Evaluation of vertical facial height reduction and severity of temporomandibular joint disorders using Shimbashi number and cephalometric analysis.

Objective: This study was designed to evaluate the correlation between vertical dimension at occlusion (VDO) and various grades of temporomandibular disorders (TMDs) versus controls.Methods: Clinically measured Shimbashi number and radiographic cemento-enamel junction (CEJ-CEJ) measurements on 120 TMD patients and 40 controls were evaluated. Radiographic lateral cephalometric skull images of the patients were subjected to cephalometric analysis. The relationship between Shimbashi number, the cephalometric values, and its correlation with the degree of TMD were evaluated and statistically analyzed.Results: Shimbashi number and radiographic CEJ-CEJ values in the TMD patients were significantly lower than those in the controls. TMD severity appeared to increase with the increase in interincisal angle and the decrease in both Shimbashi number and radiographic CEJ-CEJ value.Conclusion: These findings indicate that radiographic evaluation of cephalograms is a reliable indicator of presence and degree of TMD, and the severity of TMD increases with the degree of reduction in VDO.

Assessment of craniocervical posture in TMJ disorders using lateral radiographic view: A cross-sectional study.

Objective: To determine the craniocervical posture in 120 subjects, 90 patients with temporo- mandibular joint disorders (TMD) of varying degrees were selected and compared with those of 30 healthy individuals.Methods: True lateral radiographs in the natural head position were obtained from TMD patients and healthy individuals. Linear measurements from the opisthion to the intersecting point of the craniovertebral angle, the opisthion to the tip of the spinous process of the seventh cervical vertebrae, and the body of Atlas to the lower border of the seventh cervical vertebrae were obtained. Data were analyzed by one way ANOVA followed by Scheffe's post hoc test.Results: Significant increases in craniovertebral, odontoid plane, and individual vertebral angles were noted in the TMD patients when compared with the healthy individuals.Conclusion: Significant postural changes in the skull in relation to the cervical vertebrae with dorsiflexion as a compensatory strategy were observed in this study.