History factors associated with symptoms of temporomandibular disorders.

Differences in prevalence of head or neck trauma, orthodontic treatment and molar oral surgery procedures reported by individuals were compared among patients with temporomandibular disorders (TMD) and with two comparison groups (a sample of asymptomatic individuals, and a sample with mild or early signs). Association to specific TMD symptoms was tested amongst the comparison groups. Trauma was the most significant factor characterizing TMD patients. History of trauma was also more common among those otherwise normal but symptomatic individuals in the non-patient comparison group. Specific TMD symptoms were significantly associated with history of trauma in the comparison group. Significantly more women TMD patients had a history of orthodontic and molar oral surgery treatment than the asymptomatic comparison group. History of orthodontics was also associated with the symptomatic sample of the comparison group in women, but it was not significantly related to any specific TMD symptoms. Symptomatic members of the comparison group could not be differentiated based upon history of molar oral surgery. Certain risk factors may have been delineated, but causal relationship of treatment requires study of co-existing and predisposing behavioural and structural factors.