A comparision of the effects of closing the prolonged and fresh space of molar extraction on root resorption
HAN Jian-li,LIU Jin,GUO Xin,GE Yuan-shu.Department of Orthodontics.Shenzhen Children's Hospital.Shenzhen 518026,China
Objective:To investigate the influence of different molar extraction time on apical root resorption during orthodontic space closure treatment and to see if the longer the extraction time of first molar the more serious root resorption of second molar will occur during orthodontic space closure treatment.Method:25 subjects who had undergone mandibular first molar extraction were selected and divided into two groups according to the different molar extraction time. The apical resorption of mandibular second molars was measured on panoramic radiographys before and after treatment.Result: There were statistically significant differences in root resorption between pretreatment and posttreatment. However there seemed no statistically significant between groups no matter how long the molar has been extracted. Conclusion:Orthodontic treatment of closing the prolonged molar extracton space couldn't aggravated the root resorption of molars.