inside the cell, the drug re-ionizes (becomes the charged cation form)
3. The charged (ionized) form enters and binds to a receptor site within the Na+ channel, blocking it
4. No Na+ influx → no depolarization → no action potential → anesthesia

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Theories of Local Anesthesia

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Structure of LA Molecules

• Esters (procaine, tetracaine, benzocaine): metabolized by plasma cholinesterase; PABA metabolite is allergenic
• Amides (lidocaine, bupivacaine, mepivacaine, ropivacaine, prilocaine): metabolized in the liver; true allergy extremely rare

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Role of Vasoconstrictors (Epinephrine)

• LA drugs cause vasodilation (except cocaine)
• Adding epinephrine: reduces absorption from site, prolongs duration, reduces systemic toxicity, reduces bleeding
• Contraindicated in: end-artery regions (fingers, toes, nose, ear, penis), patients on non-selective beta-blockers, thyrotoxicosis, uncontrolled hypertension

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Q. Inferior Alveolar Nerve Block (IANB) - Landmarks, Technique, Complications

Landmarks

• Coronoid notch - deepest concavity on the anterior border of ramus (palpated with index finger)
• Pterygomandibular raphe - visible as a whitish fold when mouth is open
• Pterygomandibular triangle - bounded anteriorly by pterygomandibular raphe, posteriorly by medial surface of ramus
• Occlusal plane of mandibular teeth - needle directed 1 cm above this plane
• Lingula - bony projection at medial surface of ramus where nerve enters mandibular foramen (injection target)

Technique (Conventional/Halstead technique)

1. Patient's mouth wide open; barrel of syringe over premolars of opposite side
2. Palpate the coronoid notch with the thumb of the opposite hand
3. Insert needle at the medial surface of the ramus, 1 cm above the mandibular occlusal plane, aiming toward the pterygomandibular triangle
4. Advance approximately 20-25 mm until bone (medial surface of ramus near lingula) is contacted
5. Withdraw 1 mm; aspirate (2 planes), then deposit 1.5 mL slowly over 60 seconds
6. Withdraw 5-6 mm, deposit 0.5 mL for lingual nerve
7. Withdraw fully; insert near mucobuccal fold for long buccal nerve

Complications

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Q. Infraorbital Nerve Block - Landmarks, Technique, Complications

Landmarks

• Infraorbital foramen: Located approximately 1 cm below the inferior orbital rim, in line with the pupil (mid-pupillary line), at the junction of medial 2/3 and lateral 1/3 of infraorbital rim
• Palpated as a notch with slight pressure, patient feels a twinge

Technique (Intraoral approach)

1. Retract upper lip upward; insert needle in mucobuccal fold above the apex of the maxillary first premolar
2. Direct the needle upward, inward, and backward toward the infraorbital foramen
3. Advance until resistance of periosteum is felt (approximately 16 mm depth)
4. Aspirate, deposit 1-1.5 mL slowly
5. Simultaneously apply digital pressure over the infraorbital foramen to direct solution into the foramen

Technique (Extraoral approach)

1. Palpate the infraorbital foramen
2. Insert needle 1 cm below the foramen; direct upward and inward
3. Aspirate and deposit 1-1.5 mL

Complications

• Hematoma (ecchymosis below eyelid)
• Intravascular injection
• Inadvertent intraorbital injection (diplopia, blindness - rare)
• Injury to infraorbital nerve (paresthesia)
• Penetration into nasal cavity

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Q. Gow-Gates Technique

• A mandibular block that anesthetizes the entire V3 distribution with a single injection
• Needle is directed to the neck of the mandibular condyle
• Higher success rate (~99%) than IANB; fewer positive aspirations
• Patient opens wide; syringe directed from contralateral corner of mouth toward tragus-commissure line
• Less risk of intravascular injection as needle is away from inferior alveolar vessels

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SECTION 2: EXODONTIA & IMPACTED TEETH

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Q. Principles of Dental Extraction

• Non-restorable teeth (extensive caries, crown/root fracture)
• Advanced periodontal disease
• Impacted teeth causing pathology
• Orthodontic therapy requirements
• Supernumerary or malposed teeth
• Teeth associated with cysts/tumors
• Prior to radiation therapy to the jaw
• Fractured roots after trauma

