Abstract
BACKGROUND/OBJECTIVES: Anterior open bite is a multifact orial malocclusion influenced by genetic and environmental factors. Variants in the Collagen type I, alpha 1 (COL1A1) gene, particularly rs1800012, have been implicated in bone quality, but their role in craniofacial anomalies remains unclear. METHODS: A case-control study was conducted with 60 participants (30 anterior open bite cases; 30 matched controls). DNA was extracted from buccal swabs, and rs1800012 genotyping was performed using TaqMan assays. Genotype and allele distributions were compared with chi-square and Fisher's exact tests; Hardy-Weinberg equilibrium was assessed in controls. RESULTS: Genotype (GG/GT/TT: 53.3/40.0/6.7% vs. 60.0/33.3/6.7%) and allele (T allele: 26.7% vs. 23.3%) frequencies did not differ significantly between cases and controls. No association was detected under additive, dominant, or recessive models (all p > 0.05). Wide confidence intervals indicated limited precision of effect estimates. CONCLUSIONS: This study provides no evidence of association between COL1A1 rs1800012 and anterior open bite in this Turkish cohort. The relatively small sample size, the rarity of the TT genotype, and the multifactorial nature of craniofacial development represent important limitations. Larger, multi-gene, and functionally integrated studies are required to clarify the genetic architecture of open bite malocclusion.