Surgically assisted rapid maxillary expansion with bone-borne versus tooth-borne distraction appliances-a systematic review

The objective was to test the hypothesis of no difference in skeletal and dental arch expansion and relapse after surgically assisted rapid maxillary expansion with a bone-borne compared with a tooth-borne appliance. The PubMed, Embase (Ovid), Cochrane Library, and Google Scholar databases were searched in combination with a hand-search of relevant journals up until December 2017. No language restriction was applied. Two short-term randomized controlled trials with a low risk of bias fulfilled the inclusion criteria. No meta-analysis could be performed due to considerable heterogeneity. There were no statistically significant differences in the skeletal and dental arch expansion and relapse. Dental arch expansion was significantly greater than skeletal expansion with both treatment modalities. However, dissimilar evaluation methods, different outcome measures, unknown vertical level of force application with the bone-borne devices, and various methodological confounding factors posed serious restrictions to reviewing the literature in a quantitative systematic manner. Hence, conclusions drawn from the results of this systematic review should be interpreted with caution. Further well-designed long-term randomized clinical trials including a standardized protocol and three-dimensional analysis of the level of force application and morphological outcome are therefore needed before one treatment modality can be considered superior to the other.