• Local: acute infection (relative - often resolve with antibiotics first), malignancy (biopsy first), irradiated bone
• Systemic: uncontrolled diabetes, uncontrolled hypertension, bleeding disorders (hemophilia), blood dyscrasias, pregnancy (1st and 3rd trimester avoid elective), patients on bisphosphonates (MRONJ risk), immunocompromised

1. Adequate anesthesia - ensure complete before proceeding
2. Reflection of mucoperiosteum - if needed (surgical)
3. Expansion of socket - use elevators in a controlled manner
4. Luxation and delivery of the tooth with forceps using slow, deliberate, controlled movements
5. Curettage of socket - remove granulation tissue, follicle
6. Hemostasis - pressure with gauze; suturing if needed
7. Post-extraction instructions - no rinsing for 24 hours, avoid smoking, soft diet

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Q. Classification of Impacted Mandibular Third Molar

• Mesioangular (most common, 43%) - easier to remove
• Vertical (2nd most common, 38%)
• Distoangular (6%) - most difficult to remove
• Horizontal (3%)
• Others: Buccoangular, Linguoangular, Inverted

• Class I, II, III - based on relationship to anterior border of ramus (space availability)
• Position A, B, C - based on depth (position of occlusal surface relative to second molar)

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Q. Surgical Removal of Horizontally Impacted Mandibular Third Molar

1. Anesthesia: IANB + long buccal nerve block
2. Incision: Ward's incision (envelope flap) or triangular flap
3. Mucoperiosteal flap elevation
4. Bone removal: bur or chisel along buccal and distal aspects to expose crown
5. Tooth sectioning: Section tooth at the CEJ (dentirotomy) - separate crown from root
6. Crown removal with elevator
7. Root delivery
8. Socket irrigation and debridement
9. Flap repositioning and suturing (interrupted or figure-of-8 sutures)

• Dry socket (acute alveolar osteitis) - most common (2-5%)
• Inferior alveolar nerve damage (paresthesia)
• Lingual nerve damage
• Fracture of mandible
• Displacement into infratemporal fossa
• Post-extraction hemorrhage
• Trismus

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Q. Dry Socket (Acute Alveolar Osteitis)

• Loss/disintegration of blood clot from the socket before healing is complete
• Pain begins 2-4 days post-extraction, radiating to ear/temple
• Foul odor, empty socket with exposed bone
• Risk factors: mandibular molars, smoking, poor oral hygiene, oral contraceptives, traumatic extraction
• Management: Irrigation with saline, placement of Alvogyl (eugenol-soaked dressing), analgesics, antibiotics if systemic signs present
• Heals by secondary intention in 7-14 days

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Q. Birn's Hypothesis (Pathogenesis of Dry Socket)

• Fibrinolysis of the blood clot by plasmin (via tissue activators and bacterial kinases)
• Kinins released cause intense pain
• Bacteria (especially Treponema denticola) and tissue activators activate plasminogen → plasmin → clot dissolution

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SECTION 3: INFECTIONS

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Q. Ludwig's Angina - Definition, Etiology, Clinical Features, Management

• 80-90% odontogenic origin - most commonly mandibular second and third molars
• Polymicrobial: streptococci, staphylococci, Bacteroides, Fusobacterium, mixed anaerobes
• Non-dental: floor of mouth laceration, submandibular sialadenitis, mandibular fracture

• Bilateral submandibular swelling - "bull neck" appearance
• Woody/brawny induration (hallmark) - no fluctuation (not an abscess initially)
• Elevation and posterior displacement of tongue - key sign
• Trismus
• Drooling, dysphagia, odynophagia
• Stridor, respiratory distress (from airway compromise - the most dangerous feature)
• Fever, toxicity, tachycardia
• Voice change (hot potato voice, muffled)

• CT scan of neck - extent of spread, to detect pus pockets
• Chest X-ray (mediastinitis)
• FBC, blood cultures, blood glucose
• WBC elevated, raised ESR/CRP

1. AIRWAY is the priority - awake fiberoptic intubation, or tracheostomy under LA if intubation not possible
2. Antibiotics IV: High-dose IV penicillin + metronidazole; clindamycin if penicillin allergic; add Gram-negative coverage (gentamicin) if source uncertain
3. Surgical drainage when fluctuance develops - bilateral submandibular incisions (Henny & Gustafson approach); through-and-through drain
4. IV fluids, nutritional support
5. Steroids (controversial) - dexamethasone may reduce swelling
6. ICU admission, close monitoring
7. Dental extraction of offending tooth after condition stabilizes

