Oral and Maxillofacial Surgery
What this domain tests
This domain tests surgical judgment: preoperative assessment, local anesthesia, odontogenic infection, trauma, third molar surgery, hemorrhage, and complication management. The exam favors safe sequencing and recognition of emergencies.
Core rules and concepts
- Preoperative assessment covers airway, medical history, bleeding risk, anticoagulants, bisphosphonate exposure, allergies, and informed consent.
- Odontogenic infection spreads along fascial planes. Ludwig angina is bilateral submandibular and sublingual involvement with floor-of-mouth elevation and airway risk. Secure the airway first, give intravenous antibiotics, and drain surgically.
- Mandibular fracture signs include malocclusion, step deformity, mobility, and inferior alveolar nerve paresthesia. Le Fort I, II, and III fractures involve progressively higher maxillary levels.
- Local anesthetic maximum doses must be calculated by weight and concentration. Lidocaine is commonly cited as 4.4 mg/kg without epinephrine and 7 mg/kg with epinephrine; always confirm the formulary and patient factors.
- Nerve injury after third molar surgery requires documentation and review. Most injuries are neuropraxic; persistent severe deficits may need specialist assessment.
- Hemorrhage management includes pressure, local hemostatic agents, tranexamic acid, and reversal of anticoagulation when appropriate.
Worked example
A patient has bilateral submandibular swelling, trismus, dysphagia, and an elevated floor of the mouth. The reasoning is Ludwig angina with impending airway compromise. The correct sequence is airway assessment and control, intravenous antibiotics, and urgent surgical drainage; do not wait for imaging if the airway is threatened. Antibiotics alone are insufficient because pus and tissue tension must be decompressed.
Traps that cost marks
Treating a spreading odontogenic infection with oral antibiotics alone is unsafe. Do not ignore trismus, dysphagia, or voice change. Do not misdiagnose a condylar fracture as a simple sprain when there is malocclusion. Also avoid extracting a tooth in acute infection before drainage when the airway is at risk.