🦷 TMJ (Temporomandibular Joint) – Quick High-Yield Notes

📍 What is TMJ?
A hinge + gliding type synovial joint between mandibular condyle and temporal bone.


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📌 Important Points (Exam + Clinical)

✅ Type of joint: Synovial, bicondylar, modified hinge
✅ Articular surfaces: Mandibular condyle + Mandibular fossa of temporal bone
✅ Articular disc: Fibrocartilage disc dividing joint into upper (gliding) & lower (hinge) compartments
✅ Movements:
• Opening & closing of mouth
• Protrusion & retraction
• Side-to-side grinding


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🧠 Muscles Involved

• Opening: Lateral pterygoid
• Closing: Masseter, Temporalis, Medial pterygoid
• Protrusion: Lateral + Medial pterygoid
• Retraction: Posterior fibers of temporalis


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🔌 Nerve Supply

Auriculotemporal nerve

Masseteric nerve (branch of V3)



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🩸 Blood Supply

Maxillary artery

Superficial temporal artery



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⚠️ Clinical Points

• Clicking sound = Disc displacement
• Pain near ear = TMJ dysfunction
• Trismus = Spasm of muscles of mastication