• Airway obstruction (commonest cause of death)
• Mediastinitis (descending necrotizing mediastinitis)
• Aspiration pneumonia
• Septicemia
• Jugular vein thrombosis
• Cavernous sinus thrombosis
• Pericarditis

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Q. Osteomyelitis of the Jaw - Classification, Clinical Features, Management

• Acute: Acute suppurative, Acute non-suppurative
• Chronic: Chronic suppurative, Chronic sclerosing (focal/diffuse), Chronic Garre's (proliferative periostitis)
• Specific: Actinomycotic, syphilitic, tuberculous
• Special forms: Osteoradionecrosis, MRONJ

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Acute Suppurative Osteomyelitis

• Severe, deep-seated throbbing pain
• Pyrexia, malaise, leukocytosis
• Trismus (if masticator space involved)
• Tender regional lymphadenopathy
• Teeth in affected area are tender, mobile
• Mental nerve paresthesia (lower lip numbness - "Vincent's sign") if inferior alveolar nerve involved
• Sinus/fistula formation later
• Foul taste from pus

• Early acute: No radiographic changes (bone loss needs 30-50% decalcification to show on plain X-ray)
• After 10-14 days: ill-defined radiolucency, "moth-eaten" pattern
• Sequestrum (necrotic bone fragment - dense, surrounded by radiolucent halo)

1. Adequate analgesia
2. High-dose IV antibiotics (penicillin + metronidazole; or clindamycin + gentamicin) for 4-6 weeks
3. Removal of offending tooth (source)
4. Incision and drainage of any abscess
5. Sequestrectomy and saucerization for sequestra
6. Hyperbaric oxygen therapy (HBO) as adjunct
7. Correct any underlying metabolic/systemic disorders

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Chronic Suppurative Osteomyelitis

• Low-grade persistent pain
• Multiple draining sinuses (hallmark)
• Sequestra on probing sinuses
• Pathological fracture (with extensive involvement)
• Limited trismus

• Mixed radiopaque/radiolucent "moth-eaten" appearance
• Dense sequestra visible
• Involucrum (new bone formation around sequestrum)
• Periosteal new bone formation

1. Long-term antibiotics (culture & sensitivity guided) - often 3-6 months
2. Sequestrectomy - surgical removal of all necrotic bone
3. Saucerization - converting the cavity into a saucer shape for drainage and healing
4. Decortication (for diffuse disease)
5. Hemimandibulectomy if extensive and uncontrolled
6. HBO as adjunct
7. Reconstruction after infection is controlled

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Garre's Osteomyelitis (Chronic Sclerosing Osteomyelitis with Proliferative Periostitis)

• Children and young adults
• Periosteal new bone laid down in response to low-grade infection
• "Onion skin" periosteal reaction on X-ray
• Management: remove offending tooth; antibiotics; periosteal reaction regresses

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Q. Oroantral Fistula (OAF)

• Extraction of maxillary premolars and molars (especially first and second molars with long divergent roots close to sinus)
• Periapical infection breaching sinus floor
• Trauma, cysts, tumors

• Oro-nasal regurgitation of fluids
• Nasal discharge (ipsilateral)
• Nasal voice, resonance change
• Air bubbling from socket (Valsalva test positive)
• Mouth-blowing test: air comes out of nose when blowing through mouth (holding nose)

• Acute (< 24 hrs, < 2-3 mm): Primary closure with sutures + blood clot preservation; advise against nose blowing; antibiotics + decongestants
• Chronic/persistent (> 48 hrs or large): Requires surgical repair:
  1. Rehrmann's flap - buccal advancement flap (most common)
  2. Palatal rotation flap - for larger defects
  3. Buccal fat pad flap (Bichat's fat pad)
  4. Caldwell-Luc operation if chronic sinusitis present - sinus lavage + OAF repair simultaneously

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Q. Fascial Space Infections

• Boundaries: medially - medial pterygoid; laterally - ramus of mandible; anteriorly - pterygomandibular raphe; posteriorly - parotid gland
• Contents: IAN, lingual nerve, inferior alveolar vessels, sphenomandibular ligament
• Source: mandibular 3rd molar infection; IANB injection
• Signs: trismus, medially displaced tonsil/faucial pillar, pain on swallowing
• Access for drainage: intraoral vertical incision along medial border of ramus, or extraoral submandibular

