Orthodontic treatment need according to the IOTN-DHC and AC indices: a cross-sectional study among adolescents aged 12–15 from different ethnic groups in Kosovo

BACKGROUND: Malocclusion affects oral function, self-esteem, and social integration, particularly in underserved ethnic communities. Despite its clinical and social impact, malocclusion remains insufficiently investigated in Kosovo and surrounding regions. This study assessed malocclusion among 12-15-year-old adolescents from different ethnic groups in Kosovo using the Dental Health Component (DHC) and Aesthetic Component (AC) of the Index of Orthodontic Treatment Need (IOTN), and examined potential interethnic differences. METHODS: A cross-sectional observational study was conducted among 454 adolescents aged 12-15 years, representing Albanian, Bosnian, Turkish, Serbian, and Roma/Ashkali/Egyptian (RAE) ethnic groups. Sociodemographic data (age, sex, ethnicity, residence, parental education) were collected using a structured questionnaire, while clinical assessments employed validated IOTN-DHC and IOTN-AC indices. RESULTS: The mean age of participants was 12.7 ± 0.8 years; 47.1% were male and 52.9% female. Ethnic distribution was Albanian (56.5%), RAE (14%), Turkish (12%), Bosnian (10%), and Serbian (8%). Significant interethnic differences were observed for residence, income level, and parental education (p ≤ 0.001). No significant differences were noted in IOTN-DHC grades 1-4 across ethnicities; however, Grade 5 showed a statistically significant difference across ethnic groups (χ² = 13.21, p = 0.010). The Kruskal-Wallis test showed significant variation in overall IOTN-DHC scores (χ² = 11.35, df = 4, p = 0.023), with Turkish adolescents exhibiting the highest treatment-need rank (254.1), followed by Bosnian (228.5), Serbian (210.4), Albanian (200.6), and RAE (174.7) adolescents. Pairwise Mann-Whitney U testing revealed significant differences between Albanian vs. Turkish (p = 0.001), Turkish vs. RAE (p = 0.048), and Turkish vs. Serbian (p = 0.041). After Bonferroni correction (p < 0.0056), only the Albanian vs. Turkish comparison remained significant (Z = - 3.175, p = 0.009), indicating a higher treatment need among Turkish adolescents. No significant interethnic differences were found in IOTN-AC scores (F = 1.54, p = 0.177). CONCLUSION: Significant ethnic disparities in orthodontic treatment needs were identified among adolescents in Kosovo, with Turkish adolescents showing the highest burden. These findings highlight the need for public health strategies focused on early detection, prevention, culturally sensitive education, and equitable orthodontic care to reduce oral health inequalities.