Correlation between Dental Caries, Gingivitis, and Malocclusion in School-aged Children: A Cross-sectional Study

Abstract

Oral diseases are important public health issues affecting school-aged children, yet comprehensive studies on interrelationships among dental caries, gingivitis, and malocclusion remain lacking. This cross-sectional study assessed prevalence, correlations, and risk factors of these three diseases in 502 children aged 6-12 years from three elementary schools in Guangzhou, China (October 2024-January 2025). Demographic characteristics, oral hygiene habits, and dietary behaviors were collected through questionnaires. Clinical assessments used DMFT/dmft index, Gingival Index, ICDAS, and Angle classification. Dental caries prevalence was 45.4%, exhibiting an inverted U-shaped age pattern: 52.7% (6-8 years), 39.7% (9-10 years), and 44.4% (11-12 years), reflecting primary-to-permanent dentition transition. Gingivitis prevalence was 48.6% and malocclusion 68.3%, with 23.7% experiencing all three conditions simultaneously. Correlation analysis revealed moderate positive correlation between caries and gingivitis (r=0.342), and weak correlations between caries-malocclusion (r=0.268) and gingivitis-malocclusion (r=0.231), all statistically significant. Multivariate analysis identified major risk factors: daily sweet consumption (OR=2.14), inadequate brushing (OR=1.87), no dental floss use (OR=2.23), and thumb-sucking (OR=2.87). Age demonstrated significant quadratic relationship with caries (P=0.031), confirming the non-linear pattern. These oral diseases show high prevalence and significant interrelationships, requiring comprehensive prevention strategies and age-specific interventions targeting primary tooth preservation (6-8 years), timely sealants (9-10 years), and comprehensive prevention (11-12 years).