3D Anatomy of Human Otomandibular Soft Tissues and its Significance for the Origin of the Temporomandibular Joint Articular Disc

Abstract

Understanding the ligamentous and muscular connections between the temporomandibular joint (TMJ) and middle ear ossicles is important for health sciences and ENT training and diagnosing comorbidity between TMD and otological pain, as well as exploring the developmental and evolutionary origins of the modern mammalian jaw joint and ear. Although we know the anterior mallear ligament (AML) is the vestige of the embryonic Meckel's cartilage, the developmental and evolutionary origins of the discomallear ligament (DML) are not well understood and may shed light on the origins of the TMJ disc itself. Like other authors, we hypothesize that the DML may be a vestige of the lateral pterygoideus muscles' primitive attachment to the articular bone, or malleus. To better appreciate the 3D anatomy of the connection between the human TMJ and middle ear, we built a 3D model of the jaw joint, ossicles, disc, ligaments and other important features of the region. We used diffusible iodine‐contrast enhanced CT scanning (diceCT) to visualize the anatomy of the temporal region of human cadaveric material. Iodine offers contrast to soft tissues using microtomography enabling anatomical detail in high‐resolution detail. We identified connections between the DML and the TMJ disc that complement previous investigations showing this approach offers promise for exploring the otomandibular ligaments of other species. We will expand our study to include additional human individuals, non‐human primates and mammals to better understand the muscular connections between the jaws and middle ear, and the origin of the TMJ articular disc. These data also provide unique visualizations of complicated, small, but important regions of the body useful for education and training.Support or Funding InformationNSF IOS 1457319, NSF EAR 1631684, Missouri Research Council, University of Missouri Department of Pathology and Anatomical SciencesThis abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.