What is the principal function of the temporomandibular (lateral) ligament?

Correct answer: D. To limit posterior and inferior displacement of the condyle, protecting the retrodiscal tissues

• A. The lateral pterygoid's superior head does attach to the disc, but that is a muscle–disc attachment, not the function of the temporomandibular ligament.
• B. Protrusion is produced by MUSCLE — the lateral pterygoid, assisted by the medial pterygoid and superficial masseter. Ligaments are passive restraints; they do not generate movement.
• C. Taste is carried by the chorda tympani (CN VII) and glossopharyngeal nerve (CN IX) and has no relationship to this ligament.
• D. CORRECT. The TEMPOROMANDIBULAR (lateral) LIGAMENT is the principal functional ligament of the joint. Its two components restrain the condyle: the outer oblique portion limits excessive DROPPING (inferior displacement) of the condyle during opening, while the inner horizontal portion limits POSTERIOR displacement. This posterior restraint is critically protective — behind the condyle lies the RETRODISCAL TISSUE, which is highly vascular and richly innervated, and would be a source of severe pain if compressed.

Note: The three TMJ ligaments: TEMPOROMANDIBULAR (lateral) — the functional one, limiting posterior and inferior condylar displacement. SPHENOMANDIBULAR and STYLOMANDIBULAR — accessory ligaments that provide only minor passive restraint. Ligaments do not stretch actively; once elongated, they do not return to their original length.