LAUSR

Purpose Adenotonsillectomy is the first-line treatment for pediatric obstructive sleep apnea (OSA). However, although completely resolved OSA after adenotonsillectomy, some children still showed persistence of mouth breathing. Therefore, we attempted to identify risk factors for residual mouth breathing in children with OSA after successful adenotonsillectomy. Materials and methods This study retrospectively enrolled children who underwent adenotonsillectomy as a treatment of OSA. Additionally, children who showed apnea–hypopnea index ≥ 1 on 1-year postoperative polysomnography or adenoid regrowth on one-year postoperative lateral cephalogram were excluded. The presence of allergic rhinitis, septal deviation, dentofacial abnormalities, the size of tonsil and adenoid was also evaluated in all enrolled children. Dentofacial abnormalities were defied as a high palatal arch, macroglossia, retrognathia, micrognathia, and overcrowding of teeth which assessed by dentists. Results A total of 62 children were enrolled (no residual mouth-breathing group, n  = 18 and residual mouth-breathing group, n  = 44) in this study. There were no significant differences in demographic factors, physical examination, and sleep parameters, except age and preoperative adenoid size. On the multiple logistic regression analysis, we found that older age, large adenoid size, and presence of dentofacial abnormalities significantly correlated with residual mouth breathing (adjusted coefficient estimates = 0.3890, 2.3611, and 2.8615, respectively) after successful adenotonsillectomy. Conclusions Older age, large adenoid size, and presence of dentofacial abnormalities in children with OSA may be the risk factors for residual mouth breathing after successfully resolved OSA.