Dentist, Private Practice, Soest, Germany; and Research Assistant, Department of Periodontology, Center for Dentistry and Oral Medicine (Carolinum), Johann Wolfgang Goethe-University Frankfurt/Main, Frankfurt/Main, Germany.
Dental hygienist, Private Practice, Soest, Germany.
J Oral Maxillofac Surg. 2021 Mar;79(3):520-531. doi: 10.1016/j.joms.2020.11.013. Epub 2020 Nov 23.
The removal of third molars (M3) is one of the most common oral-maxillofacial surgical procedures affecting periodontal tissues of neighboring second molars (M2). The aim of this study was to evaluate the periodontal status of lower M2 following the removal of unerupted lower M3 up to 5 years after removal.
Primary predictor variable in this prospective cohort-study was time [baseline (BL; preoperatively), 6 and 60 months postoperatively]. The primary outcome variable was probing pocket depth (PPD). Clinical attachment level (CAL) was defined as a secondary outcome variable. Plaque index (PlI) and gingival index (GI) were assessed descriptively. All variables were compared using nonparametric tests. M3 were classified as either completely bony or partially bony unerupted. Risk factors (removed M3, type of impaction, mean BL PPD≥4 mm, gender, age) were analyzed (repeated measures ANCOVA). The significance level was set at 0.05.
From originally 91 subjects enrolled in this study, 39 subjects (22 females; mean age: 21.6 ± 2.5 years) contributing 39 M3 completed the study after 5 years. Average BL PPD significantly decreased at 6 (-0.50 ± 0.61 mm, P = .001), 60 months (-0.81 ± 0.56, P < .0001), as well as between 6 and 60 months (-0.31 ± 0.51 mm, P = .030). Corresponding CAL values decreased accordingly (BL-6 months: -0.37 ± 0.59 mm, P = .004; BL-60 months: -0.67 ± 0.55 mm, P < .0001; 6 to 60 months: -0.34 ± 0.48 mm, P = .004). The was confirmed as risk factor for PPD (P = .026) and CAL (P = .042) changes.
Average PPD and CAL of mandibular M2 in young subjects improved 5 years after early removal of unerupted M3 in favor of an initial partially bony unerupted type of impaction.
拔除第三磨牙（M3）是最常见的口腔颌面外科手术之一，会影响邻近第二磨牙（M2）的牙周组织。本研究旨在评估 M3 未萌出时 M2 的牙周状况，直至 M3 拔除后 5 年。
本前瞻性队列研究的主要预测变量为时间[基线（BL；术前）、术后 6 个月和 60 个月]。主要结局变量为探诊袋深度（PPD）。临床附着丧失（CAL）定义为次要结局变量。菌斑指数（PlI）和牙龈指数（GI）进行描述性评估。所有变量均采用非参数检验进行比较。M3 分为完全骨埋伏或部分骨埋伏未萌出。分析风险因素（被拔除的 M3、阻生类型、平均 BL PPD≥4mm、性别、年龄）（重复测量方差分析）。显著性水平设定为 0.05。
最初纳入本研究的 91 名受试者中，39 名受试者（22 名女性；平均年龄 21.6±2.5 岁）完成了 5 年研究，共贡献了 39 颗 M3。BL PPD 平均在 6 个月时（-0.50±0.61mm，P=.001）、60 个月时（-0.81±0.56mm，P<.0001）以及 6 至 60 个月时（-0.31±0.51mm，P=.030）显著降低。相应的 CAL 值也相应下降（BL-6 个月：-0.37±0.59mm，P=.004；BL-60 个月：-0.67±0.55mm，P<.0001；6 至 60 个月：-0.34±0.48mm，P=.004）。M3 被证实为 PPD（P=.026）和 CAL（P=.042）变化的风险因素。
年轻受试者在 M3 早期未萌出时，M2 的平均 PPD 和 CAL 在 5 年后得到改善，有利于初始部分骨埋伏型阻生。
