Ultrasonographic Evaluation of Masseter Muscle in Temporomandibular Joint Dysfunction: Preliminary Study

Objective: The objective of this study was to evaluate the relationship between temporomandibular disorders (TMD) and masseter muscle thickness in a Turkish population, utilizing ultrasonographic measurements in relation to gender and parafunctional habits.Methods: A total of 68 masseter muscle ultrasonound images were analyzed from 34 individuals (17 males and 17 females) aged between 20 and 30 years. Masseter muscle thickness measurements were obtained at rest, during contraction, and at maximum mouth opening. The data were evaluated according to gender, the presence of parafunctional habits, chewing side preference, and TMD diagnosis. Statistical analysis was performed to determine significant associations between these variables. Independent samples t-test, paired t-test and Fisher’s exact test were used for statistical comparisons, with significance set at p < .05.Results: TMD were present in 50% of the study population. Masticatory muscles pain (MFP) was reported in 38.2% of the cases. Chewing preference was bilateral in 67.6%, right-sided in 23.5%, and left-sided in 8.8% of participants. Independent samples t-test, paired t-test and Fisher’s exact test were used for statistical comparisons, with significance set at p < .05.There was no statistically significant difference in muscle thickness measurements between the dominant and non-dominant sides in individuals with unilateral chewing habits (p >.05). TMD was observed in 69.2% of individuals with MFP, compared to 38.1% of those without MFP. A statistically significant association was found between masseter asymmetry and unilateral chewing (p