Post-Extraction Deep Space Infection — ORE Part 1 MCQ

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ModerateOral SurgeryPost-Extraction Deep Space InfectionORE Part 1

A patient presents with a unilateral sore throat and difficulty swallowing 3 days after surgical removal of a lower third molar. They have trismus (18 mm mouth opening) and a temperature of 38.7°C. What is the most likely complication?

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Correct answer: A — Pterygomandibular or parapharyngeal space infection spreading from the extraction site

Explanation lettering: D = shown as B · B = shown as C · E = shown as D · C = shown as E

The clinical triad of fever (38.7°C), restricted mouth opening (trismus at 18 mm), and pharyngeal symptoms (sore throat, dysphagia) appearing 3 days after lower third molar extraction is pathognomonic for deep space neck infection, most commonly involving the pterygomandibular or parapharyngeal space. Odontogenic infections are now the leading cause of deep neck space infections. The anatomical proximity of the mandibular third molar to these fascial planes, combined with the temporal course and constellation of signs, makes this the only defensible answer. Option B is incorrect because fever and significant trismus are not normal post-operative findings. Option C is implausible because the timing and focal nature point to an extraction-related source, not coincidental tonsillitis. Options D and E lack clinical support. Urgent referral for imaging (contrast-enhanced CT), blood cultures, broad-spectrum antibiotics, and possible surgical drainage is required.

Reference: Role of early extraction of odontogenic focus in deep neck infections. Retrospective study, 68 patients, 2022. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9805327/ Combined with Deep neck infection after third molar extraction: A case report. 2017. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5666216/