DNB Otorhinolaryngology — Complete 10-Mark Answers

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Question 1

a) Labelled Diagram: Intratemporal Branches of the Facial Nerve [5 marks]

Internal Acoustic Meatus → Labyrinthine Segment
         |
    GENICULATE GANGLION
         |
    ┌────┴────────────────────────────────────┐
    │                                         │
Greater Superficial           Nerve to Stapedius
Petrosal Nerve (GSP)          (from mastoid segment)
(→ lacrimal gland,            (→ stapedius muscle)
   nasal glands)
    │                                         │
External Superficial     Chorda Tympani
Petrosal Nerve           (from mastoid segment,
(→ parotid gland)        2nd genu region)
                         (→ taste ant. 2/3 tongue,
                            submandibular & sublingual
                            gland secretion)
         |
    STYLOMASTOID FORAMEN (exits temporal bone)

• Greater Superficial Petrosal Nerve — arises at geniculate ganglion; carries preganglionic parasympathetic fibers to pterygopalatine ganglion → lacrimal, nasal, and palatal glands
• Nerve to Stapedius — arises in the mastoid segment just above the second genu; controls stapedius reflex (acoustic attenuation)
• Chorda Tympani — arises 5 mm above stylomastoid foramen; carries taste from anterior 2/3 tongue and preganglionic parasympathetic fibers to submandibular and sublingual glands via the lingual nerve

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b) Electrodiagnostic Tests and Their Significance in Facial Palsy [5 marks]

• These tests help localize the site of lesion along the facial nerve
• ENoG is the gold standard for prognosis in acute facial palsy (e.g., Bell's palsy)
• EMG is the only test that detects early reinnervation and guides timing of surgical intervention
• Serial testing helps monitor recovery or progression

a) Clinical Features of Otogenic Cerebellar Abscess [5 marks]

• Fever, headache (suboccipital or generalized)
• Nausea and vomiting (often projectile — due to raised ICP)
• Neck stiffness (meningism if meninges involved)

• Ataxia — broad-based, staggering gait; falls to the side of the lesion
• Intention tremor — finger-nose test positive
• Dysdiadochokinesia — impaired rapid alternating movements
• Dysmetria — past-pointing (Holmes rebound test positive)
• Nystagmus — coarse, horizontal; fast phase away from lesion (contralateral)
• Hypotonia — decreased muscle tone ipsilaterally
• Dysarthria — scanning or staccato speech

• Papilloedema
• Bradycardia with hypertension (Cushing's triad)
• Altered consciousness in late stages

• Ear discharge (often foul-smelling, cholesteatoma)
• Perforation of tympanic membrane
• Features of mastoiditis

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b) Management of Otogenic Cerebellar Abscess [5 marks]

• Airway, breathing, circulation
• IV antibiotics: high-dose broad-spectrum (e.g., Ceftriaxone + Metronidazole + Vancomycin)
• IV dexamethasone — reduces cerebral edema
• IV mannitol (20%) — for raised ICP

• Contrast-enhanced CT scan of brain and temporal bones — first-line; shows ring-enhancing lesion, mass effect, midline shift
• MRI brain — superior for posterior fossa; DWI confirms abscess

• Aspiration is preferred if abscess is accessible — less morbid, can be repeated
• Pus sent for Gram stain, culture and sensitivity

• Mastoidectomy (cortical or modified radical) — to eliminate the source of infection
• Done simultaneously or after neurosurgical drainage, once patient is stable
• Removal of cholesteatoma is essential to prevent recurrence

• Continue targeted antibiotics for 4–6 weeks
• Serial CT scans to monitor resolution
• Physiotherapy for cerebellar deficits
• Prognosis: Mortality ~10%; significant morbidity if delayed

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Question 3

a) Clinical Examination for Spontaneous Nystagmus in OPD [2 marks]

1. Naked eye observation — Observe gaze in primary position first
2. Frenzel glasses (+20 diopter lenses) — removes fixation suppression; best tool in OPD; illuminate eye from sides
3. Gaze testing — Test in five positions: primary, right, left, up, down; note direction (by convention, direction of fast phase)
4. Alexander's law — Nystagmus increases in intensity when looking in the direction of the fast phase; helps identify peripheral vs central
5. Fixation test — Spontaneous peripheral nystagmus is suppressed by fixation; central nystagmus is not

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b) Central vs Peripheral Nystagmus [5 marks]

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c) Grades of Nystagmus (Bárány/Alexander's Classification) [3 marks]

• Grade I (Mild): Nystagmus present only when looking in the direction of the fast phase
• Grade II (Moderate): Nystagmus present in the primary (straight ahead) position and when looking in the direction of the fast phase
• Grade III (Severe): Nystagmus present in all positions of gaze, including when looking in the direction of the slow phase

a) Definition of Otosclerosis [1 mark]

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b) Clinical Features and Audiological Evaluation [3 marks]

