RESUMEN
BACKGROUND: Mouth breathing syndrome can cause sleep disturbances that compromise the performance of children in school. It might also cause postural abnormalities involving the head and cervical spine; however, the association between postural abnormalities and mouth breathing in children is unclear. OBJECTIVE: To assess the methodological quality of studies and determine if there is an association between mouth breathing and postural disorders in children. METHODS: Databases comprised MEDLINE, CINAHL, PEDro, LILACS, EMBASE and Cochrane Central Registrar of Controlled Trials. Searches were until March 2016 and included studies that evaluated postural disorders in children diagnosed with mouth breathing. The Downs and Black checklist was used to evaluate the quality of the evidences. RESULTS: Ten studies were included totaling 417 children from 5 to 14 years. Two studies used the New York State Postural Rating Scale, seven used photography and one used motion capture to measure posture. The methods used to analyze the data included the Postural Analysis Software (SAPO), Fisiometer, ALCimagem and routines in MATLAB program. Quality assessment resulted in low scores (<14) for all the studies. The main areas of weakness were a clear description of the participants, of the methods used to access posture, of the principal confounders and lack of power analysis. External and internal validity were also threatened by the lack of a representative sample and blinding of the participants and assessors, respectively. CONCLUSIONS: The review provides low evidence that mouth-breathing pattern in children between the ages 5-14 years is associated with postural deviations.