This study was performed to investigate the relationship between reproducibility of mandibular lateral movement and chewing movement in subjects with preferred chewing side. 44 dental students without any signs and symptoms of temporomandibular disorders participated in this study. BioEGN of the Biopak^® (BioResearch Inc. USA) was used to record mandibular lateral movement and chewing movement. Mandibular lateral movement was performed acceding to the method used for Pantographic reproducibility index, and from this, reproducibility index devised by the author and named as BioEGN reproducibility index(BERI) was computed. Chewing movement was observed as to chewing velocity and range of movements.
The data were categorized by the preferred chewing side and the correlationship between reproducibility of mandibular lateral movement and chewing movement was also analyzed with SAS/stat program.
The results obtained were as follows :
1. There were no statistical difference in most of the measurement items of chewing movement according to preferred chewing side, but mean value of some items such as velocity and total lateral distance in horizontal plane in left-side preferred chewing subjects were higher than those in right-side preferred chewing subjects.
2. Reproducibility indexes on lateral movements to both preferred chewing side and contra-lateral side were statistically same in each chewing subjects group.
3. In right-side preferred chewing subjects, correlationship between reproducibility of mandibular lateral movement and chewing movement were significant contralaterally, but in left-side preferred chewing subjects, the correlationship were observed in left-side chewing movement only.
4. In right-side preferred chewing subjects, there was a negative correlationship between reproducibility of mandibular lateral movement and slight mandibular protrusion in early stage of chewing movement, and in left-side preferred chewing subjects, the items of significant correlations with mandibular reproducibility were sagittal mouth opening range and horizontal distance to preferred chewing side.
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