Lateral pterygoid muscle and its relationship to the meniscus of the temporomandibular joint.

OBJECTIVE: The theory of internal derangement of the temporomandibular joint involves the anterior displacement of the meniscus, which is thought to be the result of hyperactivity of the lateral pterygoid muscle. There is, however, a great deal of confusion with respect to the attachment of this muscle to the meniscus. This anatomic study reexamines the meniscal attachment of the lateral pterygoid muscle, in particular, the upper head of this muscle. STUDY
DESIGN: The anatomic relationship between the lateral pterygoid muscle and the meniscus was examined in the postmortem specimens of 25 males and 15 females between the ages of 7 to 85 years.
RESULTS: In 65% of specimens, the upper head of the lateral pterygoid muscle was attached to the medial aspect of the capsule, meniscus, and to the pterygoid fovea of the condyle. In 27.5% of specimens, the upper head was attached solely to the condyle; in the remaining 7.5% of cases, there were other types of attachments of the lateral pterygoid muscle to the meniscus.
CONCLUSION: This study confirms that the lateral pterygoid muscle has a variable attachment to the meniscus. The role of this muscle in the displacement of the meniscus is still unknown and further research into temporomandibular disorders should involve the investigation of other structures in the craniomandibular complex.