title: Influence of Preadjusted Bracket Shape and Positioning Reference on Angulation of Upper Central Incisor.
abstract: OBJECTIVE
  To verify the influence of different bracket shapes and placement references according to Andrews and MBT systems on the expression of angulation in upper central incisors (UCI).
  
  
  METHODS
  Bracket positioning and mesiodistal dental movement simulations were performed and the angulations produced in the dental crown were evaluated, based on computed tomography scan images of 30 UCI and AutoCAD software analysis. Rectangular (Andrews) and rhomboid (MBT) brackets were placed according to the references recommended by Andrews and MBT systems - long axis of the clinical crown (LACC) and incisal edge (IE) respectively.
  
  
  RESULTS
  Data showed that the use of LACC as reference for bracket positioning produced 5° and 4° UCI angulations in Andrews and MBT brackets respectively. The use of IE produced a 1.2° mean angulation in UCI for both brackets.
  
  
  CONCLUSIONS
  When the LACC was used as reference for bracket positioning, the UCI crown angulation corresponded to the angulation built into the brackets, regardless of shape, while the use of IE resulted in natural crown angulation, regardless of bracket shape.
  
  
  CONCLUSIONS
  This research contributes to guide the orthodontist in relation to the different treatment techniques based on the use of preadjusted brackets.
authors: Department of Pediatric and Community Dentistry, Dental School of Araçatuba, Universidade Estadual Paulista - UNESP (São Paulo State University), Araçatuba, São Paulo, Brazil, e-mail: frantopolski@gmail.com.
authors: Francielle
authors: F
authors: Topolski
authors: Private Practice, Paraná, Brazil.
authors: Mauricio A
authors: MA
authors: de O Accorsi
authors: Private Practice, São Paulo, Brazil.
authors: Hugo J
authors: HJ
authors: Trevisi
authors: Department of Pediatric and Community Dentistry, Dental School of Araçatuba, Universidade Estadual Paulista - UNESP (São Paulo State University), Araçatuba, São Paulo, Brazil.
authors: Osmar A
authors: OA
authors: Cuoghi
authors: Department of Restorative Dentistry, Universidade Federal do Paraná - UFPR (Federal University of Paraná), Curitiba Paraná, Brazil.
authors: Ricardo
authors: R
authors: Moresca
mesh_terms: D003198:Computer Simulation; D017076:Computer-Aided Design; D006801:Humans; D007180:Incisor / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D003765:Models, Dental; D016382:Orthodontic Appliance Design; D016910:Orthodontic Brackets; D011861:Radiography, Dental; D019228:Tooth Crown / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D014087:Tooth Movement Techniques
keywords: Orthodontic brackets; Orthodontics; Straight wire; Tooth angulation Tooth movement.