Geographical Disparities in Orthodontic Treatment Demand: 15-Year-Old Vietnamese Population Analyzed by Dentist-Population Ratio.

Background: While orthodontists determine the need for treatment, the demand for treatment is a patient's own decision, based on a questionnaire that addresses their self-perception of their dentition and facial aesthetics. The demand for professional treatment depends on a wide range of factors, such as socioeconomic status, culture, age, and self-perceived appearance, which is sometimes poorly correlated with the normative need for treatment. This study investigated the malocclusion prevalence and orthodontic treatment demand among 15-year-olds in Ho Chi Minh City, considering geographical disparities based on dentist-to-population ratios in three distinct areas: the urban center (6 dentists/10,000 population), para-center (1.6 dentists/10,000 population), and peri-urban areas (0.9 dentists/10,000 population). Material and Methods: Utilizing multi-stage cluster sampling, 673 children were selected, ensuring representation from each area. Participants completed questionnaires on treatment demand and underwent orthodontic examinations using the Index of Orthodontic Treatment Need (IOTN). Analysis involved conventional statistics and decision tree models. Results: Results revealed a prevalence of 37% and 46.95% for severe malocclusion, with a noTable demand for treatment (51%), particularly prominent in the urban center area. Decision tree analysis achieved 0.67 accuracy in predicting treatment demand, identifying children from urban centers with DHC-IOTN scores ≥4 as most likely to demand treatment. Conclusions: Our study reveals geographic disparities in orthodontic demand among 15-year-olds in Ho Chi Minh City, driven by differences in dentist-population ratios. A decision tree model could be effective for clinicians and strategists in determining the most appropriate way to meet the demand for early orthodontic treatment in adolescents across different neighborhoods. Key words:AC-IOTN, DHC-IOTN, malocclusion, orthodontic treatment need and demand, decision tree.