• Predominantly affects young white females (F:M = 2:1); bilateral in 70–80%
• Insidious, progressive conductive hearing loss — begins in second or third decade
• Paracusis Willisii — paradoxical improvement of hearing in noisy environments (background noise stimulates others to speak louder)
• Tinnitus — low-frequency; in 75% of patients
• No history of ear discharge, earache, or prior ear surgery
• Normal-looking tympanic membrane (cardinal sign)
• Schwartze sign (Flamingo pink sign) — reddish blush through the tympanic membrane from vascular active bone over promontory; present in ~10%, indicates active disease
• Speech is soft (patient speaks softly because bone conduction is intact — autophony)

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c) Fenestration of Stapes Footplate: Methods and Advantages of LASER [2 marks]

1. Mechanical perforator (Fisch perforator) — traditional hand instrument
2. Microdrill (Skeeter drill) — rotating drill bit; risk of heat damage
3. Laser fenestration — current gold standard

• CO₂ laser, KTP (potassium titanyl phosphate) laser, Erbium:YAG laser

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d) Complications of Stapedectomy [4 marks]

• Floating footplate — entire footplate sinks into vestibule; occurs due to excessive pressure; requires specialized floating footplate techniques
• Perilymph gusher — profuse perilymph flow; associated with X-linked stapes gusher (DFNX2); risk of SNHL; manage by sealing with fat/fascia
• Footplate fracture / saucerization — irregular fracture; use micro-pick/laser to complete
• Facial nerve injury — if nerve dehiscent or anomalously placed
• Tympanic membrane tear

• Vertigo and nausea — transient; due to perilymph disturbance; usually resolves in 48 hours
• Sensorineural hearing loss (SNHL) — partial or total; most feared complication; due to perilymph contamination, prosthesis displacement, or labyrinthine damage
• Perilymph fistula — leak around prosthesis/stapedotomy hole; causes fluctuant hearing + vertigo
• Tympanic membrane perforation

• Prosthesis displacement/extrusion — slippage from long process of incus; causes recurrent CHL
• Incus necrosis — avascular necrosis of long process; due to mechanical pressure of prosthesis
• Reparative granuloma — foreign body reaction; presents at 2–6 weeks; severe SNHL + vertigo; rare but serious; requires immediate exploration
• Recurrent conductive loss — due to prosthesis dislodgement or regrowth of otosclerotic focus
• Dead ear (total SNHL) — worst outcome; 1–2% risk with experienced surgeons

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Question 5

a) Impedance Audiometry Curves and Clinical Significance [5 marks]

• Diagnose middle ear effusion (Type B with small ear canal volume)
• Detect TM perforations (Type B with large ear canal volume)
• Identify ossicular chain pathology
• Confirm eustachian tube dysfunction

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b) Stenger's Principle [2 marks]

• Based on the phenomenon of binaural suppression — the louder stimulus dominates conscious perception
• Applied in the Stenger test to detect unilateral non-organic (functional) hearing loss
• If a pure tone is presented to the good ear at a soft level (just above threshold) and to the "bad" ear at a louder level (but below the claimed threshold), a malingerer will not respond (because they hear only the louder tone in the "bad" ear but will pretend not to, revealing the deception)
• A genuinely deaf person in the bad ear will respond (they only hear the tone in the good ear)
• Positive Stenger test = malingering confirmed

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c) Clinical and Audiological Tests to Establish Malingering [3 marks]

• Lombard test (Voice reflex test): Subject reads aloud; masking noise fed into both ears; a true hearing individual unconsciously raises their voice (Lombard effect). A malingerer pretends not to hear but raises their voice, confirming hearing.
• Delayed Auditory Feedback (DAF): When speaking is delayed and replayed; true hearing subjects stutter/slow speech. Malingerer shows no response to noise they claim not to hear.

a) Differentiate Between Case-Control and Cohort Study [4 marks]

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b) Odds Ratio and Relative Risk [4 marks]

• Used in cohort studies
• Ratio of the incidence of disease in the exposed group to the incidence in the unexposed group

RR = [A/(A+B)] / [C/(C+D)]

• RR = 1: No association
• RR > 1: Exposure increases risk (positive association)
• RR < 1: Exposure is protective
• More intuitive; directly estimates risk

• Used in case-control studies (incidence unknown)
• Ratio of the odds of exposure in cases to the odds of exposure in controls

OR = (A/C) / (B/D) = (A×D) / (B×C)

• When disease is rare (< 10% prevalence), OR approximates RR
• OR = 1: No association; OR > 1: Increased odds; OR < 1: Reduced odds
• Also used in logistic regression, meta-analyses

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c) Impact Factor and Its Relevance [2 marks]

IF (2023) = Citations in 2023 to articles published in 2021 + 2022 / Total articles published in 2021 + 2022

