Assessment of the newly developed mandibular movement analyzing device

Objectives: The objective of this study was to investigate the sensitivity of the newly developed mandibular movement analyzing device for premature contact, using 3-axis acceleration sensor. Methods: The subjects of this study consisted of volunteers, who had the personal normal occlusion; 1 females and 5 males; 26-34 years old. This project was approved by the Institutional Review Board for Human Subjects Protection at the Tokyo Medical & Dental University (H18-0226).We captured mandibular movement as the change of acceleration, fixing the 3-axis acceleration sensor (Matsushita AGS61231) on mentum. The X-axis of the sensor represents the side shift movement, and the Y and Z-axis represent the movement on sagittal plane. We measured the changes of acceleration during the tapping movement of normal occlusion, and of premature contact putting tinfoil on the mandibular first premolar of the habitual masticatory side. The mean of the max value for 10 strokes after the third stroke of tapping movement was calculated. The value of normal occlusion and premature contact was examined for a statistically significant difference by means of paired t-test at a level of 5% (SPSS 11.5J). Results: While in X-axis there was highly significant difference (p=0.02) between normal occlusion (0.386±0.168) and premature contact (0.718±0.255), in Y and Z-axis there were no significant differences. Conclusions: The results of this study suggested that we could detect the premature contact during tapping movement with the newly developed device using 3-axis acceleration sensor.