Different association between specific manifestations of bruxism and temporomandibular disorder pain.

INTRODUCTION: A growing body of evidence suggests that bruxism exists in two separate manifestations. However, little is known about the association between specific manifestations of bruxism and temporomandibular disorder (TMD) pain.

AIM: The aim of our study was to analyze the association between TMD pain and specific diagnoses of bruxism (sleep, awake, and mixed diagnosis of sleep and awake bruxism).

MATERIAL AND METHODS: 508 adult patients (296 women and 212 men), aged between 18 and 64 years (mean age 34±12 years), attending to a clinic for general dental treatment. Patients were asked to fill an anonymous questionnaire, consisting of three questions, verifying the presence of TMD pain and two forms of bruxism. All questions were based on the Polish version of the Research Diagnostic Criteria for Temporomandibular Disorders patient history questionnaire. Cross tabulation was done, and χ2 was used as a test of significance to find the association between the variables.

RESULTS: Awake bruxism was associated with TMD pain only in men (χ2 =7.746, p<0.05) while mixed diagnosis of bruxism was associated with TMD pain in both women (χ2 =10.486, p<0.05) and men (χ2 =4.314, p<0.05). There was no statistically significant association between sleep bruxism and TMD pain. Gender-related differences in the presence of all bruxism diagnoses were also statistically insignificant.

CONCLUSIONS: Interaction between sleep and awake bruxism may increase the risk for TMD pain. We suggest considering concomitance as a confounder, when studying sleep or awake bruxism.