# Prevalence of Malocclusion and Orthodontic Treatment Need in 9- to 12-Year-Old Schoolchildren in Ulaanbaatar, Mongolia

## TL;DR

This study assesses the need for orthodontic treatment in 9- to 12-year-old children in Ulaanbaatar, Mongolia, finding that about one-third require treatment.

## Contribution

The study provides updated data on malocclusion prevalence and treatment needs in Mongolian children using the IOTN index.

## Key findings

- 84.5% of children had malocclusion, with Angle Class I being the most common.
- Approximately 37.4% of children had moderate or definite need for orthodontic treatment.
- Overjet, crowding, and overbite were the most common malocclusions associated with treatment need.

## Abstract

Background

The prevalence of malocclusion in Mongolia is increasing every year. Estimating the need for orthodontic treatment in the population is crucial for planning orthodontic care services and monitoring oral health programs. Therefore, the present study aimed to assess the need for orthodontic treatment among schoolchildren in Ulaanbaatar, Mongolia, using the Index of Orthodontic Treatment Need (IOTN).

Methods

A total of 656 schoolchildren aged 9-12 years were enrolled from 8 schools located in urban and suburban areas of 6 districts of Ulaanbaatar city. All the children were assessed according to the two components of the IOTN, the Dental Health Component (DHC) and the aesthetic component (AC). Statistical analyses were carried out using IBM SPSS Statistics for Windows, Version 28 (Released 2021; IBM Corp., Armonk, New York, United States).

Results

The prevalence of malocclusion was 561 (84.5%), consisting of 452 (68%) Angle Class I, 178 (26.8%) Angle Class II, and 34 (5.2%) Angle Class III malocclusion. For the DHC, the moderate need for treatment was 194 (29.3%) and the definite need was 53 (8.1%). For the AC, the moderate need was 148 (22.3%) and the definite need was 45 (6.9%). The association between the DHC and the AC was found to be statistically significant (p<0.001). The most common malocclusions were an increased overjet (maxillary protrusion), a contact point displacement (crowding), and an increased overbite (deep bite). The AC, Angle’s molar relationship, an increased overjet, a contact point displacement, and an increased overbite were factors associated with the need for orthodontic treatment.

Conclusion

Approximately one-third of schoolchildren in Ulaanbaatar, Mongolia, require orthodontic treatment. This finding helps dental practitioners to better understand oral health problems, leading to an improvement in the overall quality of life of children.