Alfonso Navarrete DDS; Greg Huang DMD, MSD, MPH
There is limited evidence to support the use of osseointegrated palatal implants to reinforce anchorage in orthodontic treatment.
In patients requiring anchorage for orthodontic treatment, does surgically assisted anchorage compared to traditional anchorage methods result in equivalent tooth movement?
The authors conducted a search of 4 electronic databases in all languages spanning 1966 to February 1, 2006. The inclusion criteria were: a) randomized or quasi-randomized controlled trials; b) subjects of all ages; and c) the use of surgically assisted anchorage reinforcement techniques. Two individuals independently reviewed studies for inclusion criteria, abstracted the data, and assessed the quality of the studies. They measured outcomes using parameters such as a change in overjet and the distances over which teeth moved.
The authors identified 157 articles from the initial search, none of which meet the inclusion criteria. However, while conducting their review the authors identified 1 trial that met the inclusion criteria. In this study, 51 subjects were aged 12 through 39 years and had a Class II Division 1 malocclusion with absolute anchorage requirements. Subjects were randomly allocated to either a headgear or a midpalatal implant group. Anchorage loss was measured cephalometrically. The headgear group showed more mesial movement of dental and skeletal reference points than the midpalatal implant group. The mean difference of 1.55mm between groups was not statistically significant.
The authors concluded that there is limited evidence that midpalatal implants are an acceptable alternative to headgear in reinforcing anchorage in terms of resultant tooth movement. There is little evidence concerning other surgically assisted anchorage techniques. Likewise, there is limited evidence addressing factors such as patient acceptance, discomfort, economic concerns, and failure rates.
Source of Funding:
School of Clinical Dentistry & Clifford Dental Hospital, University of Sheffield, UK.
Importance and Context:
The ability to control anchorage during orthodontic treatment is important in preventing unwanted tooth movement. Extraoral headgear traditionally has been used but has been limited by patient compliance/acceptance. This review summarizes the literature on using surgical methods to reinforce orthodontic anchorage.
Strengths and Weaknesses of the Systematic Review:
The review was thorough. The authors searched 4 databases without language restrictions and handsearched journals and reference lists. They stated the inclusion criteria and provided lists of included and excluded studies. Two independent reviewers assessed studies for inclusion, abstracted data and judged the quality of the included studies. This systematic review included only 1 study, which was written by 1 of the review authors. However, this author was not involved in the quality assessment of this trial.
Strengths and Weaknesses of the Evidence:
Much of the research on surgical anchorage is still developing. While the 1 study included showed that osseointegrated palatal implants effectively reinforce anchorage, it did not address other prevalent skeletal anchorage methods, many of which rely on mechanical stability for retention.
Implications for Dental Practice:
There is limited evidence to support using osseointegrated palatal implants to reinforce orthodontic anchorage requirements. However, it is important that the clinician be able to distinguish between the different types of surgical anchorages. For example, newer techniques involve the use of miniscrews that rely on mechanical retention for immediate loading. REFERNCES  Benson PE, Tinsley D, O’Dwyer JJ, Majumdar A, Doyle P, Sandler PJ. Midpalatal implants vs headgear for orthodontic anchorage – a randomized clinical trial: Cephalometric results. Am J Orthod Dentofacial Orthop. 2007 Nov; 132(5): 606-615.