Background: This study aimed to assess the effect of malocclusion severity according to the Index of Treatment Need (IOTN) on oral health (dental caries and gingivitis), and its correlation with socioeconomic status (SES) in Iranian adolescents.
Methods: This descriptive cross-sectional study was conducted on adolescents between 10 and 16 years in Tehran city, who underwent clinical dental examination. The Dental Health Component (DHC) of the IOTN was used to assess the severity of malocclusion.