title: An in vivo study on the incidence and location of fracture in round orthodontic archwires.
abstract: OBJECTIVE
  The main objective of this in vivo study was to determine the incidence and location of fracture in round nickel-titanium (NiTi) and round stainless steel orthodontic archwires, both commonly used in orthodontics. Secondarily, this study sought to determine if there is any correlation between archwire fracture and gender, diameter of the archwire, arch type (maxillary/mandibular) or bracket used.
  
  
  METHODS
  In vivo study.
  
  
  METHODS
  One thousand orthodontic patients (1434 archwires) were evaluated during regular treatment visits to assess archwire fracture and location. The patient's gender, age, type of archwire (round NiTi and round stainless steel), diameter of the archwire, arch type, location of fracture (anterior or posterior) and period of service before fracture were recorded.
  
  
  METHODS
  Chi-square statistical test was utilized to address the frequency and the correlation between the different variables. Level of statistical significance (α) was set at 0.05.
  
  
  RESULTS
  Twenty-five archwire failures were reported (1.7%) of the total sample size. All fractured archwires were NiTi, and 76% of the fractures were located in the posterior region. No statistical significance was found between archwire fracture and gender, arch type (maxillary/mandibular), archwire diameter or bracket type.
  
  
  CONCLUSIONS
  The frequency of archwire fracture during regular orthodontic visits is very low. The most common archwire fracture site is the posterior region. NiTi wires are the most commonly fractured archwire. No statistically significant correlation exists between archwire fracture and gender, arch type, bracket type or diameter of archwire.
authors.affiliation: A. Abdelkarim, University of Mississippi School of Dentistry, 2500 N. State Street, Jackson, MS 39216, USA. ahmadozbrain@yahoo.com.
authors.forename: Ulises
authors.initials: U
authors.lastname: Guzman
authors.forename: Laurance
authors.initials: L
authors.lastname: Jerrold
authors.forename: Ahmad
authors.initials: A
authors.lastname: Abdelkarim
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D003722:Dental Alloys / Q000737:chemistry; D003724:Dental Arch; D004868:Equipment Failure / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D008297:Male; D008310:Malocclusion / Q000145:classification; D008875:Middle Aged; D009532:Nickel / Q000737:chemistry; D016382:Orthodontic Appliance Design / Q000706:statistics & numerical data; D016910:Orthodontic Brackets; D009969:Orthodontic Wires / Q000706:statistics & numerical data*; D012737:Sex Factors; D013193:Stainless Steel / Q000737:chemistry; D013499:Surface Properties; D013997:Time Factors; D014025:Titanium / Q000737:chemistry; D055815:Young Adult
chemical_list: D003722:Dental Alloys; C040654:titanium nickelide; D013193:Stainless Steel; D009532:Nickel; D014025:Titanium
keywords: Incidence of archwire fracture; an in vivo study; incidence and location of wire fracture; location of archwire fracture