Joint Sounds Analysis and its Relationship with the Temporomandibular Disorders Severity

Objectives: Analyze parameters which enable the evaluation of the severity of joint sounds during Electrovibratography (EVG): Amplitude Peak (AP) and Frequency Peak (FP); analyze the correlation between the data of EVG with Temporomandibular Disorder (TMD) severity given by Craniomandibular Index (CMI). Methods: 79 subjects with TMD were submitted to clinical examinations of the Research Diagnostic Criteria (RDC/TDM axis I) for diagnosis of TMD, CMI to investigate the severity of the dysfunction. 18 patients were part of the control group and all patients underwent electrovibratography. Results: The AP was greater in left Temporomandibular Joint (TMJ) (3.71 ± 7.73 opening and 2.71 ± 3.49 closing) as well as the opening movement (3.71 ± 7.73 left TMJ and 2:42 ± 5.19 right TMJ). From the FP, higher values were also found in the left joint (71.31 ± 70.41 opening and 47.99 ± 52.46 closing) and during the opening movement (71.31 ± 70.41 left TMJ and 52.09 ± 45.35 right TMJ). For the control group there were no significant differences. Furthermore correlation between the CMI and the FP in the left TMJ during opening was found (p = 0.02). Conclusion: Joints of subjects with TMD had a higher AP and FP as compared to a control group and the left TMJ showed higher values. The frequency peak may be related to the severity of the disorder, and the EVG assists in the formulation of diagnosis and assessment of severity of articular TMD.