RESUMO
OBJECTIVES: The effect of combined orthodontic-orthognathic treatment was estimated, specifically the impact of pre-surgical orthodontic treatment, on oral health-related quality of life (OHRQoL). MATERIALS AND METHODS: The research question was formulated using the PICO method. The search was carried out in MEDLINE via PubMed, CINAHL, psychINFO, Embase, and Cochrane (until February 3, 2020). Inclusion criteria were patients aged ≥ 17 years who underwent combined orthodontic-surgical treatment, quality of life assessment, and study design of randomized controlled trial, controlled clinical trial, prospective cohort study, observational study, intervention study, or cross-sectional study. The ROBINS-1 tool was used to assess the risk of bias within studies. A random effects meta-analysis was conducted when appropriate. The quality of evidence was assessed using the GRADE approach. RESULTS: Six studies were analyzed. The OHIP-14 and/or OQLQ-22 questionnaires were used to measure the OHRQoL. All six studies had a serious risk of bias. Two studies (87 participants) were included in a meta-analysis showing improvement of OHRQoL when comparing before and after treatment were compared (mean 14.85 scale points, 95% confidence interval 10.36;19.35). CONCLUSIONS: Studies indicate a decrease in OHRQoL during the pre-surgical orthodontic treatment phase but improvement after orthodontic-orthognathic treatment. Data substantiating these results are limited, and the quality of evidence is low. Further research is needed to assess the impact of pre-surgical orthodontic treatment on the OHRQoL in an orthognathic trajectory. CLINICAL RELEVANCE: Patients should be well informed about the effect facial/esthetic changes may have on their OHRQoL during sequential phases of orthodontic-orthognathic treatment.