Influence of clinical and demographic factors on the oral health-related quality of life of patients with cleft lip and palate undergoing orthodontic treatment: a systematic review and meta-analysis

Objective The purpose of this study was to evaluate the influence of orthodontic treatment on the oral health-related quality of life (OHRQoL) of patients with cleft lip and palate. Search methods Electronic searches were conducted in Pubmed, Scopus, Web of Science, Cochrane Library, VHL, and OpenGrey databases, completed in January 2021. Selection criteria Cross-sectional and longitudinal observational studies that presented an assessment of OHRQoL in cleft patients undergoing orthodontic treatment were included, according to PRISMA guidelines. Contacts via email were made with authors, to clarify inaccuracies or request additional data. Data collection and analysis The entire process was accomplished by two authors, in case of disagreement, a third author mediated the discussion until there was a consensus. Risk assessment was performed by the Fowkes and Fulton qualifier, and the quality of evidence, assessed by the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) tool. A meta-analysis was performed considering the domains combined into three large groups (physical, psychological, and social). The questionnaires were standardized as to the scores and their direction. Results A total of 3822 studies were retrieved. After excluding duplicates, the titles and abstracts of the remaining articles were analysed. Twenty-eight articles were read in full; 13 met the eligibility criteria; 12 articles showed sufficient methodological quality and 7 were included in the quantitative assessment. The included studies were published between 2011 and 2019. The samples comprised 19 to 183 patients of both sexes. GRADE showed low evidence when compared to the control group, sexes, age, and types of cleft and very low evidence among longitudinal articles. Conclusions The OHRQoL is lower in orthodontic patients with cleft than in those without. The OHRQoL of patients with cleft undergoing orthodontic treatment is not influenced by gender or age group, considering children and adolescents, but it is influenced by the type of cleft. The OHRQoL of patients with CLP does not undergo significant changes during orthodontic treatment. Limitations The variety of instruments for measuring OHRQoL rendered meta-analysis difficult. Registration PROSPERO database number CRD42017054764.