Comparison of gingival and periodontal phenotype classification methods and phenotype-related clinical parameters: cross-sectional observational study

Abstract

Background: The aim of this study was to assess gingival and periodontal-phenotype by using Standard-Periodontal-Probing (SPP), Colored-Periodontal-Probing (CPP), and Cone-Beam-Computed-Tomography (CBCT) in comparison to gold standard transgingival-probing. Methods: Gingival-thickness of the maxillary anterior incisors and canines of 30 healthy individuals (6 teeth of each individual) was evaluated by transgingival-probing, SPP, CPP, and CBCT methods. The relationship between thin and thick phenotype and phenotypic parameters such as age, gender, Keratinized-Tissue-Width (KTW), and Buccal-Bone-Thickness (BBT) was tested with the Chi-square test, and the differences between the measurements were tested with the Mann-Whitney U test. Gingival-thickness, BBT, and related phenotypic parameters were measured from three buccal points (marginal-middle-apical) of each tooth, and Spearman-Rho Correlation Analysis was performed. Pearson chi-square and McNemar tests were used to assess the distribution of categorical data. Sensitivity, specificity and accuracy levels and kappa statistics were calculated for each method. Intra/interobserver agreement was assessed using the intraclass correlation coefficient. The significance level was set at p < 0.05. Results: There was no statistically significant difference for gingival-phenotype according to age and gender (p > 0.05). Higher KTW values were measured in areas with thick gingival-phenotype (p:0.008). The highest agreement in terms of detecting gingival-phenotype was found between transgingival-probing and CBCT (p < 0.01). All methods were found to be more accurate in the determination of thin phenotype (p < 0.01). Marginal gingival-thickness measurements were higher than those of middle and apical measurements (p < 0.01), and middle BBT measurements were higher than those of apical measurements (p < 0.01). Gingival-thickness measured by transgingival-probing and CBCT showed a significant correlation (p < 0.01). KTW was significantly correlated with BBT and marginal gingival-thickness (p < 0.01). Conclusions: Thin or thick phenotype is associated with different apical-coronal points and KTW. The CBCT method was found to be helpful in determining gingival and periodontal-phenotype. Clinical relevance: Available CBCT images can be used to take precautions and assess prognosis before implant placement and orthodontic treatment. Clinical trial number: Not applicable.