Abstract This article aims to assess whether alterations of oral functions (AOF) are associated with malocclusion (MO)’s type and severity. Cross-sectional study of a representative sample of 332 adolescents aged 12 years in São Luís-MA, Northeastern Brazil. MO criteria included Angle’s classification, Dental Aesthetic Index, and other morphological problems. The AOF were evaluated by breathing, phonation, chew...