Considering the adverse effects of nonimpacted third molars (N-M3s) on the periodontal health of adjacent second molars (M2s), the removal of N-M3s may be beneficial to the periodontal health of their neighbors. This study aimed to investigate the clinical, immunological, and microbiological changes of the periodontal condition around M2s following removal of neighboring N-M3s across a 6-month period. Subjects with at least one quadrant containing an intact first molar (M1), M2, and N-M3 were screened and those who met the inclusion criteria and decided to receive N-M3 extraction were recruited in the following investigation. M2 periodontal condition was interrogated before M3 extraction (baseline) and at 3 and 6 months postoperatively. Improvements in clinical periodontal indexes of M2s in response to their adjacent N-M3 removal, along with changes in inflammatory biomarkers among gingival crevicular fluid (GCF) and the composition of subgingival plaque collected from the distal sites of the M2s of the targeted quadrant were parallelly analyzed. Complete data of 26 tooth extraction patients across the follow-up period were successfully obtained and subsequently applied for statistical analysis. Compared to the baseline, the periodontal condition of M2s was significantly changed 6 months after N-M3 removal; specifically, the probing depth of M2s significantly reduced (P < 0.001), the matrix metalloproteinase (MMP)-8 concentration involved in GCF significantly decreased (P = 0.025), and the abundance of the pathogenic genera unidentified Prevotellaceae and Streptococcus significantly decreased (P < 0.001 and P = 0.009, respectively). We concluded that N-M3 removal was associated with superior clinical indexes, decreased GCF inflammatory biomarkers, and reduced pathogenic microbiome distribution within the subgingival plaque. Although the retention or removal of N-M3s continues to be controversial, our findings provide additional evidence that medical decisions should be made as early as possible or at least before the neighboring teeth are irretrievably damaged.

考虑到非阻生第三磨牙（N-M3）对邻近第二磨牙（M2）牙周健康的不利影响，去除N-M3可能对其邻牙的牙周健康有益。本研究旨在调查去除邻近的 N-M3 后 6 个月内 M2 周围牙周状况的临床、免疫学和微生物学变化。筛选至少一个象限包含完整第一磨牙（M1）、M2 和 N-M3 的受试者，并招募符合纳入标准并决定接受 N-M3 拔除的受试者参加以下调查。在 M3 拔牙前（基线）以及术后 3 个月和 6 个月检查 M2 牙周状况。 M2s 的临床牙周指数因邻近的 N-M3 去除而改善，同时龈沟液 (GCF) 中炎症生物标志物的变化以及从目标象限 M2s 远端部位收集的龈下菌斑成分也发生变化。分析了。成功获得26名拔牙患者随访期间的完整数据并随后进行统计分析。与基线相比，N-M3去除后6个月，M2s的牙周状况发生显着变化；具体而言，M2s的探测深度显着降低（ P <<0.001），GCF参与的基质金属蛋白酶（MMP）-8浓度显着降低（ P =0.025），未鉴定的致病菌属普氏菌属和链球菌的丰度显着降低（ P < 0.001 和P = 0.009，分别）。 我们得出的结论是，去除 N-M3 与优异的临床指标、减少 GCF 炎症生物标志物以及减少龈下菌斑内病原微生物组的分布有关。尽管保留或去除 N-M3 仍然存在争议，但我们的研究结果提供了额外的证据，表明应尽早或至少在邻近牙齿受到不可挽回的损坏之前做出医疗决定。