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SECTION 4: ORAL PATHOLOGY

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Q. Ameloblastoma - Classification, Clinical Features, Management

1. Conventional (multicystic) ameloblastoma - most common, most aggressive locally
2. Unicystic ameloblastoma - less aggressive; subtypes: luminal, intraluminal, mural
3. Peripheral (extraosseous) ameloblastoma - arises in gingiva, rare
4. Metastasizing ameloblastoma - histologically benign but metastasizes (lung)

• Age: 30-60 years (can be any age)
• Location: 85% in mandible (most commonly molar-ramus region)
• Slow-growing, painless jaw swelling
• Buccal and lingual cortical plate expansion ("egg shell crackling" on palpation)
• Later: facial asymmetry, loose teeth, pathological fracture
• Molecular: BRAF V600E mutation in >70% of cases

• Multilocular "soap bubble" or "honeycomb" pattern (most characteristic)
• Or unilocular well-defined radiolucency
• Root resorption of adjacent teeth (knife-edge/spiking root resorption)
• Cortical bone expansion
• Associated with impacted tooth in ~15% cases

• Follicular pattern: Islands of odontogenic epithelium with peripheral tall columnar ameloblasts showing reversed nuclear polarity; central stellate reticulum
• Plexiform pattern: Anastomosing strands of epithelium
• Acanthomatous: Squamous metaplasia in cell islands
• Granular cell: Central cells have abundant granular cytoplasm
• Desmoplastic: Dense collagenous stroma
• Basal cell: Rare

• Conservative: Enucleation + curettage (for unicystic luminal/intraluminal); high recurrence ~60-80% for conventional type if treated conservatively
• Radical (preferred for conventional): Resection with 1 cm safety margin beyond radiographic extent; hemimandibulectomy or segmental resection
• Reconstruction: iliac crest bone graft, fibula free flap
• Targeted therapy: BRAF inhibitors (dabrafenib + trametinib) for recurrent/unresectable confirmed BRAF V600E mutant cases - Lippincott Pharmacology

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Q. Odontogenic Keratocyst (OKC) / KCOT

• Peak incidence: 2nd-3rd decade; more common in males
• Mandible > maxilla (3:1 ratio); most common in mandibular posterior body and ramus
• Often asymptomatic; discovered incidentally
• If symptomatic: swelling, pain, trismus, paresthesia, discharge from sinus
• May be associated with an impacted tooth
• Gorlin-Goltz syndrome (Nevoid basal cell carcinoma syndrome): Multiple OKCs + basal cell carcinomas + rib anomalies + calcification of falx cerebri

• Well-defined, corticated, scalloped radiolucency
• Unilocular or multilocular (in large lesions)
• Grows in an anteroposterior direction without expanding buccal/lingual cortex (unlike most cysts) - hallmark radiographic feature
• May cause displacement/resorption of adjacent teeth
• Bowing of inferior border of mandible (large lesions)

• Epithelial lining: 6-8 cell layers thick
• Parakeratinized surface (most characteristic - corrugated/wavy surface keratin)
• Flat epithelial-connective tissue interface (no rete ridges)
• Basal layer: palisaded, hyperchromatic columnar/cuboidal cells
• Satellite (daughter) cysts in the wall - key reason for high recurrence
• High mitotic activity

• Enucleation + Carnoy's solution (chemical cautery of cyst walls) - reduces recurrence
• Marsupialization (Partsch I) - to reduce size before enucleation, especially in children
• Enucleation alone - high recurrence (up to 62%; modern series <10% with careful curettage)
• Resection - for very large or recurrent lesions, multiple recurrences
• Adjunct: peripheral ostectomy, cryotherapy
• Recurrence rate: Up to 62.5% (high due to daughter cysts, residual epithelium, prostaglandin-mediated bone resorption)

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Q. Fibrous Dysplasia

• Monostotic (single bone - most common, ~75%)
• Polyostotic (multiple bones)
• McCune-Albright syndrome: Polyostotic fibrous dysplasia + café-au-lait skin pigmentation + precocious puberty (endocrine anomalies) - all due to GNAS1 mutation

• Age: children and adolescents (active during growth, tends to stabilize after puberty)
• Painless, progressive, unilateral jaw expansion
• Most common in maxilla > mandible
• "Orange peel" or "peau d'orange" skin texture over swelling (maxillary)
• Can cause displacement of teeth, orbital dystopia (maxillary)

