Is anchorage reinforcement with implants effective in orthodontics?

Abstract

The Cochrane Oral Health Group's Trials Register, Cochrane Central Register of Controlled Trials (CENTRAL), Medline and Embase were searched. No language restrictions were applied. Authors were identified and contacted to identify unpublished trials. Studies selected were randomised clinical trials (RCT) or quasi-RCT involving surgically assisted means of anchorage reinforcement in orthodontic patients. Data extraction was performed by two review authors working independently using a previously piloted data collection form. Data were entered into RevMan (The Nordic Cochrane Centre. Copenhagen, Denmark); planned analysis of mean differences and 95% confidence intervals (CI) for continuous outcomes, and risk ratios (RR) and 95% CI for dichotomous outcomes. Pooling of data and meta-analysis were not performed because there were too few similar studies. To date, few trials have been carried out in this field and there are insufficient data of adequate quality in the literature to meet the objectives of the review. The review authors were only able to find one study that assessed the use of surgical anchorage reinforcement systems. This trial examined 51 patients with absolute anchorage requirements treated in two centres. Patients were randomly allocated to receive either headgear or a midpalatal osseo-integrated implant. Anchorage loss was measured cephalometrically by mesial movement of dental and skeletal reference points between the start of treatment and the end of anchorage reinforcement. All skeletal and dental points moved mesially more in the headgear group than the implant group. Results showed significant differences for mesial movement of the maxillary molar in both groups. The mean change in the implant group was 1.5 mm [standard deviation (SD), 2.6; 95% CI, 0.4-2.7] and for the headgear group was 3.0 mm (SD, 3.4; 95% CI, 1.6-4.5). The trial was designed to test a clinically significant difference of 2 mm, so the result was not statistically significant, but the authors conclude that midpalatal implants do effectively reinforce anchorage and are an acceptable alternative to headgear in absolute anchorage cases. There is limited evidence that osseo-integrated palatal implants are an acceptable means of reinforcing anchorage. The review authors were unable to identify trials addressing the secondary objectives of the review relating to patient acceptance, discomfort and failure rates. In view of the fact that this is a dynamic area of orthodontic practice, there is a need for high-quality RCT. There are financial restrictions in running trials of this nature but it would be in the interest of implant manufacturers to fund such quality, independently conducted trials of their products.