Impact of vertical facial patterns and oral habits on microbial colonization in children and adolescents: a cross-sectional study

The oral commissures represent a unique anatomical interface where intra- and extra-oral environments converge. This study aimed to investigate the association between vertical facial patterns and microbial colonization at the oral commissures in children and adolescents. A total of 150 healthy participants (mean age 13.4 ± 2.7 years; range: 8–18 years) were equally divided into low-, norm-, and high-angle groups according to their cephalometric GoGn/SN values. Swab samples from both oral commissures were cultured for Candida species and Gram-positive bacteria. Commissural wetness, intraoral pH, and oral habits were recorded. Group differences were analysed using chi-square and one-way ANOVA tests (α = 0.05). Vertical facial morphology showed a significant association with bacterial colonization findings (p = 0.001). Gram-positive bacilli were absent in low-angle but frequent in norm- and high-angle individuals. Candida carriage (12.0%) showed no significant association with facial pattern (p = 0.103). Mouth breathing was significantly more prevalent in high-angle participants (p = 0.038), while lip-licking habits showed no intergroup difference. Increased vertical facial dimension was associated with bacterial, but not fungal, findings at the oral commissures. Craniofacial morphology may therefore be related to local microbial findings and could be considered a potential modifying factor in paediatric patients presenting with recurrent angular lesions.