Comparative study on masticatory efficiency of 7～9 year-olds with primary molar defect before and after treatment

Objective To study the change of masticatory efficiency in 7～9 year-olds with primary molar defect after treatment.Methods We selected three groups of 7～9 year-olds:normal mixed dentition, primary molar defect before and after treatment, and primary molars loss.There were 36 subjects in each group.Then we measured the semi-minute masticatory efficiency of each subject by light absorption method.Results The masticatory efficiency of the primary molar defect group after treatment was significantly higher than that of the group before treatment(P0.001). No significant difference was found between the masticatory efficiency of the primary molar defect group after treatment and that of normal occlusal children(P0.05). The masticatory efficiency after treatment of one-side or two-side primary molar defect group was significantly higher than that of the group before treatment(P0.05). The masticatory efficiency after treatment of one or more than one primary molar defect group was significantly higher than that of the group before treatment(P0.05). Conclusion The masticatory efficiency of the primary molar defect group may increase significantly after treatment, and it may restore to the normal standard after treatment.