Mouth-breathing children (n = 439) aged 4 to 12 years, enrolled in and regularly attending the Mouth-breather Center (Centro do Respirador Bucal --- CRB) of the Universidade Federal de São Paulo/Escola Paulista de Medicina (UNIFESPEPM) from May of 2000 to May of 2011, were evaluated. Patients with genetic syndromes, orofacial malformations, or mental retardation were excluded.