Open versus closed exposure of palatally displaced canines : a randomised clinical trial

• Main Author: Parkin, Nicola Ann
• Format: Dissertation
• Language: English
• Published: University of Sheffield 2012

Purpose: To investigate the differences in outcomes between Open and Closed exposures of PDC. The primary outcome assessed is periodontal health; secondary outcome measures include economics and patient response. Methods: A multicentre randomised controlled trial involving two parallel groups. The settings were one dental teaching hospital (Charles Clifford Dental Hospital, Sheffield) and two regional peripheral hospital units. Individuals aged under 20 years with unilateral PDC were identified as potential participants using specific inclusion and exclusion criteria. Those patients or their parents who gave informed consent to take part in the study were randomly allocated to either receive the Open or Closed surgical procedure. Periodontal outcomes included Clinical attachment levels, gingival recession, crown height and aesthetic ratings (judqed by orthodontists and lay persons). Economic outcomes were calculated from information given from Trust Accountants, length of time spent in the operating theatre and number of visits required to complete orthodontic treatment. Patient response was assessed using a 10 day post-operative questionnaire. Results: Eighty-one participants were enrolled (Closed = 41, Open =40). Ten patients did not receive palatal surgery (Closed = 5, Open = 5) therefore the maximum number of participants in any analysis was 71. The results of each outcome measure have been summarised according to the order of data collection. Theatre times were obtained from 57 out of the 71 participants who underwent surgery (Closed 26, Open 31). The mean surgical time was virtually identical between the two groups (Closed 34.3 mins, SD 11.9; Open 34.3 mins, SD 11.2), which was not statistically different (independent t test; P = 0.986). There were no differences in number of orthodontic visits required to move the PDC into the line of the arch (P= 0.516) nor were there any differences in cost to the NHS according to the HRG4 2011/12 Report. There were no significant differences between the Closed and Open groups for any of the patient reported outcomes.Difficulty brushing was the most frequently reported impact on every day activities. In terms of pain, the majority of the responses (36 out of 60) claimed that post-operative pain lasted for several days but less than a week. In terms of the primary outcome measure, the periodontal outcome, statistical differences were found in six point clinical attachment levels between the treated canine and the untreated contra-lateral canine. The mean difference was = 0.6mm, P=0.001. However, no differences were found when Closed and Open groups were compared (P=0.782). For the other periodontal parameters measured, including the aesthetic analysis, no differences were found between Closed and Open groups. Conclusions: There were no differences in any of the outcomes investigated in this study between Closed and Open surgical techniques for PDC.