Gingival Phenotype and Associated Factors in Orthodontically Treated Individuals and Untreated Controls: A...

Background/Objectives: Gingival phenotype is considered an important factor influencing periodontal tissue response during orthodontic treatment; however, the association between orthodontic treatment history and gingival phenotype remains unclear. This study aimed to compare gingival phenotype between orthodontically treated individuals and untreated controls and to evaluate the factors associated with gingival phenotype, including periodontal status and oral hygiene habits. Methods: This cross-sectional comparative study included 180 individuals aged 18-35 years, who were divided into two groups according to orthodontic treatment history (history of orthodontic treatment, n = 90; untreated controls, n = 90). Gingival phenotype was assessed using the transparency method at the mid-buccal aspect of the mandibular central incisor. Periodontal parameters, including Plaque Index (PI), Gingival Index (GI), probing depth (PD), and keratinized gingival width (KGW), were recorded. Oral hygiene habits and behavioral factors were also evaluated. Binary logistic regression analysis was performed to identify factors associated with gingival phenotype. Statistical significance was set at p < 0.05. Results: No significant association was found between orthodontic treatment and gingival phenotype (p > 0.05). Periodontal parameters were comparable between groups; however, orthodontically treated individuals demonstrated significantly better oral hygiene habits (p < 0.05). Logistic regression analysis revealed that male sex (OR = 6.54, p < 0.001) and increased KGW (OR = 1.668, p = 0.003) were independently associated with a thick gingival phenotype. Conclusions: The findings indicate that gingival phenotype appeared to be more strongly associated with intrinsic anatomical factors, particularly sex and KGW, rather than orthodontic treatment. It was concluded that individualized assessment of gingival phenotype and controlled orthodontic tooth movement may contribute to periodontal preservation.