Abstract
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. The DMFT index was calculated to assess dental caries, and the gingival index (GI) was calculated for gingival health assessment. For oral hygiene assessment, the Oral Hygiene Index-Simplified (OHI-S) was calculated, and a questionnaire was used. RESULTS: Totally, 306 adolescents participated in this study. The frequency of IOTN grades was 88 (28.8%), 89 (26.1%) ,49 (16%), 60 (19.6%), and 29 (9.5%) for grades 1 to 5, respectively. The multinomial logistic regression showed that by an increase in OHI-S score, the odds of having IOTN grade 4 compared to grade 1 increased. Postgraduate parental level of education decreased the odds of having IOTN grade 4 compared to grade 1. Furthermore, there was an inverse correlation between oral hygiene practice and the odds of having IOTN grade 5 compared to grade 1. CONCLUSIONS: Malocclusion may hinder oral hygiene practice, and resultantly increase plaque accumulation. This risk may be amplified in children with lower SES, highlighting the need for preventive and educational oral health programs.