title: Magnitude and reproducibility of forces generated by clinicians during laceback placement.
abstract: OBJECTIVE
  To determine the magnitude and reproducibility of forces generated by clinicians during laceback placement using a force-measuring typodont.
  
  
  METHODS
  An in vitro investigation.
  
  
  METHODS
  An in vitro typodont model was developed, which incorporated strain gauges attached to a personal computer to allow measurement of the force generated on application of lacebacks. Ten operators were instructed to place lacebacks five times, on two separate occasions (T1 and T2). Inter-operator and intra-operator forces produced at T1 and T2 were compared.
  
  
  METHODS
  Forces generated by laceback placement.
  
  
  RESULTS
  The forces generated by clinicians ranged from 0 to 11.1 N. There were significant differences in the mean forces generated by the different operators (P < 0.001), with differences between time points not being consistent across all operators (P < 0.001). Some operators were more consistent than others in the forces generated.
  
  
  CONCLUSIONS
  In vitro, there was a large inter-operator variation in the forces produced during laceback placement. With the in vitro model used in this study, few operators applied similar forces when placing lacebacks on two separate occasions.
authors.affiliation: Unit of Orthodontics, Glasgow Dental School, 378 Sauchiehall Street, Glasgow, G2 3JZ, UK. bkhambay@yahoo.com
authors.forename: B S
authors.initials: BS
authors.lastname: Khambay
authors.forename: S
authors.initials: S
authors.lastname: McHugh
authors.forename: D T
authors.initials: DT
authors.lastname: Millett
mesh_terms: D000704:Analysis of Variance; D003481:Cuspid; D003799:Dental Stress Analysis; D006801:Humans; D008334:Mandible; D003765:Models, Dental; D009967:Orthodontic Appliances; D019516:Orthodontic Space Closure / Q000295:instrumentation; D015203:Reproducibility of Results; D014087:Tooth Movement Techniques / Q000295:instrumentation