Temporomandibular Joint Imaging

Temporomandibular joint (TMJ) imaging involves the evaluation of intra-articular abnormalities, lockjaw, and soft tissue changes associated with inflammatory arthritides. The articular disc can be divided into three distinct regions: a thickened anterior and posterior band, and a central intermediate zone. The three distinct regions of the disc contribute to the bowtie morphology as seen in sagittal T1-weighted closed-mouth magnetic resonance imaging (MRI) images. Posteriorly the disc blends with the bilaminar zone, which is composed of the superior and inferior retrodiscal lamina. For patients with limited opening due to discomfort, it is important to obtain a vertical opening of at least 20-25 mm in order to ensure adequate translation of the discs for open view evaluation. Although anterior displacement of the disc is the most common type of displacement, the disc may also be displaced posteriorly, laterally, and/or medially in relation to the condyle.