|
Temporomandibular joint syndrome is characterized by pain and tenderness in the jaw muscles, sound and/or pain over the temporomandibular joint (TMJ), with limitation of mandibular movement.(1) The disorder has received much attention in the lay press in recent years as a cause of chronic headache and facial pain. Although severe cases may require dental or oral surgical intervention, most TMJ dysfunction is psychophysiologic in origin, the consequence of chronic bruxism (nocturnal jaw clenching and teeth grinding). This tension-relieving oral habit develops in response to situational and intrapsychic stresses and can lead to masticatory muscle fatigue and spasm.(2)
In its 1996 consensus statement, the National Institutes of Health Consensus Development conference defined temporomandibular disorders as follows: "Temporomandibular disorders (TMD) refer to a collection of medical and dental conditions affecting the temporomandibular joint (TMJ) and/or the muscles of mastication, as well as contiguous tissue components. Although specific etiologies such as degenerative arthritis and trauma underlie some TMD, as a group these conditions have no common etiology or biological explanation and comprise a heterogeneous group of health problems whose signs and symptoms are overlapping, but not necessarily identical."(3) In clinical practice the term TMD has been assigned to a very wide range of symptoms, varying from noticeable but clinically insignificant signs to seriously debilitating pain or dysfunction. For this reason, the term TMD is not universally endorsed, and generally accepted, scientifically based guidelines for diagnosis and management are still unavailable.
In most instances, the problem remains extracapsular, with no actual derangement of the temporomandibular joint. However, if there has been severe and prolonged bruxism, there may be intracapsular joint derangement. This may lead to degenerative disease of the joint. Intracapsular TMJ disease may be differentiated from extracapsular by the presence of markedly limited jaw movement, jaw deviation when opening the mouth, and presence of crepitus and clicking on jaw movement. There is, however, significant overlap of symptoms, and jaw clicking may even be noted in normal patients. Confirmation of internal joint derangement requires a MRI of the temporomandibular joint. This method provides the best visualization of the soft tissues and bony structures, but should be reserved for patients in whom conservative measures have failed and internal derangement is suspected.
Other etiologies include degenerative arthritis and trauma, ankylosis, growth disorders, recurrent dislocation, neoplasia, condyle fracture, and systemic illness.
|
