Assessment of mandibular kinematics values and its relevance for the diagnosis of temporomandibular joint disorders.

BACKGROUND/PURPOSE: Temporomandibular disorders (TMD) are common conditions that involve the temporomandibular joints (TMJs), jaw muscles, or both, and can cause alteration in the mandibular kinematics. The aim of this study was to assess the relationship between mandibular kinematics and temporomandibular joint disorders (TMJD) as a clinical tool for evaluation and diagnosis of these patients. MATERIALS AND METHODS: A retrospective study based on the analysis of the clinical findings from patients' charts was carried out, with a sample size of 476 patients. Statistical analysis was made with chi-square test for qualitative variables and student t-test for quantitative variables. Then, odds ratio with its confidence interval were calculated. A p value < 0.05 was considered statistically significant. RESULTS: Most patients were female (80.7%) and between 16 and 25 years old. Disc displacement with reduction (DDwR) and subluxation were associated with increased kinematic parameters, while disc displacement without reduction (DDwoR) and retrodiscitis were associated with decreased kinematic values. A soft end feel was related to osteoarthritis (OA). Structural incompatibility was most prevalent in older patients. CONCLUSION: Mandibular kinematic values are associated with specific temporomandibular joint disorders and could be considered as a useful clinical tool to perform the right diagnosis of TMJD.

Assessment of association between muscular diagnosis in temporomandibular disorders with mandibular kinematics.

Objective: To study the association between mandibular kinematics and muscular diagnoses in temporomandibular disorders (TMD). Method: Retrospective, descriptive clinical study based on an analysis of 370 clinical records of muscle diagnoses in TMD. Statistical analysis was performed with the SPSS program. Results: Five different muscle diagnoses were considered. Myospasm and centrally mediated myalgia were discarded from the statistical analysis because of their low incidences. The diagnoses included in the analysis were protective co-contraction, myofascial pain, and myalgia. Decreased mandibular kinematics in the frontal and horizontal planes were related to myofascial pain. Mandibular kinematics with deflection in opening values decreased in the frontal plane, but intermediate or increased values in the horizontal plane were related to the protective co-contraction. Muscle pain with normal or increased mandibular kinematics was associated with a diagnosis of myalgia. Conclusion: Values of mandibular kinematics are correlated with the muscular diagnoses in TMD and are useful for diagnosis.