• Indicates the relative importance and influence of a journal within its field
• Used by researchers and institutions to assess journal quality when choosing where to submit work
• Used in academic promotions and tenure decisions to evaluate productivity
• High IF journals (e.g., NEJM ~100, Lancet ~200) carry more academic prestige
• Limitations: Varies by specialty (surgery journals have lower IF than medicine); prone to citation manipulation; doesn't reflect individual article quality; recently supplemented by h-index, Altmetric scores, and CiteScore

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Question 7

a) Composition of Endolymph and Perilymph [2 marks]

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b) Etiological Factors for Primary Endolymphatic Hydrops [3 marks]

1. Impaired endolymph reabsorption — dysfunction of the endolymphatic sac (ES); ES is responsible for reabsorption and immune defense
2. Increased endolymph production — stria vascularis hyperactivity
3. Obstruction of endolymphatic duct — anatomical narrowing of vestibular aqueduct (narrow vestibular aqueduct seen in Meniere's on HRCT)
4. Autoimmune factors — anti-68 kDa heat shock protein antibodies; autoimmune inner ear disease can mimic Meniere's; HLA-B44 association
5. Viral etiology — prior viral labyrinthitis (HSV-1 in endolymphatic sac tissue)
6. Genetic predisposition — familial Meniere's (5–15%); COCH gene mutations
7. Allergy and dietary factors — high-salt diet, caffeine, alcohol precipitate attacks
8. Vascular/ischemic factors — endolymphatic sac ischemia

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c) Surgical Modalities for Managing Meniere's Disease [5 marks]

• Labyrinthectomy: 95–98%
• Vestibular neurectomy: 90–95%
• ESD: 70–80%
• IT gentamicin: 80–90%

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Question 8

a) Acoustic Reflex Pathway (with schematic) [4 marks]

SOUND (loud, >70-90 dB SPL)
        ↓
Cochlea (hair cells → cochlear nerve CN VIII)
        ↓
Cochlear nuclei (dorsal + ventral) — brainstem
        ↓
Superior Olivary Complex (bilateral projection)
        ↓
Facial nerve nuclei (BILATERAL — ipsilateral + contralateral)
        ↓
Facial nerve (CN VII) — both sides
        ↓
Stapedius muscle contraction (BILATERAL)

• Reflex is bilateral regardless of which ear is stimulated → ipsilateral (same ear) and contralateral (opposite ear) reflexes
• Afferent: CN VIII (cochlear nerve)
• Efferent: CN VII (facial nerve)
• Reflex arc goes through brainstem (superior olivary complex/trapezoid body)
• Purpose: Attenuates low-frequency sounds, protects cochlea from sustained loud noise, improves signal-to-noise for speech

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b) Acoustic Reflex Decay Test — Principle and Application [3 marks]

• The stapedius muscle normally sustains contraction at 10 dB above reflex threshold for ≥10 seconds
• In retrocochlear pathology (e.g., acoustic neuroma / vestibular schwannoma), the reflex decays (fades) rapidly due to adaptation/fatigue of CN VIII fibers
• Stimulus is sustained at 500 Hz and 1000 Hz at 10 dB above ARTh for 10 seconds

• Normal (negative decay): Compliance returns to < 50% of initial amplitude after 10 seconds (or no significant decay)
• Abnormal (positive decay): Amplitude decreases by ≥ 50% within 5 seconds → suggests retrocochlear lesion

• Screening tool for acoustic neuroma / vestibular schwannoma
• Part of the audiological battery alongside ABR for detecting retrocochlear pathology
• Sensitivity ~50–70%; ABR is superior but decay is a quick, non-invasive screening step

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c) Diagnostic Applications of Acoustic Reflex [3 marks]

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Question 9

a) Limitations and Fallacies of Pure Tone Audiometry [6 marks]

• Results are entirely dependent on patient's conscious, voluntary responses
• Cannot be used reliably in young children (< 5 years), unconscious or cognitively impaired patients
• Susceptible to malingering / pseudohypacusis

• Tests at 250, 500, 1000, 2000, 4000, 8000 Hz — misses inter-octave changes
• High-frequency hearing (above 8000 Hz) not routinely tested — early ototoxicity missed

• Does not predict functional communication ability — needs additional speech audiometry

• Sound can cross to the better ear (interaural attenuation ~40 dB for AC, ~10 dB for BC)
• Without masking → shadow curve errors; over-masking and under-masking are pitfalls
• Masking dilemma — when both ears have severe BC loss, adequate masking is impossible without over-masking

• Dip at 2000 Hz in BC audiogram in otosclerosis (mechanical resonance artifact)
• May falsely suggest SNHL component — improves after stapedectomy

• Cannot differentiate cochlear from retrocochlear SNHL without additional tests (ABR, OAE)

• Normal variability ±5–10 dB; errors in threshold determination

• Same audiogram pattern can result from different pathologies (e.g., noise-induced SNHL vs gentamicin toxicity both show 4000 Hz notch)

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b) Pathways of Bone Conduction [4 marks]

