A Study On Bite Force And Electromyography Of Masticatory Muscles In Unilateral Masticators

Objective:Tee Tester digital occlusal analysis system and Keypoint emg/evoked potentiometer were used to collect data such as bite force,myoelectric activity asymmetry index of masseter and temporalis anterior tract of unilateral masticators and normal masticator in the interlacing position.To study the changes of occlusal parameters and emg amplitude of masseter and temporalis muscle in masticatory side and non-masticatory side of unilateral masticators in interlacing position,so as to provide theoretical basis for intervention of chewing-side preference..Methods:1.Select subjects and equipment.According to the questionnaire,22 qualified unilateral masticators and 22 normal masticators were selected from the students of Shanxi medical university and the Second hospital of shanxi medical university.2.Keypoint emg/induced potentiometer was used to determine the myoelectric amplitude of the bilateral musculi masseter(MM)and temporal anterior(TA)of the subject’s teeth when the teeth were clenched in staggered position.Tee Tester V3.2.0 bite force analyzer was used to determine the bite force data of the subjects during occlusion from mandibular postural position(MPP)to Intercuspal position(ICP),and record and save the data.Rest for 3min after each muscle test until another muscle test starts..3.Collect data.The occlusal area of the whole arch was recorded when the proportion of the total arch bite force of the subject was 25%,50% and 75%,and the proportion of bilateral bite force was calculated and the asymmetric index of bilateral bite force was calculated.Asymmetrical indices of emg activity of bilateral TA and MM.4.Statistical analysis.The occlusal parameters and emg information of the CSP group and the normalcontrol group were analyzed by paired t test,while the occlusal data of the CSP group and the normal control group were analyzed by independent sample t test.Results:1.The ratio of bite force in the masticatory side of the CSP group was larger than that in the non-masticatory side,and the difference was statistically significant(p <0.01).2.When the proportion of total dental arch bite force was 75%,the proportion of right bite force in the normal control group was greater than that on the left,and the difference was statistically significant(t=-2.206,p < 0.05).3.The whole teeth bow together accounted for 25%,chewing side bite of CSP group than larger than the normal control group,non mastication side bite accounted for less than the normal control group,there is significant difference statistically significant(p < 0.01),and the overall dental arch 50%,chewing side bite of CSP group than larger than the normal control group,non mastication side bite accounted for less than the normal control group,there are statistically significant difference(p < 0.05),and the overall dental arch 75%,chewing side bite of CSP group than larger than the normal control group,non mastication side bite accounted for less than the normal control group,The difference was not statistically significant(p > 0.05).4.When the proportion of total arch bite force was 25%,the asymmetry index of bite force in the CSP group was greater than that in the normal control group,and the difference was statistically significant(t=3.315,p<0.05),while the difference was not statistically significant at 50% and 75%(p > 0.05).5.There was no statistically significant difference in the asymmetric index of myoelectric activity of the masseter and temporalis anterior tract between the CSP group and the normal control group(p > 0.05).Conclusion:1.Unilateral masticators have asymmetric bilateral bite force,and the masticatory side is larger than the non-masticatory side.When bilateral masticators need to use a large bite force,the phenomenon of unilateral mastication will occur.2.Chewing-side preference had no effect on the symmetry of myoelectric activityof the bilateral masseter muscle and the anterior bundle of the temporalis muscle.