Oral and Maxillofacial Surgery
What this domain tests
The exam checks surgical decision-making: when to extract, how to plan an impacted third molar, how to recognise and manage complications, and how to handle odontogenic infection and trauma.
Core rules
- Pre-extraction assessment: medical history and anticoagulant status, radiographic relationship to the inferior alveolar canal and maxillary sinus, root morphology, bone density and access.
- Third molar assessment uses Pell and Gregory (depth relative to the occlusal plane and ramus) and Winter's classification (mesioangular, distoangular, horizontal, vertical, buccal/lingual).
- Oroantral communication is confirmed by a nose-blowing test; manage with a buccal advancement flap or palatal rotation flap, sinus precautions and review. A communication larger than about 5 mm or with established sinusitis may need referral.
- Dry socket (localised alveolar osteitis) presents 2–4 days post-extraction with severe pain, empty socket and no pus: irrigate, place a medicated dressing, give analgesia, review.
- Odontogenic infection: incision and drainage plus removal of the cause. Ludwig's angina is a bilateral submandibular, sublingual and submental cellulitis with airway threat - secure the airway first, then drainage and intravenous antibiotics.
- Mandibular fractures: Champy's line describes the ideal line of osteosynthesis, running along the external oblique ridge for angle fractures, avoiding the inferior alveolar nerve.
Worked example
Three days after a lower third molar extraction, a patient has severe throbbing pain, an empty socket with exposed bone and no swelling. Reasoning: the timing, pain severity and absence of pus fit alveolar osteitis, not infection. Treat by irrigating the socket, placing a medicated dressing and prescribing analgesia; antibiotics are not indicated unless there is spreading infection.
Traps
Prescribing antibiotics for every extraction; missing an oroantral communication because the nose-blowing test was not done; draining an infection without removing the causative tooth; forgetting anticoagulant and bisphosphonate history.