• Vibrating skull → vibration of ear canal walls → sets tympanic membrane in motion → ossicular chain → oval window
• Most significant at low frequencies
• This is why occlusion of the ear canal (Bing test, occlusion effect) increases BC thresholds for low frequencies

• Skull vibrates → ossicular chain lags behind due to inertia of ossicles (especially malleus/incus)
• Creates relative movement between footplate and oval window → fluid stimulation
• Most significant at mid-frequencies (~1000 Hz)

• Skull vibration → alternating compression and expansion of the cochlear capsule itself
• Creates differential fluid movements within scala vestibuli and scala tympani (due to asymmetrical compliance of round vs oval window)
• Most significant at high frequencies

• Inertial lag of cochlear fluids themselves due to skull vibration
• Minor contribution

• Vibration of soft tissue walls of ear canal
• Part of the Occlusion Effect

• Occlusion effect (BC improves when canal occluded) — due to enhanced osseotympanic pathway; used in Bing test and Weber test
• Carhart's notch — loss of inertial BC at 2000 Hz in otosclerosis (stapes fixation abolishes inertial pathway)
• Air-bone gap — reflects middle ear contribution; important in surgical planning

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Question 10

a) Definition of Otic Barotrauma [1 mark]

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b) Differences Between Inner Ear Barotrauma and Inner Ear Decompression Illness [4 marks]

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c) Management of Barotrauma-Induced Perilymphatic Fistula [5 marks]

• Strict bed rest with head elevation (30°) for 5–7 days
• Avoid all pressure-raising activities: Valsalva, nose blowing, straining, heavy lifting, coughing, constipation
• Avoid strenuous activity and air travel
• Stool softeners — to prevent straining
• Analgesics and antiemetics
• Avoid aspirin/NSAIDs (theoretical risk of perilymph pressure alteration)
• Serial audiogram monitoring — improvement in SNHL suggests spontaneous closure

• No improvement in SNHL or vertigo after 4–6 weeks conservative management
• Worsening SNHL
• Severe incapacitating vertigo
• Confirmed or suspected round/oval window membrane rupture

• Exploratory tympanotomy under local or general anesthesia
• Inspect round window niche, oval window, and annular ligament for perilymph leak
• Confirmation: perilymph gusher or pooling in niche; beta-2 transferrin assay of fluid
• Patch/seal with fat, connective tissue (perichondrium, fascia), or fibrin glue
• Round window reinforcement and oval window sealing
• Stapedial footplate check if oval window fistula

• Continue activity restriction for 2 weeks
• Avoid flying for 4 weeks
• Monitor hearing and vestibular function

• Vertigo improves in >80% after surgical repair
• SNHL recovery is variable — early intervention gives better hearing outcomes
• Risk of recurrence if activity restrictions are not followed

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Summary Index

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• In Q1, draw the facial nerve geniculate ganglion diagram with all three intratemporal branches clearly labeled with their functions — examiners reward well-drawn, labeled diagrams
• In Q4, always mention Carhart's notch by name and explain it as a mechanical artifact not true SNHL
• In Q6, write the 2×2 table clearly with the OR and RR formulas — it scores well
• In Q9, the "fallacies" section distinguishes a 6-mark answer from a basic 4-mark one

DNB Otorhinolaryngology ENT Paper 2 — Complete 10-Mark Answers

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Question 1

a) Aetiological Factors for Nasal Septal Perforation [3 marks]

• Septal surgery (SMR/septoplasty) — most common cause; bilateral mucosal tears at same level
• Nasal cauterization (bilateral simultaneous cautery)
• Nasal packing (pressure necrosis)
• Nasogastric tube trauma
• Nose picking (digital trauma) — anterior perforations

• Syphilis (tertiary) — large posterior perforations; destroys cartilage and bone
• Tuberculosis — painless, irregular edges
• Leprosy
• Rhinoscleroma
• Fungal infections (mucormycosis, aspergillosis)

• Granulomatosis with polyangiitis (Wegener's) — classic cause; saddle nose deformity
• Sarcoidosis
• Lupus erythematosus

• Chromic acid fumes (chrome platers) — classic occupational cause
• Arsenic, mercury, phosphorus exposure
• Cocaine abuse (vasospasm + direct toxicity) — important modern cause; anterior cartilaginous septum

• Squamous cell carcinoma
• T-cell lymphoma (lethal midline granuloma / NK/T-cell lymphoma)

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b) Clinical Features of Septal Perforation [2 marks]

• Crusting and epistaxis — most common; turbulent airflow desiccates mucosa
• Whistling sound on nasal breathing — small anterior perforations (classic)
• Nasal obstruction — paradoxically, air turbulence causes sensation of blockage
• Nasal discharge — mucopurulent; crust accumulation
• Painful ulceration — if active granulomatous disease
• Saddle nose deformity — if cartilaginous support lost (syphilis, Wegener's, cocaine)

