Infield masticatory muscle activity in subjects with pain-related temporomandibular disorders diagnoses.

OBJECTIVES: Pain-related temporomandibular disorders (TMDs) are the most prevalent conditions among TMDs. There is contrasting evidence available for association of pain-related TMD and masticatory muscle activity (MMA). The present investigation assesses the associations between MMA levels of masseter and temporalis muscles during awake and sleep among pain-related TMD diagnostic groups. SETTING AND SAMPLE POPULATION: The department of Oral Diagnostic Sciences, University at Buffalo. Twenty females and six males participated in this study. MATERIAL AND METHODS: Using the diagnostic criteria for temporomandibular disorders (DC-TMDs), participants were diagnostically categorized. Subjects used a custom monitoring system, which recorded infield muscle activities. A factorial model tested for association between independent variable (muscle, time period, MMA level, and diagnostic group) effects and the logarithm of MMA. Greenhouse-Geisser test was used to determine any statistically significant associations (p≤0.003). RESULTS: No statistically significant association was found between four-way, three-way, and two-way analyses. However, among the main effects, range of magnitudes was the only variable to be statistically significant. Although the data suggest a trend of increased masseter MMA in the pain-related TMD diagnoses group both during awake and sleep time periods, such observation is not maintained for the temporalis muscle. In addition, temporalis MMA was found to be higher in the pain-related TMD diagnoses group only at extreme activity levels (<25 and ≥80% ranges). CONCLUSION: This data support the association between masticatory muscle hyperactivity and painful TMD conditions.

Association between waking-state oral parafunctional behaviours and bio-psychosocial characteristics.

The term 'oral parafunctional behaviours' encompasses behaviours that are different from those required for, or associated with, physiological functional needs such as mastication, communication, swallowing or breathing. Previous reports have associated waking-state oral parafunctional behaviours with biopsychosocial characteristics such as female gender, presence of psychological symptoms, intensity of pain and pain-related temporomandibular disorders (TMD) diagnosis. However, the findings have been inconsistent, possibly due to methodological limitations and differences. In the present investigation, we aim to determine whether any association is present between waking-state oral parafunctional behaviours and biopsychosocial characteristics. All participants were investigated using a set of standardised and validated self-reporting questionnaires and diagnostic criteria for temporomandibular disorders (DC/TMD) examination protocol for clinical characterisation. Univariate analysis found that self-reported waking-state oral parafunctional behaviours were statistically significantly associated with presence of anxiety, depression and physical symptoms, pain intensity and TMD diagnosis. However, forward model multiple linear regression analysis indicated that only self-reported presence of physical and depression symptoms could explain statistically significant portions of the variance in self-reported waking-state oral parafunctional behaviours.