Distraction osteogenesis: little evidence of effectiveness

Maxillary hypoplasia is a common problem in patients with cleft lip and palate. Traditionally this has been managed by single-stage orthognathic surgery. The 1990s saw the development of maxillary distraction osteogenesis and a potential alternative method of surgical correction.

The aim of this review was to compare the effectiveness of distraction osteogenesis to conventional orthognathic surgery for the treatment of maxillary hypoplasia in patients with cleft lip and palate.

Methods

Searches were conducted in the Medline, Embase, Cochrane Central Register of Controlled Trials (CENTRAL), Scopus, Web of Science and Cumulative Index to Nursing and Allied Health Literature (CINAHL), the Current Controlled Trials metaRegister of Controlled Trials, the International Clinical Trials Registry Platform, OpenGrey and WorldCat Dissertations and Index to Theses databases. In addition a 5 relevant journals were handsearched.

Randomised, quasi-randomized and controlled clinical trials comparing distraction osteogenesis with conventional orthognathic surgery published in English were considered. Studies were selected independently by two reviewers with a single reviewer abstracting the data and assessing quality using the Cochrane risk of bias tool.

Results

5 articles reporting different outcomes of a single trial were included.
The individual articles were all considered to be at high risk of bias.
Both surgical interventions produce significant soft tissue improvement. Horizontal relapse of the maxilla was statistically significantly greater following orthognathic surgery.
There was no statistically significant difference in speech and velopharyngeal function between the interventions.
Maxillary distraction initially lowered social self-esteem, but this improved with time resulting in higher satisfaction with life in the long term.

Conclusions

The authors concluded

there is weak evidence that the effectiveness of distraction osteogenesis and conventional osteotomy for the treatment of cleft-related maxillary hypoplasia may differ for certain outcomes. The publications included within this review found that horizontal skeletal stability was improved following internal maxillary distraction. In addition whilst there may be an initial fall in self-confidence and self-esteem with this form of surgical correction, it improves with time. The evidence included within this review however must be interpreted with caution given the limited and relatively low quality and potential bias of the publications.

Commentary

The authors have conducted an extensive database search although restricting the language to English may have excluded some potential studies. In the discussion the authors indicate that they identified 52 foreign language studies, the majority of which (49) would have been excluded by title alone leaving a possibility that 3 could have been included. Although 5 publications were identified these all derived from the same trial. While different outcomes were reported the review authors highlight incomplete and contradictory reporting between these publications that while not necessarily reflecting on the conduct of the trial does mean the reviewers could only consider the evidence to be of low quality. As the reviewers note these findings should be considered with caution and further high quality studies are needed.