[Preliminary study on factors associated with the gingival papillae deficiency between maxillary anterior teeth in periodontitis patients with alveolar ridge resorption].

Objective: To evaluate the factors associated with the gingival papilla deficiencies of different degrees between maxillary anterior teeth showing alveolar ridge absorption. Methods: A total of 64 gingival papillae between maxillary anterior teeth of 14 patients with periodontitis, who received periodontal treatment and regular review in the Department of Periodontology, Peking University School and Hospital of Stomatology from June 2019 to December 2019, were observed in the present study. Indices were measured by using standardized clinical photographs and cone-beam CT images. The correlations between the gingival papilla deficiencies of different degrees and the distance from contact point to bone crest (CP-BC), the distance from proximal cemento-enamel junction to bone crest (pCEJ-BC), interproximal distance between roots (RD), the width of bone crest (BCW) and the height of gingival papilla (PH) were evaluated. Statistical analyses such as t-test, ANOVA, Pearson correlation coefficient and so on were conducted. Results: The rate of maxillary anterior gingival papilla completely filled the adjacent spaces between anterior teeth was 28% (18/64) and the rate of gingival papilla with deficiencies was 72% (46/64). The mild, moderate and severe deficiencies were 36% (23/64), 27% (17/64) and 9% (6/64) respectively. When CP-BC≥7.0 mm or pCEJ-BC≥4.5 mm, only moderate or severe deficiencies appeared. However, when CP-BC<5.0 mm or pCEJ-BC<1.5 mm, only completely filled adjacent tooth space or mild deficiency appeared. There was a strong positive correlation between CP-BC and pCEJ-BC. The Pearson correlation coefficient was 0.812 (P<0.01), and the linear fitting coefficient was 0.93 (R2=0.659) (64 gingival papillae). There was no significant difference of RD for gingival papilla deficiencies of different degrees between maxillary anterior teeth (P>0.05). BCW at the crest level increased slightly with the increase of the degree of gingival papilla deficiency, and the difference was statistically significant between completely filled adjacent tooth space and moderate or severe deficiency (P<0.05). However, PH at the crest level decreased slightly with the increase of the degree of gingival papilla deficiency, and the difference was statistically significant between completely filled adjacent tooth space and moderate or severe deficiency (P<0.05). Conclusions: When the alveolar ridge is absorbed, the rate of deficiency is significantly higher than the completely filled adjacent tooth space. The gingival papilla deficiencies of different degrees between maxillary anterior teeth are mainly associated with the absorption of bone crest.