title: [Correlation study between sex and age of patients and root resorption after orthodontic treatment].
abstract: OBJECTIVE
  To investigate the relationship between root resorption related to fixed appliance and the variables including sex, age.
  
  
  METHODS
  44 patients were divided into four groups according to sex and age: juvenile males, juvenile females, adult males, adult females. The length of incisors was calculated according to orthopantomograph and study models of pre- and post-treatment, and the relationship between patients' sex and age and root absorption pre- and post-treatment was analyzed by paired t test.
  
  
  RESULTS
  Root absorption occurred in every patient. There was no significant difference between the same-age groups of males and females (P<0.05); However, there was significant difference between adult groups (both males and females) and juvenile groups (P<0.01).
  
  
  CONCLUSIONS
  Root absorption occurs in every fixed-appliance case. Fixed-appliance-caused root absorption has no significant correlation with sex;however, absorption of adult groups is of higher level than that of juvenile groups.
authors.affiliation: Department of Orthodontics, School of Stomatology, Shandong University, Jinan 250012, Shandong Province, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Zhang
authors.forename: Wen-juan
authors.initials: WJ
authors.lastname: Zhang
authors.forename: Xu-xia
authors.initials: XX
authors.lastname: Wang
authors.forename: Shi-liang
authors.initials: SL
authors.lastname: Ma
authors.forename: Dai-yun
authors.initials: DY
authors.lastname: Chen
mesh_terms: D000293:Adolescent; D000328:Adult; D005260:Female; D006801:Humans; D007180:Incisor; D008297:Male; D009967:Orthodontic Appliances; D011862:Radiography, Panoramic; D012391:Root Resorption; D014092:Tooth Root