Temporomandibular Joint Injection

Indications and Clinical Considerations

Injection of the temporomandibular joint is indicated as an important component in the management of temporomandibular joint dysfunction, in the palliation of pain secondary to internal derangement of the joint, and in the treatment of pain secondary to arthritis of the joint. Temporomandibular joint dysfunction (also known as myofascial pain dysfunction of the muscles of mastication ) is characterized by pain in the joint itself that radiates into the mandible, ear, neck, and tonsillar pillars. Headache often accompanies the pain of temporomandibular joint dysfunction and is clinically indistinguishable from tension-type headache. Stress is often the precipitating or exacerbating factor in the development of temporomandibular joint dysfunction. Dental malocclusion may also play a role in the evolution of temporomandibular joint dysfunction. Internal derangement and arthritis of the temporomandibular joint may manifest as clicking or grating when the joint is opened and closed and may be easily heard on auscultation of the opening and closing joint ( Figs. 1.1 and 1.2 ). Other causes of temporomandibular joint pain are listed in Box 1.1 .

Plain radiographs and computed tomography may help identify arthritic changes, with magnetic resonance imaging and ultrasound imaging also being useful in identifying articular disk abnormalities and other abnormalities of the temporomandibular joint ( Figs. 1.3, 1.4, and 1.5 ). If the condition is not promptly treated, the patient may experience increasing pain in the these areas, plus limitation of jaw movement and opening. Recently, the injection of autologous blood and platelet-rich plasma into the temporomandibular joint has gained popularity in the treatment of recurrent temporomandibular joint hypermobility dislocation ( Fig. 1.6 ). This technique is also useful in the injection of other substances into the temporomandibular joint, such as hyaluronic acid derivatives and tenoxicam.

Clinically Relevant Anatomy

The temporomandibular joint is a true joint divided into an upper and a lower synovial cavity by a fibrous articular disk. In health, the disk and muscles allow the joint, muscles, and articular disk to move in concert ( Fig. 1.7 ). The internal derangement of this disk may result in pain and temporomandibular joint dysfunction, but extracapsular causes of temporomandibular joint pain are much more common. The joint space between the mandibular condyle and the glenoid fossa of the zygoma may be injected with small amounts of local anesthetic and corticosteroid. The temporomandibular joint is innervated by branches of the mandibular nerve. The muscles involved in temporomandibular joint dysfunction often include the temporalis, masseter, and external and internal pterygoid, and may include the trapezius and sternocleidomastoid. Trigger points may be identified when these muscles are palpated.