[Effect of residual dental follicle after removal of impacted mandibular third molar on the periodontal health of adjacent second molar].

Abstract

Objective: To investigate whether residual dental follicles in the alveolar socket after extraction of impacted mandibular third molars affect the periodontal health of adjacent mandibular second molars, in order to provide clinical reference for the management of residual dental follicles after third molar extraction. Methods: A total of 82 patients who underwent bilateral impacted mandibular third molar extraction at the Department of Oral Surgery, School and Hospital of Stomatology Wuhan University, from November 1, 2020, to November 30, 2022, were included in the study. Using a self-controlled method, each patient's bilateral mandibular third molars were randomly divided into two groups: Group A underwent third molar extraction with thorough removal of residual dental follicle tissue, while Group B underwent third molar extraction without any treatment of the remaining dental follicle tissue. Operation time and adverse reactions were recorded. Clinical and radiographic examinations were performed at 6-month follow-up to evaluate the periodontal parameters and alveolar bone height of the bilateral mandibular second molars, and differences between the two groups were compared. Results: All patients had successful bilateral mandibular third molar extractions, and no serious complications occurred intraoperatively or postoperatively. There were no statistically significant differences in surgical time, postoperative pain, or facial swelling between the two groups (P>0.05). At the 6-month follow-up, the probing depth on the distal aspect of the mandibular second molars in Group A [2.67 (2.00, 3.67) mm] was significantly less than that in Group B [4.00 (3.00, 5.00) mm] (Z=-6.55, P<0.001). The clinical attachment loss on the distal aspect of the mandibular second molars in Group A [1.00 (0.00, 3.00) mm] was less than that in Group B [3.00 (2.00, 5.00) mm] (Z=-5.99, P<0.001). The distance from the alveolar crest to the cementoenamel junction on the distal aspect of the mandibular second molars in Group A [(1.86±1.34) mm] was less than that in Group B [(3.04±1.89) mm] (t=6.87,P<0.001). In patients aged≥20 years, the probability of recovery of alveolar bone height to normal level on the distal aspect of the mandibular second molars in Group A [42.3% (11/26)] was significantly higher than that in Group B [0 (0/26)] (P<0.01), while there was no statistically significant difference between Group A [63.3% (19/30)] and Group B [46.7% (14/20)] in patients aged<20 years (P>0.05). Conclusions: Residual dental follicles in the alveolar socket after extraction of impacted mandibular third molars adversely affect the periodontal health of adjacent teeth. Thorough removal of residual dental follicles during impacted mandibular third molar extraction is beneficial for the postoperative recovery of alveolar bone height of the distal aspect of the mandibular second molars, especially in patients aged≥20 years.