Oro-Antral Fistula — ORE Part 1 MCQ
Instant feedback + full explanation. One question, done properly.
Educational content. Not a substitute for clinical judgement or local policy.
Reveal the answer and explanation
Correct answer: B — Oro-antral fistula
Explanation lettering: D = shown as A · A = shown as B · E = shown as C · B = shown as D · C = shown as E
Oro-antral fistula is the correct diagnosis. The clinical triad—extraction of an upper molar (upper second molar has roots in close proximity to the maxillary sinus), a 3-week post-operative interval, and the dual hallmark symptoms of persistent bad taste and nasal regurgitation of fluids—is pathognomonic. Oro-antral communication becomes a true fistula (epithelialized and patent) 48–72 hours after perforation; by 3 weeks, this process is complete. The nasal regurgitation occurs because liquids consumed orally can pass directly from the oral cavity into the maxillary antrum and out through the nose. Option D (oronasal fistula) is a plausible distractor because it also presents with nasal regurgitation; however, oronasal fistula is a distinct entity arising from cleft palate surgery or hard-palate defects (at the oro-nasal junction), not from post-extraction socket perforation. Option B (sinusitis without communication) may cause bad taste but does not explain the fluid regurgitation symptom. Options C and E lack any temporal or anatomical plausibility.
Reference: UK NHS OMFS Oro-Antral Communication Advice Leaflet and Tayside Oral Surgery Referral Guidance; Chekaraou SM, Benjelloun L, El Harti K. Management of oro-antral fistula: Two case reports and review. Ann Med Surg (Lond). 2021 Sep 4;69:102817. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8429925/