Greg Huang DMD, MSD, MPH; Jeff Hyde DDS
Evidence indicates that early orthopedic correction of Class III malocclusion is successful, but further studies are needed to assess long-term results.
Is early orthopedic treatment of Class III malocclusion effective?
The authors conducted an English-only search of the PubMed database from January 1, 1966 through December 2005. They also searched the Cochrane Controlled Clinical Trials Register. The inclusion criteria were 1) randomized or controlled prospective or retrospective clinical trials with controls; 2) growing patients; 3) use of lateral cephalograms. The outcomes assessed included obtaining a positive overjet, Class I molar relationship, or both. Treatment approaches and length of treatment varied. Two independent reviewers assessed the studies.
The authors identified 536 articles in the initial search, of which 19 studies met the inclusion criteria. One of these was a randomized clinical trial and the other 18 were controlled clinical trials. The authors excluded case reports, opinion articles, reports on adults, and reports on patients for which no cephalometric analyses were done. A quality evaluation of the included articles revealed a mix of low, medium, and medium-high quality studies. Treatment modalities included chin-cup, facemask therapy, facemask with RME, Bionator III, FR-3, maxillary protractor bow, double-plate appliance, and mandibular headgear. Total active orthopedic treatment time ranged from 6 months to more than 3 years, and follow-up observation and/or fixed appliance treatment time ranged from 6 months to more than 5 years. Success rates for correction of the Class III malocclusion ranged from 76% to 100%, with decreasing skeletal correction and increasing dental correction as the age of subjects increased. Side effects of treatment included retroclination of mandibular incisors and proclination of maxillary incisors.
The reviewers concluded that orthopedic treatment of Class III malocclusions in children is effective when assessed up to 5 years post-treatment. However, even after 5 years, these patients (especially males) may have considerable facial growth remaining, and longer-term RCT’s on the effects of different orthopedic treatment modalities are needed.
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Importance and Context:
Although affecting only a small segment of the population, Class III malocclusion is an important orthodontic concern due to the potential need for surgical correction after cessation of growth. Orthopedic intervention can be performed during the mixed dentition, and appears to be effective. However, questions remain regarding the preferred method of orthopedic correction, as well as the long-term effectiveness and stability of these treatments.
Strengths and Weaknesses of the Systematic Review:
Although the authors used 2 independent reviewers and employed methodological critiques of each included article, their review was not exhaustive. The search was limited to 2 databases and 1 language; and there was no mention of searching reference lists, gray literature, or contacting authors. Additionally, the authors stated they searched for meta-analyses but did not mention 2 previously published meta-analyses on Class III orthopedic treatment.(1,2)
Strengths and Weaknesses of the Evidence:
The authors acknowledge the limitations of the current literature, such as failure to report success rates, minimal long-term follow-up, and inappropriate statistical analyses. Only 1 randomized controlled trial on Class III orthopedic intervention is known to have been published.(3) Despite these weaknesses, all 19 included studies showed improvement in the jaw relationship. Additionally, the 2 meta-analyses that have previously been conducted on orthopedic treatment of Class III malocclusion report findings that are consistent with this systematic review.
Implications for Dental Practice:
Current evidence provides clear support for the effectiveness of early orthopedic intervention to treat a Class III malocclusions. However, more definitive trials with observation at the end of skeletal growth are needed to determine if the correction is stable. An ultimate goal would be the ability to predict which Class III patients would receive the most benefit from early orthopedic therapy, and in which patients this correction is likely to be maintained.
 Kim JH, Viana M, Graber TM, Omerza FF, BeGole EA. The effectiveness of protraction face mask therapy: A meta-analysis. Am J Orthod Dentofacial Orthop. 1999; 115:675-85.
 Jager A, Braumann B, Kim C, Wahner S. Skeletal and dental effects of maxillary protraction in patients with angle class III malocclusion: A Meta-Analysis. J Oro Orthop 2001; 62:275-84.
 Vaughn GA, Mason B, Moon HB, Turley PK. The effects of maxillary protraction therapy with or without rapid palatal expansion: a prospective, randomized clinical trial. Am J Orthod Dentofacial Orthop. 2000; 118:335-340.