• Anterior rhinoscopy / nasal endoscopy reveals perforation location and size
• Edges: smooth and epithelialized (old) vs irregular and crusted (active)
• Small perforations (< 1 cm) cause whistling; large perforations are often asymptomatic

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c) Management Options for Nasal Septal Perforation [5 marks]

• Nasal saline irrigation (twice daily) — softens crusts, moisturizes mucosa
• Nasal emollients (petroleum jelly, sesame oil) — prevents desiccation
• Antibiotic ointment — if secondary infection
• Septal button (obturator): Silastic prosthesis inserted into perforation; button with two flanges on either side; reduces symptoms; for patients unfit for surgery or large perforations; may extrude

• Treat underlying cause first (stop cocaine, treat Wegener's, etc.)
• Closure success rate: 70–90% for small perforations; decreases with size
• Three-layer closure (bilateral mucosa + cartilage graft) gives best results

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Question 2

a) Haller Cell and Onodi Cell — Definition and Clinical Relevance [3 marks]

• An ethmoidal air cell that pneumatizes below the orbital floor (inferior to the orbital plate), lying adjacent to or within the maxillary sinus ostium
• Named after Albrecht von Haller
• Seen on coronal CT as a cell below the medial orbital wall / lateral to the infundibulum

• Can narrow the ethmoidal infundibulum and obstruct the maxillary sinus ostium → recurrent maxillary sinusitis
• Must be identified and opened during FESS to adequately widen the ostium
• Failure to recognize → persistent maxillary sinusitis post-FESS

• A posterior ethmoidal air cell that pneumatizes laterally and posteriorly into the sphenoid bone, lying superior or superolateral to the sphenoid sinus
• The optic nerve and internal carotid artery may run through or adjacent to the Onodi cell — sometimes with thin or absent bony walls

• High risk of optic nerve injury and ICA injury during posterior ethmoidectomy if not recognized
• Must be identified preoperatively on axial + coronal CT before FESS
• Sinusitis in an Onodi cell can cause optic neuritis due to proximity
• Mistaking it for the sphenoid sinus and proceeding can be catastrophic

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b) Attachments of the Uncinate Process [3 marks]

• Anterior: Attaches to the lacrimal bone and frontal process of maxilla
• Inferior: Attaches to the inferior turbinate (ethmoidal process of inferior turbinate)
• Superior (variable — 3 types, determines frontal sinus drainage):

• The superior attachment determines where the frontal recess drains
• Uncinectomy (removal of uncinate) is the first step in FESS (after middle meatal antrostomy)
• Care must be taken superiorly to avoid skull base/orbital injury depending on attachment type

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c) Ligation Techniques for Management of Epistaxis [4 marks]

• Anterosuperior: Anterior and posterior ethmoidal arteries (from ophthalmic artery → ICA)
• Posteroinferior: Sphenopalatine artery (from maxillary artery → ECA)

• Most commonly performed; controls posterior epistaxis
• Endoscopic identification of sphenopalatine foramen (posterior to posterior attachment of middle turbinate)
• Artery clipped with metallic clips or cauterized just as it exits/enters the foramen
• Success rate: 90–98%
• Advantage: minimally invasive, low morbidity

• Lynch incision (medial orbital) or endoscopic approach
• AEA runs in a mesentery (~40% of cases) from the orbital roof — visible endoscopically
• Clipped or cauterized in the frontoethmoidal suture line
• Indicated for superior/posterior epistaxis refractory to SPA ligation

• Sublabial incision → anterior maxillary wall → posterior wall of maxillary sinus → pterygopalatine fossa → IMAX identified and clipped
• Largely replaced by endoscopic SPA ligation
• Higher morbidity (cheek numbness, dental complications)

• Neck dissection to ligate ECA below the origin of facial artery
• Reserved for life-threatening hemorrhage when other methods fail
• Collateral filling from ICA limits effectiveness

• Angiography + selective embolization of SPA or IMAX with coils/particles
• Used when surgical risk is high; success rate ~80–90%
• Risk: facial nerve palsy, stroke, visual loss (rare)

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Question 3

a) Causes of CSF Rhinorrhoea [3 marks]

• Accidental trauma — anterior skull base fractures (cribriform plate, fovea ethmoidalis, posterior wall frontal sinus)
• Iatrogenic (post-surgical) — FESS, endoscopic skull base surgery, transsphenoidal hypophysectomy, septoplasty, rhinoplasty

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b) Investigations to Establish Presence and Site of CSF Leak [4 marks]

• Beta-2 transferrin (β₂-transferrin): Gold standard; specific marker for CSF (not present in nasal secretions, tears, or serum); electrophoresis of nasal fluid; sensitivity ~90%, specificity ~100%
• Beta-trace protein (prostaglandin D synthase): Newer marker; higher sensitivity; present in CSF but not nasal mucus

• Nasal fluid glucose > 30 mg/dL — unreliable; false positives with blood/secretions; no longer recommended

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c) Surgical Approaches for Management of CSF Rhinorrhoea [3 marks]

