Anatomy & Histology · single question
When the articular disc of the TMJ is anteriorly displaced, which muscle is primarily involved?
Show answer and explanation
Correct answer: B. Superior head of the lateral pterygoid
The superior head of the lateral pterygoid attaches directly to the articular disc (and condylar neck). During jaw opening, the inferior head contracts; the superior head controls and stabilizes the disc. In disc displacement, the superior head of the lateral pterygoid is dysfunctional/hyperactive, pulling the disc anteriorly.
- A. ❌ Medial pterygoid elevates the mandible — it does NOT attach to or control the articular disc.
- B. ✅ Superior head of the lateral pterygoid attaches to the articular disc — its dysfunction is the primary muscle involvement in disc displacement.
- C. ❌ Masseter elevates the mandible — does not attach to the articular disc.
- D. ❌ Temporalis elevates and retrudes the mandible — does not attach to the articular disc.
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