• Characteristic "ground glass" opacity (most important X-ray finding)
• "Orange peel" trabecular pattern
• Ill-defined borders (blends with normal bone - "like fog over a landscape")
• Expansion of cortical bone without perforation
• Root divergence, tooth displacement

• Cellular fibrous stroma
• Woven (immature) bone trabeculae in C-, S-, or curvilinear shapes ("Chinese letters" pattern)
• No osteoblastic rimming of trabeculae (unlike ossifying fibroma)

• Conservative: observation during growth phase (active lesion)
• Surgical: Contouring/recontouring (reshaping) after skeletal maturity for aesthetic or functional deformity
• Not enucleated (no capsule - blends with normal bone)
• Denosumab (anti-RANKL) and bisphosphonates for pain control and to reduce bone turnover
• Note: Risk of malignant transformation is very low (<1%), higher with radiation (avoid RT)

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SECTION 5: FRACTURES & TRAUMA

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Q. Classification of Mandibular Fractures

• Symphysis (between canines)
• Parasymphysis (between canine and mental foramen)
• Body (between mental foramen and angle)
• Angle (from last molar to posterior attachment of masseter)
• Ramus
• Condylar process (subcondylar, condylar neck, intracapsular)
• Coronoid process
• Alveolar process

• Class 1: No displacement
• Class 2: Deviation with condyle in fossa
• Class 3: Displaced condyle outside fossa (luxation)
• Class 4: Condyle displaced medially (into middle cranial fossa)

• Simple vs. compound (open)
• Greenstick (children)
• Comminuted

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Q. Angle of Mandible Fracture - Clinical Features & Management

• Pain, swelling, tenderness at angle
• Malocclusion (posterior open bite on affected side, shift of midline toward fractured side)
• Trismus (spasm of masseter, medial pterygoid)
• Step deformity at inferior border
• Abnormal mobility of fragments
• Paresthesia of lower lip if IAN damaged
• Bruising in floor of mouth

1. ORIF (Open Reduction Internal Fixation) - gold standard for displaced/compound fractures
   • Champy's osteosynthesis - miniplate placed along the Champy's ideal lines of osteosynthesis (on the external oblique ridge for angle fractures)
   • One miniplate at superior border is sufficient for angle fractures
2. IMF (Intermaxillary fixation) - for non-displaced fractures or as temporary stabilization
   • Arch bars (Erich arch bars) with wires - most common method
   • Ernst ligatures, ivy loops
3. Antibiotics (penicillin + metronidazole) - for compound fractures
4. Extraction of tooth in fracture line if periodontally compromised or interfering with reduction

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Q. Condylar Fracture - Classification & Management

• Pain in pre-auricular region
• Anterior open bite (bilateral condylar fracture)
• Deviation of mandible to fractured side on opening (pterygoid action unopposed)
• Restricted mouth opening, trismus
• Hemarthrosis in TMJ
• Malocclusion

• IMF for 2-3 weeks followed by active physiotherapy
• Indications: undisplaced, favorable position, children (growing condyle has remodeling potential), bilateral condylar fractures, medically unfit patients

• Indications: condyle displaced into middle cranial fossa, condyle displaced into the external auditory canal, bilateral condylar fracture with anterior open bite that cannot be managed with IMF, associated midface fracture

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Q. Middle Third Facial Fractures - Le Fort Classification

• Malocclusion; mobile maxilla; "cracked teapot" sign (CSF if orbital involvement); nasal bleeding; upper lip bruising

• Bilateral periorbital ecchymosis ("raccoon eyes")
• Lengthening of face; retro-displacement of midface
• Battle's sign (if temporal bone involved)
• Diplopia, enophthalmos
• CSF rhinorrhea (dural tear)
• Subconjunctival hemorrhage

1. Airway first (nasopharyngeal airway, intubation, or tracheostomy)
2. Control hemorrhage
3. IMF to restore occlusion (reference point for reconstruction)
4. ORIF of fracture buttresses - zygomaticomaxillary, nasomaxillary, pterygomaxillary
5. Gilles temporal approach - for zygomatic complex fractures (elevator via temporal incision)
6. Timing: semi-elective within 7-10 days (before fibrosis sets in)

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Q. Zygomatic Complex Fracture

