The Correlation Between 7-year-old To 9-year-old Children's Masticatory Efficiency, Occlusal Contact Area And Primary Molars Defect Or Loss

Masticatory function is the important physiologic function of oral cavity. Nowadays, with the increasing incidence rate of dental caries, malocclusion and temporomandibular joint disturbance syndrome, masticatory efficiency of children and juvenile is significantly decreasing which draws great attention in stomatology. So the study of masticatory efficiency and its important influential factors has very important clinical meaning. The purpose of the study is to research the correlation between masticatory efficiency, occlusal contact area and primary molars defect or loss , to study the effect of primary molars defect or loss on masticatory efficiency,to guide the treatment of dens and dentition defect,to evaluate the effect of treatment.The study includes three parts as follows:Part one: A Study of correlation between masticatory efficiency and occlusal contact area in 7-year-old to 9-year-old childrenObjective: To measure masticatory efficiency and occlusal contact area of normal occlusion in 7-year-old to 9-year-old children, to analyze the correlation between masticatory efficiency and sex, occlusal contact area.Methods: Roasted peanuts were used as the test materials to measure the semi-minute masticatory efficiency of normal occlusion in 7-year-old to 9-year-old children with absorption method. To measure occlusal contact area in intercuspal position (ICP) of normalocclusion in 7-year-old to 9-year-old children with T-scan system(produced by American Tekscan co.). SPSS 11.0 statistical software was used to analyze the correlation between masticatory efficiency and occlusal contact area .Result: No Significant difference was found between male group and female group of masticatory efficiency and occlusal contact area in 7-year-old to 9-year-old children with normal occlusion (P>0.05). There was no Significant difference between left side and right side of occlusal contact area in 7-year-old to 9-year-old children with normal occlusion (P>0.05). There was significant positive correlation between masticatory efficiency and occlusal contact area in 7-year-old to 9-year-old children with normal occlusion (P<0.001).Conclusion: The sex does not influence masticatory efficiency and occlusal contact area in 7-year-old to 9-year-old children with normal occlusion. Their occlusal contact area is balance between left and right side. Occlusal contact area has important effect on masticatory efficiency. We should renew occlusal contact area to maintain masticatory efficiency in 7-year-old to 9-year-old children with primary molars defect or loss.Part two: A study on the masticatory efficiency in 7-year-old to 9-year-old children with primary molars defect or loss Objective: To study the effect of primary molars defect or loss on masticatory efficiency in 7-year-old to 9-year-old children.Methods: To measure the masticatory efficiency of 7-year-old to 9-year-old children with primary molars defect or loss by light absorbtion method.Result: The masticatory efficiency of primary molars defect group was significantly lower than that of normal group(P<0.05),the ratio of the former to the latter was only 76.04%. The masticatory efficiency ofprimary molars loss group was significantly lower than that of normal group(P<0.001), the ratio of the former to the latter was only 67.91%. There was no significant difference between primary molars loss group and primary molars defect group (P>0.05) The masticatory efficiency of one side primary molars defect or loss was significantly higher than that of two side primary molars defect or loss group normal group(P<0.05). The masticatory efficiency of one tooth primary molars defect or loss was significantly higher than that of more than one tooth primary molars defect or loss group normal group(P<0.05).Conclusion: Primary molars defect or loss have a significant influence in masticatory efficiency in 7-9 years children. The patients must be treated in time.If residual root or crown could not be well treated ,they should be pulled out in time.Part three : A study of the comparement between the masticatory efficiency of primary molars defect group after treatment and that of the group before treatmentObjective: To study the change of masticatory efficiency after treatment in 7-year-old to 9-year-old children with primary molars defect.Methods: To measure the masticatory efficiency after treatment in 7-year-old to 9-year-old children with primary molars defect by light absorbtion method .To analyze the difference among the masticatory efficiency of primary molars defect group after treatment, that of the group before treatment and that of normal occlusal children with SPSS 11.0 statistical software.Result: The masticatory efficiency of primary molars defect group after treatment was significantly higher than that of the group before treatment (P<0.001). No Significant difference was found between the masticatory efficiency of primary molars defect group after...