title: Periodontal health of palatally displaced canines treated with open or closed surgical technique: a multicenter, randomized controlled trial.
abstract: BACKGROUND
  The aim of this study was to investigate differences in the periodontal outcomes of palatally displaced canines (PDC) exposed with either an open or a closed surgical technique.
  
  
  METHODS
  A multicenter, randomized controlled trial was undertaken in 3 hospitals in the United Kingdom, involving 2 parallel groups. Patients with unilateral PDC were randomly allocated to receive either an open or a closed surgical exposure. Periodontal health was assessed 3 months after removal of fixed appliances. Parameters measured included clinical attachment levels, recession, alveolar bone levels, and clinical crown height.
  
  
  RESULTS
  Data from 62 participants (closed, 29; open, 33) were analyzed. There was no difference between PDC exposed with an open vs a closed surgical technique (mean difference, 0.1 mm; 95% confidence interval [CI], -0.2-0.5). There was, however, a statistical difference in mean attachment loss between the operated and unoperated (contralateral) canines (mean difference, 0.5 mm; 96% CI, 0.4-0.7; P <0.001). Twenty of the 62 subjects had some recession on the palatal aspect of the operated canine, whereas only 4 subjects had some visible root surface on the palatal aspect on the unoperated side (P = 0.001).
  
  
  CONCLUSIONS
  There is a periodontal impact when a unilateral PDC is exposed and aligned. This impact is small and unlikely to have clinical relevance in the short term; however, the long-term significance is unknown. When the open and closed techniques were compared, no difference in periodontal health was found.
authors.affiliation: Charles Clifford Dental Hospital, Sheffield, United Kingdom.
authors.forename: Nicola A
authors.initials: NA
authors.lastname: Parkin
authors.forename: Richard S
authors.initials: RS
authors.lastname: Milner
authors.forename: Chris
authors.initials: C
authors.lastname: Deery
authors.forename: David
authors.initials: D
authors.lastname: Tinsley
authors.forename: Anne-Marie
authors.initials: AM
authors.lastname: Smith
authors.forename: Peter
authors.initials: P
authors.lastname: Germain
authors.forename: Jennifer V
authors.initials: JV
authors.lastname: Freeman
authors.forename: Sarah J
authors.initials: SJ
authors.lastname: Bell
authors.forename: Philip E
authors.initials: PE
authors.lastname: Benson
mesh_terms: D000293:Adolescent; D000539:Alveolar Process / Q000473:pathology; D003481:Cuspid / Q000473:pathology*; D005260:Female; D005500:Follow-Up Studies; D005889:Gingival Recession / Q000145:classification; D006801:Humans; D008297:Male; D009061:Mouth Mucosa / Q000473:pathology / Q000601:surgery; D016910:Orthodontic Brackets; D010159:Palate / Q000473:pathology / Q000601:surgery; D017622:Periodontal Attachment Loss / Q000145:classification; D010512:Periodontal Index; D016300:Radiography, Bitewing; D019237:Tooth Cervix / Q000473:pathology; D019228:Tooth Crown / Q000473:pathology; D014079:Tooth Eruption, Ectopic / Q000601:surgery; D014087:Tooth Movement Techniques / Q000295:instrumentation / Q000379:methods*; D014095:Tooth, Impacted / Q000601:surgery*; D016896:Treatment Outcome