• Flattening of cheek (loss of malar prominence)
• Periorbital ecchymosis
• Unilateral epistaxis
• Paresthesia of infraorbital nerve (cheek, upper lip, lateral nose)
• Trismus (if arch depresses onto coronoid)
• Palpable step deformity at infraorbital rim or zygomaticomaxillary buttress
• Enophthalmos, diplopia (if orbital floor involved)

• Gilles temporal approach (closed): elevator inserted through temporal incision, slid beneath zygoma, elevated back into position
• Open reduction: through infraorbital/subciliary incision, intraoral maxillary vestibular incision, and/or temporal incision; plating at ZF suture and infraorbital rim

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SECTION 6: TMJ DISORDERS & FACIAL PAIN

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Q. TMJ Ankylosis - Definition, Classification, Clinical Features, Management

• True ankylosis: Intra-articular; fibrous or bony
• False ankylosis (pseudoankylosis): Extra-articular - coronoid process elongation, zygomatic arch impingement, muscle fibrosis (after radiation, burns), scarring
• By extent: Unilateral or bilateral
• By tissue: Fibrous (earlier), bony (complete ossification)

• Birth trauma (forceps delivery)
• Condylar fracture (most common cause in adults)
• Pyogenic arthritis, Rheumatoid arthritis
• Infection from adjacent structures (otitis media)
• Radiation fibrosis

• Progressive limitation of mouth opening (trismus)
• Micrognathia and "bird face" deformity (if onset in childhood - mandible fails to grow)
• Retrognathia, receding chin
• Anterior open bite (bilateral cases)
• Deviation of chin to affected side (unilateral)
• Difficulty chewing, swallowing, speech, oral hygiene
• Sleep apnea
• Radiographic: loss of joint space, bony bridge, condylar deformity

1. Aggressive resection of ankylotic mass (aggressively remove bone)
2. Ipsilateral coronoidectomy (always)
3. Contralateral coronoidectomy if mouth opening <35 mm after step 2
4. Lining of TMJ fossa with temporal fascia or cartilage
5. Reconstruction of ramus-condyle unit (costochondral rib graft in children; total TMJ prosthesis in adults)
6. Rigid fixation
7. Early mobilization and aggressive physiotherapy - most important step to prevent recurrence

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Q. Trigeminal Neuralgia (Tic Douloureux)

• Sudden, lancinating, electric shock-like pain lasting seconds
• Unilateral, follows trigeminal distribution (V2 and/or V3 most commonly; V1 rare)
• Trigger zones: light touch to lip, cheek, nasal ala, talking, eating, cold wind, washing face
• Refractory period after each attack
• Perfectly normal neurological examination between attacks
• More common in women over 50 years; right side > left
• "Tic" - facial muscle spasm may accompany pain

• Postherpetic neuralgia (follows herpes zoster distribution; burning, continuous)
• Atypical facial pain (psychological, no trigger zone)
• Dental pain (localized to tooth)
• Temporomandibular disorder (dull ache + joint clicking)
• Multiple sclerosis (bilateral, younger patients)
• Cluster headache (periorbital, autonomic features)

• Carbamazepine (drug of choice) - Na+ channel blocker; start 200 mg/day, titrate to 1200 mg/day
• Oxcarbazepine (fewer side effects than carbamazepine)
• Gabapentin, baclofen (adjuncts)

• Microvascular decompression (Janetta procedure) - gold standard for surgical treatment; removes vascular loop compressing trigeminal root; highest success, longest pain-free period
• Percutaneous procedures (for elderly/unfit):
  • Glycerol rhizolysis (injection into Meckel's cave)
  • Balloon microcompression
  • Radiofrequency thermocoagulation (electrocoagulation of Gasserian ganglion)
• Gamma knife radiosurgery - non-invasive, targets trigeminal root entry zone
• Peripheral neurectomy - avulsion of peripheral nerve branches (supraorbital, infraorbital, mental nerves); temporary relief; causes sensory deficit

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Q. TMJ Dislocation

• Open locked jaw - patient cannot close
• Preauricular hollow (condyle displaced forward)
• Bilateral: anterior open bite, protruded mandible, muscle spasm
• Drooling, difficulty swallowing

