The systemic pathophysiologic conditions that have potential to affect temporomandibular disorders are extensive and may include degenerative, endocrine, infectious, metabolic, neoplastic, neurologic, rheumatologic and vascular disorders. Conditions involving altered collagen metabolism can also be involved. Their effects can be seen both centrally and locally. When these are present and are recognized as having the potential to affect a TMD, coordination of care with the patient’s primary care physician is recommended.

One of the more commonly occurring systemic conditions that can clearly affect both the causation and the treatment of a TMD is a condition referred to as Systemic Ligamentous Laxity (or Hypermobility Syndrome). Its effect is seen most commonly in patients who demonstrate an internal derangement of the temporomandibular joint. A question that should be asked of all TMD patients is whether they have more joint laxity than other people, or are they “double jointed”. But not infrequently, a patient will deny these descriptive terms and yet demonstrate the condition when tested. The most simple test for determining such laxity is whether they can bend their thumb down to touch their wrist. A positive finding confirms this diagnosis. Their ability to move joints more freely than others will often be seen in their opening range of motion and with lateral jaw movements. This laxity appears to be contributory to the development of an internal derangement, although the research is not firm on this question. This level of laxity occurs more commonly in women than in men, and is more likely to be seen in younger individuals.