Temporomandibular Joint (ODS Learning Outcomes)

Temporomandibular Joint (TMJ) Components

• Articular Capsule: Surrounds the joint, attaching to the articular eminence, articular disc, and mandibular condyle. It encloses the joint.
• Synovial Tissue: Lines the inner surface of the articular capsule and is a connective tissue. This tissue aids in joint lubrication, essential for smooth movement.
• Articular Disc: A biconcave fibrous structure positioned between the temporal bone and the mandible. It facilitates smooth articulation, evenly distributing the load and preventing direct bone-on-bone contact. The disc is made up of dense fibrous connective tissue.
• Ligaments: Providing passive support and stability to the TMJ. Includes the stylomandibular ligament, running from the styloid process to the mandibular angle. Also, the sphenomandibular ligament, extending from the sphenoid bone to the mandible’s lingula. These ligaments restrict excessive or abnormal movements of the mandible.
• Mandibular Glenoid Fossa: A depression in the temporal bone, accommodating the condyle of the mandible. Covered in smooth cartilage, facilitating jaw movement
• Articular Eminence: Located anterior to the fossa, a sloping bony eminence that receives the mandibular condyle during jaw opening. Covered in cartilage, permitting smooth movement.
• Mandibular Condyle: Part of the mandible that articulates with the TMJ, exhibiting dense cortical bone. Covered in dense connective tissue and cartilage enabling smooth and controlled movement within the joint.

TMJ Movements

• Depression and Elevation: Upward and downward movement of the mandible (e.g., opening and closing the mouth).
• Lateral Deviation: Side-to-side movement of the mandible (e.g., moving the jaw from side to side).
• Protrusion and Retrusion: Forward and backward movement of the mandible (e.g., jutting the jaw forward or bringing it back).

Common TMJ Problems

• Myofascial Pain: The most prevalent TMJ condition, discomfort or pain affecting muscles controlling jaw function.
• Internal Derangement: Includes dislocated jaw, displaced articular disc, or condyle injury. This impairs normal joint function and cause pain.
• Degenerative Joint Disease: Conditions like osteoarthritis or rheumatoid arthritis affecting the TMJ, leading to deterioration of the joint.

This quiz focuses on the essential components of the Temporomandibular Joint (TMJ), including the articular capsule, synovial tissue, articular disc, and supporting ligaments. Test your knowledge on how each component contributes to the function and stability of the TMJ.