Oral Surgery · single question
In which direction is the condylar head MOST likely displaced in a subcondylar fracture?
Show answer and explanation
Correct answer: A. Anterior and medial
In a subcondylar fracture, the fractured condylar fragment is displaced ANTERIORLY and MEDIALLY due to the pull of the lateral pterygoid muscle, which inserts on the condylar neck and pterygoid fovea. The lateral pterygoid protrudes the condyle anteriorly and pulls it medially. This is why subcondylar fractures often cause contralateral open bite and deviation of the mandible toward the fractured side.
- A. CORRECT. The lateral pterygoid muscle pulls the fractured condyle anteriorly and medially — the classic displacement direction in subcondylar fractures.
- B. Incorrect. Posterior-lateral displacement would require a different force vector — the lateral pterygoid does not pull posteriorly.
- C. Incorrect. Lateral-only displacement does not account for the anterior vector of the lateral pterygoid.
- D. Incorrect. Posterior displacement would require a posteriorly directed force — not the case with lateral pterygoid muscle action.