下顎智歯埋伏歯抜歯に関する多機関共同後ろ向き観察研究：高齢群と若年群との比較

Tooth extraction in young patients to prevent future complications due to impacted lower third molar （M3） remains controversial. The aim of the present study was to assess the efficacy of prophylactic extraction of the impacted lower M3. This multicenter retrospective study involved a chart review of the clinical records of patients treated with extraction of impacted lower M3 in each institution between April 2018 and March 2021. Data were collected, and the pre-, intra- and post-operative complications were analyzed between 273 elderly patients and 1,734 younger patients. The rates of occurrence of postoperative hemorrhage, nerve sensory change, dry socket and postoperative infection were significantly higher in elderly patients than in younger patients （P＜0.001）. Epithelial, nerve sensory change, dry socket and postoperative infection were significant independent risk factors （P＜0.001）. Pre-operative cellulitis and cyst caused by impacted lower M3 were significantly more common in elderly patients, and cyst caused by impacted lower M3 was an independent risk factor for postoperative infection （P＝0.021）. In conclusion, prophylactic extraction of the impacted lower M3 is effective for avoiding some pre- and post-operative complications. However, the current evidence is inadequate to recommend it.