Читать книгу Temporomandibular Disorders - Robin J. M. Gray - Страница 53

When considering the common disorders of the TMJ, myofascial pain, (facial arthromyalgia/pain dysfunction syndrome), internal derangements, osteoarthrosis, and the response to trauma, the tissue changes are primarily inflammatory except in osteoarthrosis.

Osteoarthrosis is a term that has developed to distinguish between an acute and a chronic condition. Osteoarthrosis describes a non‐inflammatory degenerative disease. In osteoarthrosis, the disorder appears to be primarily degenerative, starting with changes within the bone and progressing through the surface tissues of the joint to subsequent involve degeneration of the articulatory surface and formation of erosion and eburnation of the surface of, usually, the mandibular condyle. These changes can also be seen, however, in the articulatory fossa (glenoid fossa). The difference therefore between osteo‐‘arthritis’ and osteo‐‘arthrosis’ is that the former is first recognised in the fluid surrounding the joint which then permeates the hard structures, whereas the latter starts in the hard structures permeating through the surfaces of the joint. From a patient's point of view, the encouraging feature is that, as the germinative mesenchyme cell layer remains throughout life, this can respond, as a result of ‘irritation’, to produce new tissue. Therefore, it is not uncommon for a patient who presents with osteoarthrosis of the TMJ to enter a phase of acute symptoms followed by a plateau stage followed by improvement of symptoms as remodelling and resurfacing of the condyle progress.

The clinical symptoms of osteoarthrosis include pain localised to the joint and limited movement which is worse with function. The clinical joint sound is crepitation, which is a grating or crunching sound from the joint that indicates a loss of the smooth articular surfaces. Crepitation can emanate from the articulating surfaces or the disc.