The identification of temporomandibular joint disease through the masticatory cycle

The purpose of this study was to determine, by analyzing the masticatory cycle, the presence of TMJ disease prior to initiating any orthodontic treatment. Masticatory data from 80 pre-orthodontic patients were recorded in the frontal and sagittal planes and then analyzed and compared with the pre-established healthy masticatory data of Maruyama et al. 40% of the sample group presented with signs and/or symptoms of masticatory dysfunction and/or temporomandibular joint abnormalities (TMJA). Using Student's t test we found significant differences in the means for all seven parameters measured. Patients with TMJA exhibited significantly slower closing, occlusal and total cycle times, but faster opening. It was usually possible to determine which joint was compromised by the disease from the data.