A Clinical Investigation On External Apical Root Resorption Of Incisors After Fixed Orthodontic

Root resorption is defined as an absorption leading to loss of cementum or dentine pathological or physiological process, with the result as shorter root and blunting root apical. With a complex mechanism, the true etiology and pathogenesis have so far not fully aware of. With the wide range of fixed orthodontic treatment carried out, root resorption during orthodontic treatment as a common complication attracts more and more attention. Therefore, we conducted a preliminary study to investigate the relationship between root resorption related to fixed appliance and the variables including sex, age and so on, with a view to play a guiding role in future research and clinical work for the orthodontic physicians and provide a scientific basis for detailed help.PURPOSE:To investigate the relationship between root resorption related to fixed appliance and the variables including sex, age, teeth extraction, type of malocclusion and treatment course.METHODS:90 patients were divided into 2 groups according to age:juvenile group and adult group. Measure and calculate the average amount of the incisor root resorption before and after treatment, with this value to represent the value of statistical. Re-classify the groups according to statistical data with the needs of various research factors, and paired t test and multiple analysis of variance were induced respectively. Analyze the relationship between root resorption related to fixed appliance and the variables including sex, age, teeth extraction, type of malocclusion and treatment course.RESULTS:1.Root absorption occurred in every patient. There was no significant difference between the same-age groups of males and females (P＜0.001); However, there was significant difference between adult groups (both males and females) and juvenile groups (P＜0.01).2.There was significant difference between extracted groups and unextracted groups(P＜0.01).3.AngleⅡmalocclusion has a great effect on root resorption(P＜0.01).However, the other two kinds of deformity did not found significant statistically different results(P>0.05).4.1n a certain period of time, the amount of root resorption increased with the treatment, but in the latter period, the root absorption remained basically unchanged.CONCLUSION:The incisal root resorption occurs in every fixed-appliance case. The root absorption caused by fixed-appliance has no significant correlation with sex; however, absorption of adult groups is of higher level than that of juvenile groups. Teeth extraction, AngleⅡmalocclusion and treatment course can all promote root resorption.