Association between generalized joint hypermobility and signs and diagnoses of temporomandibular disorders

The aim of this study was to analyze whether generalized joint hypermobility (GJH) is a risk factor for temporomandibular disorders (TMD). We examined 895 subjects (20-60 yr of age) in a population-based cross-sectional sample in Germany for GJH according to the Beighton classification and for TMD according to the Research Diagnostic Criteria for TMD (RDC/TMD). After controlling for the effects of age, gender, and general joint diseases using multiple logistic regression analyses, hypermobile subjects (with four or more hypermobile joints on the 0-9 scale) had a higher risk for reproducible reciprocal clicking as an indicator for disk displacement with reduction (Odds Ratio (OR) = 1.68) compared with those subjects without hypermobile joints. Concurrently, subjects with four or more hypermobile joints had a lower risk for limited mouth opening (< 35 mm; OR = 0.26). The associations between GJH and reproducible reciprocal clicking or limited mouth opening were statistically significant in a trend test. No association was observed between hypermobility and myalgia/arthralgia (RDC/TMD Group I/IIIa). In conclusion, GJH was found to be associated with non-painful subtypes of TMD.