EVIDENCE OF SEX-SPECIFIC DIFFERENCES IN MASTICATORY JAW MOVEMENT PATTERNS

The complexity of human oral functional movements has not been studied in detail quantitatively, and only recently have studies begun to eva luate whether such movements contain sex-specific characteristics. The refore, the purposes of this study were: (1) to quantify in detail the jaw movements and associated masticatory electromyographic activity o ccurring during gum chewing, and (2) to explore these data for evidenc e of sex specificity. Fourteen male and 17 female subjects participate d in the study. Approximately 11 right- and 11 left-sided chewing cycl es and associated masticatory electromyographic activity were sampled from each subject. The samples were quantified into 165 variables per chewing cycle, averaged to create a single multivariate vector for eac h subject, and then analyzed by a step-wise discriminant analysis. Wit h a combination of 6 variables, a jackknifed cross-validation test fou nd the probability of correct classification to be 93.5%. These findin gs support the hypothesis that masticatory jaw movements contain sex-s pecific features.