The sphenomandibular ligament (internal lateral ligament) is a flat, thin band which is attached superiorly to the spina angularis (spine) of the sphenoid bone, and, becoming broader as it descends, is fixed to the lingula of the mandibular foramen. The function of the sphenomandibular ligament is to limit distension of the mandible in an inferior direction. It is slack when the temporomandibular joint (TMJ) is in closed position.