Gingival phenotype prevalence of lower incisors and associated risk indicators in the French dental student population: a cross-sectional study.

Abstract

Objectives: To investigate the prevalence of the gingival phenotype in the mandibular incisor area and the associated risk indicators.

Materials and methods: This cross-sectional study involved clinical examination to record main periodontal characteristics (gingival phenotypes) at the tooth level. Then, a phenotype at the subject level was defined as fragile (at least one thin phenotype on one of the four incisors) versus resistant (no thin phenotype on the four incisors). Furthermore, orthodontic parameters were assessed based on photographic examination. Two blinded periodontists and two blinded orthodontists were involved in the data collection. Univariate and multivariate logistic regression models were implemented.

Results: A total of 119 students were included, encompassing 476 incisors. The prevalence of gingival phenotypes at the tooth level was as follows: thin/high (63.9%), thick/high (36.3%), thin/reduced (5.9%), and thick/reduced (0.2%). At the subject level, the fragile phenotype predominated (81.5%) and showed a significant correlation with the visibility of roots prominence (OR = 4.09, 95% CI: 1.47-11.41, p = 0.007).

Conclusions: Considering the conditions of this study, in the mandibular incisor area, the thin/high gingival phenotype exhibited the highest prevalence at the tooth level. At the subject level, the presence of visible roots prominence was identified as the only significant risk indicator associated with the fragile phenotype.

Clinical relevance: General practitioners, periodontists and orthodontists should consider the mandibular incisor sector as a vulnerable area. Categorizing the overall gingival phénotype into 4 types improves the diagnostic approach and allows better identification of high-risk phenotypes, especially in cases requiring multidisciplinary management.

Clinicaltrial:

Gov record: Number NCT05813444.