Effects of laser therapy on patients who underwent rapid maxillary expansion; a systematic review.

Rapid maxillary expansion (RME) is one of the common treatments of transverse maxillary deficiency, and low-level laser therapy (LLLT) is one of the recommended solutions to enhance biological wound or bone healing. This review article aims to answer the following question: "What are the effects of LLLT, on patients who underwent surgical or non-surgical RME, in improving clinical success, wound healing, and bone regeneration?" A search in PubMed, Scopus, Web of Science, and ProQuest databases was performed, with a focus on the appropriate key words. Related articles, up to May 2017, were screened, and the full text of the randomized controlled trials (RCT) were comprehensively read and subjected to quality assessments. A total of 1804 articles were included after the initial search. Four RCTs were eligible in randomization and methodology. The applied wavelength varied from 660 to 830 nm with an output range of 40-100 mW. Also, the highest exposed energy was 420 J/cm2 and the lowest was 100 J/cm2. The exposure time differed from 20 to 84 s in each defined point in the palate. Based on the RCTs available, LLLT is better to be used at initial phase of RME, because it has some benefits in increasing the rate of bone remodeling.