• Bed rest with head elevation, avoid Valsalva, stool softeners, lumbar drain

• Most widely used; avoids craniotomy
• Defect identified using intraoperative intrathecal fluorescein
• Multi-layer repair: fat + fascial graft (free) + mucoperichondrial flap + fibrin glue
• Success rate: 90–95% for primary repair
• Preferred for anterior skull base (cribriform, fovea, sphenoid)

• Bifrontal craniotomy; raises dural flap to identify defect from intradural/extradural side
• For large, complex or failed endoscopic repairs
• Higher morbidity (anosmia, CSF leak, meningitis risk)

• For extensive defects or tumour-related leaks
• Neurosurgeon + ENT surgeon simultaneously

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Question 4

a) Labelled Diagram: Nasal Septum and Blood Supply [2+2 marks]

                NASAL SEPTUM
        ┌──────────────────────────┐
        │  BONY PART (posterior)   │
        │  ┌────────────────────┐  │
        │  │ Perpendicular plate│  │
        │  │ of ethmoid         │  │← Superior-posterior
        │  │ (superoposterior)  │  │
        │  ├────────────────────┤  │
        │  │ Vomer              │  │← Inferior-posterior
        │  │ (posteroinferior)  │  │
        │  └────────────────────┘  │
        │  CARTILAGINOUS (anterior)│
        │  ┌────────────────────┐  │
        │  │ Quadrilateral      │  │← Main anterior support
        │  │ (Septal) cartilage │  │
        │  └────────────────────┘  │
        │  MEMBRANOUS              │
        │  Columella (skin + soft  │← Mobile anterior-inferior
        │  tissue, no cartilage)   │
        └──────────────────────────┘

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b) Classification of Nasal Fractures and Clinical Features [3 marks]

• Pain and tenderness over nasal bones
• Swelling and oedema — may obscure deformity initially (assess at 5–7 days)
• Epistaxis — common
• Nasal deformity — lateral deviation, saddle nose, broadening
• Crepitus on palpation
• Nasal obstruction — septal deviation, haematoma, mucosal swelling
• Septal haematoma — boggy fluctuant bilateral swelling of septum; must be drained urgently (risk of cartilage necrosis → saddle nose)
• Periorbital ecchymosis (bilateral "raccoon eyes" if NOE involved)
• CSF rhinorrhoea — if cribriform plate involved (high-energy trauma)

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c) Le Fort Classification of Mid-Facial Fractures [3 marks]

• Fracture line runs horizontally above the teeth through the lower maxilla
• Separates the hard palate and lower alveolus from the upper face
• Involves: lower maxillary sinus walls, nasal floor, lower nasal septum, pterygoid plates (lower third)
• Clinical: mobile upper alveolus + teeth block; step deformity; epistaxis

• Pyramidal fracture involving the central mid-face
• Fracture line: nasofrontal junction → medial orbital wall → infraorbital rim → maxillary sinus → pterygoid plates
• Involves: nasal bones, lacrimal bones, orbital floors, zygomaticomaxillary suture
• Clinical: mobile central face ("central block" moves independently); subconjunctival haemorrhage; infraorbital hypoaesthesia; CSF rhinorrhoea possible

• Complete separation of the entire facial skeleton from the skull base
• Fracture line: nasofrontal suture → orbital walls (medial + lateral) → zygomatic arch → pterygoid plates (full height)
• Involves: frontzygomatic sutures bilaterally, zygomatic arches
• Clinical: "dishface deformity" (elongated flat face); bilateral periorbital ecchymosis; CSF rhinorrhoea; traumatic telecanthus; severe malocclusion; airway compromise

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Question 5

a) Neurovascular Relations of the Sphenoid Sinus (Labelled Diagram) [4 marks]

                    SUPERIOR
              Pituitary gland (sella turcica)
              Optic chiasma
              Anterior cranial fossa
                         |
LATERAL ─────────────────┼──────────────── LATERAL
Cavernous sinus          │        Cavernous sinus
containing:              │        containing:
• ICA (parasellar)        │        • ICA
• CN III (oculomotor)    │        • CN III
• CN IV (trochlear)      │        • CN IV
• CN V1 (ophthalmic)     │        • CN V1
• CN VI (abducens)       │        • CN VI
• CN V2 (maxillary)      │        • CN V2
(in lateral wall)        │        (lateral wall)
                         │
Optic nerve (CN II) ─────┤──────── Optic nerve (CN II)
(in optic canal,         │        (opposite side)
lateral to ICA)          │
                         │
                    POSTERIOR
              Basilar artery
              Brainstem / pons
                    INFERIOR
              Nasopharynx
              Vidian (pterygoid) canal
              (contains Vidian nerve — greater petrosal + deep petrosal)

• Optic nerve bulges into the superolateral wall (dehiscent in 4–8%)
• ICA bulges into the lateral wall (dehiscent in 20–25%)
• Opticocarotid recess between them is a landmark
• Maxillary nerve (V2) in the lower lateral wall

