Temporomandibular joint arthritis: possible etiologic factors and arthritis classification.

Aim The aim of this paper was to classify the signs of the various types of arthritis that are related to the TMJ according to the etiologic factors. TMJ Arthritis classification is presented according to the levels of inflammation, in order to summarize current knowledge about the inflammatory theory, with emphasis on recent research on pathophysiology and radiographic differential diagnosis of TMJ arthritis types: Osteoarthritis (low- inflammatory arthritic condition), results from increased pressure on a particular joint or fragility of the cartilage matrix and represents a destructive process by which the bony articular surfaces of the condyle and fossa become altered.  Osteoarthrosis (non-inflammatory arthritic condition) is an adaptive stage, involving morphologic changes of the articular structures, not associated with significant alterations in the mechanical joint function. Altered articular surfaces of the TMJ may be considered as normal adaptive responses to increased loading, rather than pathological degenerative changes.  Polyarthritis or polyarticular arthritis (high–inflammatory arthritic conditions), present similar symptoms and clinical findings as osteoarthritis but have different causes. The classic type of high-inflammatory arthritis is rheumatoid arthritis. Conclusion The clinician must be aware of the various systemic conditions that may affect the TMJ and the stomatognathic system as a whole. In this way the proposed dental treatment plan can and should be adjusted to the needs of the patient taking under consideration the manifestations of the disease in the stomatognathic system.