sphenomandibular

The sphenomandibular ligament is a fibrous band that functions as an accessory ligament of the temporomandibular joint (TMJ). It originates from the spine of the sphenoid bone and inserts on the lingula of the mandible near the mandibular foramen, running downward and forward along the medial aspect of the mandible. The ligament is relatively slender and lies within the pterygomandibular region as part of the TMJ’s soft tissue structures.

Function and movement: The sphenomandibular ligament helps limit excessive depression and protrusion of the mandible. It is usually slack during normal jaw movement and becomes taut with wide opening or forward movement of the jaw, contributing to passive stabilization rather than active movement.

Clinical significance: In dentistry and maxillofacial anatomy, the ligament serves as an important surface landmark for procedures such as inferior alveolar nerve blocks and related injections. Radiographic imaging can visualize the ligament, and rare cases of calcification or thickening may be seen, which can be associated with TMJ-related symptoms in some individuals.

Anatomical relations: The ligament lies medial to the ramus of the mandible and is in proximity to the inferior alveolar neurovascular bundle as it travels toward the lingula near the mandibular foramen. It is one of the three principal ligaments associated with the TMJ, alongside the stylomandibular and temporomandibular ligaments.