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b) Pneumatization Patterns of the Sphenoid Sinus [4 marks]

• Lateral recess — pneumatization extends into the greater wing of sphenoid (pterygopalatine fossa, foramen rotundum area); risk of injury to V2, pterygoid canal
• Onodi cells — posterior ethmoidal cells overlie the sphenoid; optic nerve risk
• Asymmetric pneumatization — inter-sinus septum deviates; important during pituitary surgery (don't follow septum blindly to midline)

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c) Boundaries of the Frontal Recess [2 marks]

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Question 6

a) Extrinsic Muscles of the Tongue and Their Actions [4 marks]

• CN XII lesion (unilateral) → tongue deviates toward the paralysed side on protrusion (genioglossus on normal side pushes tongue to paralysed side)
• Palatoglossus is the only tongue muscle not supplied by CN XII

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b) TNM Classification for Carcinoma of the Tongue [3 marks]

• M0: No distant metastasis
• M1: Distant metastasis (lung most common)

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c) Risk Factors for Oral Carcinomas [3 marks]

• Smoked tobacco (cigarettes, beedis, pipes): Most important; dose-dependent risk
• Smokeless tobacco (gutka, khaini, snuff): Buccal mucosa and gingival carcinoma
• Reverse smoking (chutta in South India): Hard palate carcinoma

• Independent risk factor; synergistic with tobacco (combined risk = multiplicative, not additive)
• Acetaldehyde is the carcinogenic metabolite

• Chewed alone or with tobacco (pan, gutka)
• Causes oral submucous fibrosis (OSF) — premalignant; arecoline is carcinogenic
• Especially significant in South/Southeast Asian populations

• HPV 16 and 18 — more relevant in oropharyngeal (tonsil, base of tongue) cancer; less so in oral cavity
• HPV-positive tumours have better prognosis

• Ill-fitting dentures, sharp teeth, chronic leukoplakia/erythroplakia

• Leukoplakia (5–17% malignant transformation), erythroplakia (up to 51%), oral submucous fibrosis (7–13%), lichen planus (erosive)

• Immunosuppression (post-transplant), iron deficiency (Plummer-Vinson syndrome → post-cricoid carcinoma), solar radiation (lip carcinoma), poor oral hygiene, nutritional deficiencies (vitamins A, C)

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Question 7

a) Definition of Atrophic Rhinitis [1 mark]

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b) Clinical Features of Atrophic Rhinitis [5 marks]

• Anosmia (or hyposmia) — paradoxical; patient cannot smell their own odour
• Foetor (ozaena) — fetid smell; caused by anaerobic degradation of crusts; offensive to others but not to the patient
• Nasal obstruction — despite wide nasal cavity; due to lack of normal turbulence and air sensation
• Epistaxis — from crust removal; friable mucosa
• Nasal discharge — thick, greenish-yellow, adherent crusts
• Headache — from dryness and secondary sinusitis
• Crusting — large brown/green crusts filling the nasal cavity
• Whistling on breathing in early stages
• Depression and social withdrawal due to foetor

• Wide nasal cavity — lateral wall far from septum; inferior turbinate small or absent
• Pale, dry, glazed mucosa — atrophic, thin
• Thick green-brown crusts covering turbinates, floor, posterior choana
• Greenish-yellow discharge — mucopurulent on crusts
• Pharynx and larynx may show crust extension (atrophic pharyngitis, laryngitis)
• Perforation of septum in advanced cases

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c) Treatment Modalities for Atrophic Rhinitis [4 marks]

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Question 8

a) Nasofrontal and Nasolabial Angles — Normal Ranges [3 marks]

NASOFRONTAL ANGLE:
Formed by intersection of:
• Glabella-to-nasion line (forehead slope)
• Nasion-to-tip line (nasal dorsum)
Normal range: 115°–135° (females: higher end; males: lower end)
Ideal: ~120° in males, ~130–135° in females

NASOLABIAL ANGLE:
Formed by intersection of:
• A line through the columellar base
• A line along the upper lip philtrum / labiale superius
Normal range: 90°–120° (males: 90°–95°; females: 100°–110°)
Ideal female: 105°–110°

• Decreased nasofrontal angle (< 115°) → prominent, high nasal dorsum / hump; treated with hump reduction
• Increased nasofrontal angle (> 135°) → flat dorsum, saddle nose appearance
• Decreased nasolabial angle (< 90°) → over-projected, drooping nasal tip; needs tip rotation
• Increased nasolabial angle (> 120°) → over-rotated, short nose (piggy appearance); needs derotation

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b) Incisions Used in Rhinoplasty [3 marks]

• Transcolumellar incision — inverted-V (stair-step) incision across the narrowest part of the columella (at mid-columella or infra-columellar)
• Combined with bilateral marginal (rim) incisions → columellar flap elevated → full exposure of tip and dorsum
• Superior visualization; preferred for complex tip surgery, revision rhinoplasty, cleft lip nose

