Bae J, et al. - Despite complete resolution of obstructive sleep apnea (OSA) after adenotonsillectomy, persistence of mouth breathing is observed in some children. Hence, risk factors for residual mouth breathing in these children have been investigated in this study. Researchers retrospectively enrolled 62 children who underwent adenotonsillectomy as a treatment of OSA; among these children, 18 had no residual mouth-breathing and 44 showed residual mouth-breathing. Observations revealed following as risk factors for residual mouth breathing after successfully resolved OSA: Older age, large adenoid size, and presence of dentofacial abnormalities in children with OSA.