Body posture and pulmonary function in mouth and nose breathing children: cross-sectional study

Abstract Introduction: Mouth breathing can lead to changes in body posture and pulmonary function. However, the consequences are still inconclusive and a number of studies are controversial. Objective: Evaluate and correlate spirometric parameters and postural measures in mouth breathing children, and compare them to nose breathers. Methods: two groups of 6 to 12 year-old children were evaluated: mouth breathers (MB, n = 55) and nose breathers (NB, n = 45). Spirometry and body posture analysis using photogrammetry (SAPo 0.68® v) were carried out. The following spirometric measures were evaluated: peak expiratory flow (PEF), forced expiratory volume in 1 second (FEV1), forced vital capacity (FVC), FEV1/FVC ratio (%) and forced expiratory flow between 25% and 75% of FVC (FEF 25-75%). Biophotogrammetric measures analyzed were: horizontal alignment of acromions (HAA) and anterior superior iliac spine (HAASIS), Charpy angle, horizontal alignment of the head (HAH), cervical lordosis (CL), thoracic kyphosis (TK), lumbar lordosis (LL), cervical distance (CD) and lumbar distance (LD). Results: There were no intergroup differences in spirometric and postural variables. Positive and moderate correlations were found between CL and CD measures with PEF, FEV1, FVC and FEF 25-75%, while weak correlations were observed between lumbar lordosis and PEF, FEV1 and FVC. Conclusion: The breathing mode had no influence on postural and respiratory measures. However, greater forward head posture, with smaller cervical lordosis, was related to higher lung volumes and flows in both groups.