Anterior disc position has been highly correlated with temporomandibular disorders (TMD). It was hypothesized that internal derangement of the temporomandibular joint may be a part of a joint phenotype that imparts an increased risk for joint disorders. If this hypothesis is true, an increased prevalence of joint disorders in indibiduals diagnosed with displaced discs should be expected. A total of 263 symptomatic TMD patients and 82 asymptomatic volunteers was examined. Asymptomatic volunteers with anteriorly displaced discs were twice as likely as asymptomatic volunteers without disc displacements to report pain/dysfunction in other joints. Symptomatic patients with and without displaced discs reported an increase in other joint problems three or four times greater than in asymptomatic subjects. Compared to symptomatic TMD patients without disc displacement, symptomatic TMD patients with anteriorly displaced discs were also twice as likely to report other family members as being affected by TMD. Familial aggregation of TMD and an increased prevalence of other joint problems in these individuals may represent more than a serendipitous occurrence.