Page 13 - Demo

General introduction and overview111General introductionThe temporomandibular joint (TMJ) plays a role in many functions such as mastication, swallowing, talking, facial expressions, breathing, airway support and even maintaining the correct pressure of the middle ear. The joint can perform both translative and rotational movements and subjected to more cyclic loading and unloading than any other joint in the body. As a result, temporomandibular disorders (TMDs) are far from rare.(1) A 2008 study by the National Health Interview Survey concluded that up to 5% of all Americans deal with TMD-related pain(2), and a study conducted by Janal et al.(3) reported that up to 10% of all female patients examined had a TMD. Despite this high prevalence, in most cases conservative therapy such as physiotherapy and pharmacotherapy will suffice as treatment. Yet in about 5 to 10%, symptoms persist, demanding a more invasive approach.(4,5) which can range from a simple arthrocentesis to ultimately total joint replacement surgery. (1,6) TMJ anatomyTo better understand the function of the temporomandibular joint, as well as the total joint replacement (TJR) (procedure), a comprehensive knowledge of this diarthrosis’ anatomy is needed. The TMJ is comprised of the head of the mandibular condyle and the temporal glenoid fossa. The condyle is an ovoid process at the superior part of the mandibular ramus. It has a convex form and is wider in the mediolateral sense (15-20 mm) than in the anteroposterior direction (8-10 mm), with the medial side of the condyle being directed more posteriorly compared to the lateral side. The articular surface of the condyle is located on the anterosuperior part of the condyle.(7)Anteriorly of the tympanic plate, the articular temporal component can be found and shows several landmarks. Most anteriorly, the articular eminence and tubercle are located. The eminence has a strong incline, which becomes nearly horizontal towards the glenoid fossa, forming the preglenoid plane. The centrally located glenoid fossa is widest in the mediolateral direction, as the condyle is seated in this fossa. Posteriorly, Nikolas de Meurechy NW.indd 11 05-06-2024 10:14