Contribution of magnetic resonance imaging in the biomechanical interpretation of the temporomandibular joint. Clinical case report

X-rays and tomography, in their different modalities, are used as auxiliary diagnostic elements in temporomandibular joint (TMJ) dysfunction, both in static and dynamic situations; however, because they only allow the observation of bone structures, magnetic resonance imaging (MRI) is the ideal method to analyze, among other structures, the articular disc. Among the internal disorders of the TMJ are the abnormal postural relationships between the disc, mandibular head, fossa and articular tubercle, which can even lead to a musculoskeletal condition causing noise, pain and functional limitation. The clinical evaluation of temporomandibular dysfunctions is complex, especially in asymptomatic patients; the Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD), place these entities within the AXIS I protocol, considering that the image is not strictly necessary. However, analyzing the disc situation statically and dynamically, with its surroundings, allows considering the loads that generate dysfunction, leading to the correct diagnosis, and selection of the best treatment. A clinical case is presented, an asymptomatic patient, without functional limitation, who reported a history of occasional mouth opening locking upon awakening. MRI was indicated, finding an abnormal position of the disc, in a static and dynamic situation; finding anterior displacement of the disc in the right and left TMJ in closed mouth position, dynamically anterior displacement without recapture in the right TMJ and with recapture in the left TMJ; Treatment was performed with Jaw Functional Orthopedics (JFO), obtaining changes in the dynamic disc-mandibular head relationship, anterior displacement with recapture of the right TMJ and total recapture of the left TMJ.