Background: In Sweden, dental care for children and adolescents, including specialist orthodontic treatment, is publicly funded. This study aims to analyze the impact of sociodemographic factors on the distribution of publicly funded specialist orthodontic treatment in a mid-sized Swedish region. Methods: A registry-based cohort study was conducted in Region Östergötland, including individuals born between 2000 and 2003. Sociodemographic data were obtained from Statistics Sweden (SCB), while dental health information was sourced from The Swedish Quality Registry for Caries and Periodontal Disease (SKaPa). The primary outcome variable was initiation of specialist orthodontic treatment, extracted from dental records. Statistical analysis was performed using Stata v.18.1. Results: The cohort comprised 16 893 individuals, with 51.5% males and 48.5% females. Specialist orthodontic treatment was initiated for 25.7% of the population (n = 4 342), with most treatments involving fixed appliances. Several sociodemographic factors were significantly associated with the likelihood of receiving orthodontic treatment. Females had 1.74 times higher odds (95% CI: 1.63–1.87) of receiving treatment compared to males. Individuals born in Sweden had 1.42 times greater odds (95% CI: 1.18–1.72) of receiving treatment compared to those born abroad. Similarly, children with Swedish-born parents had 1.16 times increased odds (95% CI: 1.04–1.30) compared to children with foreign-born parents. Children of mothers with university/college education had an OR of 1.29 (95% CI: 1.12–1.48), while those whose fathers had a university/college education had an OR of 1.19 (95% CI: 1.05–1.34), compared to parents with primary/lower secondary education. Conclusions: Males, individuals born outside Sweden, those with foreign born parents, and whose parents had lower educational levels were less likely to receive orthodontic treatment within the publicly funded dental health services in Region Östergötland. These findings suggest that sociodemographic factors influenced the distribution of orthodontic care, though the role of treatment demand requires further investigation.