Kjeveledd

Kjeveledd, or temporomandibular joint (TMJ), is the synovial joint that connects the mandible (lower jaw) to the temporal bone of the skull. Each side of the head contains a TMJ located just in front of the ear, and these joints enable the jaw’s complex movements essential for chewing, speaking, and facial expression.

Anatomically, each TMJ consists of a mandibular condyle that sits within the mandibular fossa of the temporal bone, separated by an articular disc. The disc divides the joint into superior and inferior compartments and reduces friction during movement. The joint is surrounded by a fibrous capsule reinforced by ligaments, notably the lateral temporomandibular ligament, with the stylomandibular and sphenomandibular ligaments providing additional support. The muscles of mastication, especially the lateral pterygoid, masseter, and temporalis, drive movement. Sensory innervation comes mainly from the mandibular branch (V3) of the trigeminal nerve, with the joint capsule supplied by the auriculotemporal and masseteric nerves.

Functionally, the TMJ allows both hinge-like rotation (opening and closing) and gliding (protrusion, retrusion, and lateral movement). In the superior compartment, translational motion occurs, while the inferior compartment permits rotation. The articular disc helps maintain smooth articulation through these motions.

Clinically, the TMJ is a common source of pain and dysfunction, a condition often termed temporomandibular disorders (TMD). Symptoms include jaw pain, restricted movement, and noises such as clicking or crepitus. Causes are multifactorial, including muscle tension, disc displacement, degenerative changes, trauma, and factors like malocclusion, bruxism, and stress.

Diagnosis combines clinical examination with imaging. MRI best visualizes disc position; CT assesses bone structures; panoramic radiography offers a broad dental view. Treatment is typically conservative: education, soft diet, NSAIDs, physical therapy, and occlusal splints, with invasive options (arthrocentesis, arthroscopy, discectomy, or joint replacement) reserved for persistent or severe cases.