title: Root resorption during orthodontic treatment with self-ligating or conventional brackets: a systematic review and meta-analysis.
abstract: BACKGROUND
  The aim of this study was to compare the external apical root resorption (EARR) in patients receiving fixed orthodontic treatment with self-ligating or conventional brackets.
  
  
  METHODS
  Studies comparing the EARR between orthodontic patients using self-ligating or conventional brackets were identified through electronic search in databases including CENTRAL, PubMed, EMBASE, China National Knowledge Infrastructure (CNKI) and SIGLE, and manual search in relevant journals and reference lists of the included studies until Apr 2016. The extraction of data and risk of bias evaluation were conducted by two investigators independently. The original outcome underwent statistical pooling by using Review Manager 5.
  
  
  RESULTS
  Seven studies were included in the systematic review, out of which, five studies were statistically pooled in meta-analysis. The value of EARR of maxillary central incisors in the self-ligating bracket group was significantly lower than that in the conventional bracket group (SMD -0.31; 95% CI: -0.60--0.01). No significant differences in other incisors were observed between self-ligating and conventional brackets.
  
  
  CONCLUSIONS
  Current evidences suggest self-ligating brackets do not outperform conventional brackets in reducing the EARR in maxillary lateral incisors, mandible central incisors and mandible lateral incisors. However, self-ligating brackets appear to have an advantage in protecting maxillary central incisor from EARR, which still needs to be confirmed by more high-quality studies.
authors.affiliation: Department of Orthodontics, State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, #14, 3rd Section, South Renmin Road, Chengdu, 610041, People's Republic of China.
authors.forename: Jianru
authors.initials: J
authors.lastname: Yi
authors.affiliation: Department of Orthodontics, State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, #14, 3rd Section, South Renmin Road, Chengdu, 610041, People's Republic of China.
authors.forename: Meile
authors.initials: M
authors.lastname: Li
authors.affiliation: Department of Orthodontics, State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, #14, 3rd Section, South Renmin Road, Chengdu, 610041, People's Republic of China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Li
authors.affiliation: Department of Pediatric Dentistry, State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, China.
authors.forename: Xiaobing
authors.initials: X
authors.lastname: Li
authors.affiliation: Department of Orthodontics, State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, #14, 3rd Section, South Renmin Road, Chengdu, 610041, People's Republic of China. zhzhao@scu.edu.cn.
authors.forename: Zhihe
authors.initials: Z
authors.lastname: Zhao
mesh_terms: D006801:Humans; D007180:Incisor; D016382:Orthodontic Appliance Design; D016910:Orthodontic Brackets; D009969:Orthodontic Wires; D012391:Root Resorption
keywords: Conventional bracket; Root resorption; Self-ligating bracket; Systematic review