Piezocision-assisted orthodontic treatment using CAD/CAM customized orthodontic appliances: a randomized controlled trial in adults

Objective: The aim of this study was to investigate the effects of piezocision (surgical protocol with sutures) in orthodontic treatment using CAD/CAM (computer-aided design and computer-aided manufacturing) customized orthodontic appliances. Design: The study is designed as a parallel group, randomized controlled trial (RCT). Setting: University Hospital. Ethical approval: The study was approved by the ethic committee of the University Hospital Liege, Belgium. Subjects and methods: This RCT was conducted on 24 adult patients requiring orthodontic treatment to release mild overcrowding. Patients were all treated with a customized appliance and randomly assigned by means of sealed envelopes containing group codes to either a test group treated with piezocision or a control group without any further treatment. A blinded orthodontist validated appliance removal or further adjustments based on the model study. Outcome measures: The overall treatment time and the time between archwire changes were recorded. Moreover, clinical and radiological features such as tooth resorption, gingival recessions, and the presence of scars were evaluated. Results: A total of 24 patients (12 control and 12 test) completed the study. The overall treatment time was significantly shorter in the test group than the control group. Likewise, the time difference between all arch changes was significantly lower when piezocision was performed, except for the first arch at the mandible and the last arches at both maxillae. During the fine-tuning phase, no significant difference was found between the two groups. All periodontal and radiographic parameters remained stable from the start to the end of treatment in both the groups. However, minor scars were found in 66 per cent cases. Limitations: This trial was a single-centre trial. Conclusions: Piezocision seems to be an effective method to accelerate orthodontic treatment in cases of mild overcrowding. However, the effect was only observed during the alignment phase and a greater efficiency was found in the maxilla. The technique may be contraindicated in patients with a high smile line since the risk of slight scarring exists.