• Alar base incision (Webster modification) — for alar base reduction
• Killian's incision — for septoplasty (between septal cartilage and mucoperichondrium); different from rhinoplasty
• Inter-crural incision — between medial crura of lower lateral cartilage

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c) Treatment Options for Nasal Valve Collapse [4 marks]

• External nasal valve = alar rim, nostril aperture (vestibule)
• Internal nasal valve = angle between upper lateral cartilage and nasal septum (normal: 10°–15°)

• Weak lower lateral cartilages, over-resection in rhinoplasty, aging, trauma

• Breathe Right nasal strips (external nasal dilator strips) — temporary; useful diagnostically (positive Cottle test response predicts surgical success)
• CPAP — if associated with sleep apnoea
• Nasal dilators (internal) — stents placed in vestibule

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Question 9

a) Clinical Features and Classifications of Carcinoma Maxilla [7 marks]

• Unilateral nasal obstruction
• Unilateral blood-stained nasal discharge
• Facial pain / toothache (upper premolars / molars)

• Submandibular and upper deep cervical nodes (level I and II)
• Retropharyngeal nodes
• Late involvement (10–15% at presentation)

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• Line from medial canthus of eye to angle of mandible (Ohngren's line)
• Superomedial (infrastructure + superstructure): Above Ohngren's line → worse prognosis (near orbit, skull base, pterygoids)
• Anteroinferior (infrastructure): Below Ohngren's line → better prognosis (teeth, palate, cheek — more accessible)

• Infrastructure: Below a line through floor of antrum (hard palate, alveolus, dental)
• Mesostructure: Between floor and roof of antrum (antrum proper)
• Superstructure: Above roof of antrum (ethmoids, orbit)

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b) Management Protocol for Carcinoma Maxilla [3 marks]

• Biopsy (transnasal endoscopic or Caldwell-Luc)
• CECT face + neck; MRI skull base; PET-CT for staging
• Dental evaluation; fitting of prosthetic obturator

• Post-operative radiotherapy (60–66 Gy) — standard for all T3/T4 or positive margins
• Pre-operative radiation: less common
• IMRT preferred to spare orbit and parotid

• Concurrent cisplatin-based chemotherapy with radiation for high-risk features
• Palliative chemotherapy for unresectable/metastatic disease

• Prosthetic obturator (immediate) — covers palatal defect; enables feeding
• Free flap reconstruction (radial forearm, fibula, rectus abdominis) — for large defects

• 5-year survival: T1–T2: 60–70%; T3–T4: 25–40%; nodal disease: 15–25%

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Question 10

a) Theories for Salivary Gland Neoplasms [3 marks]

• All salivary gland tumours arise from two types of reserve (stem) cells:
  • Excretory duct reserve cells → give rise to epidermoid/squamous cell elements and mucous cells
  • Intercalated duct reserve cells → give rise to acinar cells, myoepithelial cells, and intercalated duct cells
• Explains pleomorphic adenoma (myoepithelial + ductal) and mucoepidermoid carcinoma

• Different tumour types arise from differentiation of specific mature cell types
• Acinic cell carcinoma → from acinar cells
• Oncocytoma → from striated duct cells
• Mucoepidermoid carcinoma → from excretory duct cells
• Adenoid cystic carcinoma → from intercalated duct + myoepithelial cells

• Single pluripotent stem cell type in the intercalated duct region
• Simplification of Batsakis's theory

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b) TNM Classification of Parotid Gland Carcinomas [4 marks]

• M0: None; M1: Present (lung, bone, liver)

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c) Risk Factors for Salivary Gland Carcinomas [3 marks]

• Most established risk factor; ionizing radiation (prior radiotherapy to head and neck, fallout from atomic bombs — Hiroshima/Nagasaki survivors)
• Linear dose-response; latency 10–20 years
• Mucoepidermoid carcinoma and Warthin's tumour especially linked

• Rubber manufacturing, plumbing, asbestos, woodworking, nickel compounds
• Hairdressers (chronic hair spray inhalation)

• Epstein-Barr virus (EBV) — associated with lymphoepithelial carcinoma (especially in Inuit/Asian populations) and undifferentiated carcinoma
• HIV — parotid lymphoepithelial lesions (benign cysts but increased lymphoma risk)
• HPV — some mucoepidermoid carcinomas

• Associated with Warthin's tumour (papillary cystadenoma lymphomatosum) — benign but risk marker
• Weak association with malignant transformation

• Controversial; some studies suggest increased parotid gland tumour risk with heavy ipsilateral use; not definitively established

• Low fruit/vegetable intake; high animal fat
• Iodine deficiency (thyroid tumours more so, but some salivary data)

• Pleomorphic adenoma — carcinoma ex pleomorphic adenoma (3–6% malignant transformation over decades, rising to 10% after 15 years)

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Summary Index — Paper 2