Magnetic resonance imaging evaluation of discal attachment of superior head of lateral pterygoid muscle in individuals with symptomatic temporomandibular joint

ObjectiveThere has been much speculation on the role of the lateral pterygoid muscle (LPM) in temporomandibular joint (TMJ) internal derangement. As a result, this muscle has been the focus of many reports attempting to understand its possible role in TMJ internal derangement.Study DesignMagnetic resonance (MR) imaging exams of 108 TMJ disorder patients were assessed for types of morphologic insertion of the superior head of LPM to the condyle-disc complex and possible correlation with disc position. The investigation was made on the sagittal T1-weighted MR images in closed- and open-mouth positions.ResultsThere was a lack of correlation between attachment pattern of the superior head of LPM and presence or absence of anterior disc displacement.ConclusionsThe explanation of anterior disc displacement based on the attachment type of the superior head of LPM is unlikely; the type of muscular insertion does not appear to have a predictive or prognostic value for TMJ internal derangement.