Oral Behaviors and Parafunctions: Comparison of Temporomandibular Dysfunction Patients and Controls.

The aim of this study is to evaluate the frequency of oral behaviors in patients with temporomandibular disorders (TMD) and a control group without TMD.In this baseline case-control study, 260 controls and 260 subjects with TMD completed the oral behaviors checklist defined as a "self-report scale for identifying and quantifying the frequency of jaw overuse behavior" and underwent clinical examinations using the DC/TMJ international examination form (version May 12, 2013). Relationships of oral parafunctions' frequencies between groups were examined. The statistical analysis was performed with IBM SPSS Statistics 23 software.Age and gender distribution in the study groups did not reveal statistical differences (P > 0.05). Multivariate logistic regression analysis was conducted to establish system of independent oral behaviors for prognosis TMD. The stepwise regression analysis demonstrated that very frequent expression of holding, tightening, or tense muscles is associated with 10.83 times (P < 0.05) higher risk of TMD, grinding teeth together during waking hours with 4.94 times (P < 0.05) higher risk, and sustained talking with 2.64 times (P < 0.05) higher risk of TMD. By contrast, it was determined that 3 oral behaviors were less common in the TMD patients compared with the control group: clenching teeth together during waking hours, facing grimaces, and yawning (P < 0.05). The individuals with TMD reported a significantly higher frequency of 10 behaviors (P < 0.05), 3 of which may be regarded as independent risk factors for TMD. In addition, 3 oral behaviors were more frequently observed in the healthy subjects than in the TMD patients.