• Hippocratic method (manual reduction): Thumbs placed on lower molar teeth; downward force to disengage condyle from eminence, then backward and upward to reposition
• Pre-treatment: muscle relaxant (diazepam IV) or local anesthetic into joint space
• Post-reduction: bandage, soft diet, avoid wide opening for 2 weeks
• Recurrent dislocation: Eminectomy (surgical removal of articular eminence) - prevents condyle locking; or eminoplasty, injection of sclerosing agent, Dautrey procedure (eminence augmentation)
• Arthrocentesis - joint lavage with Ringer's lactate via two-needle technique; for hypomobility disorders and early disc displacement

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Q. Myofascial Pain Dysfunction Syndrome (MPDS / TMD)

• Most common cause of orofacial pain of non-dental origin
• Psychophysiologic disorder: stress → bruxism/parafunctional habits → muscle hyperactivity → fatigue → pain → muscle tenderness
• Cardinal signs: Unilateral preauricular/masseteric pain; limited mouth opening; clicking/crepitus; absence of organic joint pathology
• Management: reassurance, occlusal splint (Michigan splint), NSAIDs, muscle relaxants, physiotherapy, biofeedback/stress management; surgery rarely needed

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Q. Bell's Palsy

• Unilateral LMN (lower motor neuron) facial nerve palsy of unknown etiology (idiopathic); associated with HSV-1 reactivation
• Complete unilateral facial weakness including forehead (distinguishes from UMN lesion where forehead is spared)
• Lagophthalmos (inability to close eye), corneal exposure
• Bells sign: Upward rolling of eyeball on attempting to close eye (normal protective reflex; visible in Bell's palsy due to lagophthalmos)
• Management: prednisolone 1 mg/kg/day x 7-10 days (within 72 hours of onset) + antiviral (acyclovir); eye protection (lubricating drops, eye patch at night); physiotherapy

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SECTION 7: PRINCIPLES OF SURGERY (Quick Notes)

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Q. Suture Materials

• Base of flap must be broad (blood supply from base)
• Incision should not cross bony prominences
• Flap should be at least as long as wide (length:width ratio ≤ 2:1)
• Releasing incisions at corners (90° or more)
• Avoid tension on suture lines

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Q. Anaphylaxis - Management

1. Epinephrine (Adrenaline) 0.5 mg IM (1:1000) - most important, first drug
2. Position supine with legs raised
3. High-flow oxygen
4. IV access - IV fluids (crystalloids)
5. Antihistamine (chlorpheniramine 10 mg IV)
6. Corticosteroids (hydrocortisone 200 mg IV) - prevents biphasic reaction
7. CPR if cardiac arrest

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Q. CPR (Cardiopulmonary Resuscitation) - Current Guidelines (AHA 2020)

• Chain of survival: Recognition → Activate EMS → CPR → Defibrillation → Advanced care
• Compression:ventilation ratio: 30:2 (single rescuer); compression only for untrained
• Rate: 100-120 compressions/minute
• Depth: At least 5 cm (2 inches) in adults; allow full chest recoil
• Defibrillation for VF/pulseless VT - as early as possible
• "Push hard and fast, minimize interruptions"

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Q. Sterilization Methods (Quick Reference)

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Q. Hemophilia Management for Dental Extraction

1. Pre-operative hematology consultation; check factor levels and inhibitors
2. Factor replacement before procedure:
   • Hemophilia A: Factor VIII concentrate to achieve 50% activity (surgical), maintain for 5-7 days post-op
   • Hemophilia B: Factor IX concentrate
3. DDAVP (desmopressin) - mild Hemophilia A only - releases vWF and FVIII from endothelial stores
4. Antifibrinolytics: Tranexamic acid (IV or mouthwash) 10 mg/kg TID for 5-7 days - prevent clot dissolution
5. Minimize trauma, atraumatic extraction technique
6. Local hemostatic measures: oxidized cellulose (Surgicel), gelatin sponge (Gelfoam), suturing of socket
7. LA: Use infiltration (safer than blocks which risk hematoma); if IANB needed - ensure factor replacement beforehand
8. Avoid NSAIDs, aspirin (affect platelet function)
9. Post-operative monitoring in hospital

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Sources: Lippincott Illustrated Reviews: Pharmacology | ROSEN's Emergency Medicine | K.J. Lee's Essential Otolaryngology | Cummings Otolaryngology Head & Neck Surgery | Scott-Brown's Otorhinolaryngology | Roberts & Hedges' Clinical Procedures

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