下颌阻生智齿拔除同期植骨改善牙根外吸收邻牙的预后分析

Effect of extraction of impacted mandibular wisdom teeth with concurrent socket grafting on external root resorption of adjacent teeth

摘要:

目的 分析下颌阻生智齿导致第二磨牙（M2）牙根外吸收但无临床症状的患者采用智齿拔除同期植骨，术后1年随访评价M2的牙髓-牙周状态，为制订临床治疗策略提供参考。方法 选取2017年5月—2022年8月在北京大学口腔医院口腔颌面外科就诊要求拔除下颌阻生智齿的15例患者（15颗），智齿拔除同期植入骨粉，术后随访1年以上，对M2的牙髓-牙周愈合情况进行临床和锥形束CT评价。结果 15例患者术后随访（30.4±10.1）个月，所有患者均无牙髓症状，牙齿无松动，3例（20%）患者M2电活力读数> 40，14例（93.33%）患者M2冷测正常，1例（6.67%）患者M2冷测迟钝。M2远中牙龈指数（0.5±0.8），探诊深度（4.5±1.9）mm（3～9 mm），其中3例（20%）M2远中探诊深度≥ 7 mm，探诊出血4例（24.7%）。锥形束CT检查：M2远中骨缺损高度（0.2±1.7）mm（-1.9～5.1 mm），1例（6.67%）骨缺损高度> 4 mm。7例（46.7%）患者牙根-植骨材料界面表现清晰连续的牙周膜间隙样结构；5例（33.3%）界限模糊，3例（20%）不规则增宽。此外，2例（13.33%）牙根表面外吸收处有牙骨质或牙槽骨样硬组织沉积修复，恢复锥状牙根外形。结论 对下颌完全埋伏阻生智齿致M2牙根外吸收患者，智齿拔除同期植骨后M2牙髓-牙周可获得较好的预后效果，对于M2牙根再生现象，需要进一步组织学研究证实。

Abstract:

Objective To observe the pulpal and periodontal status of mandibular second molar (M2) one year after extraction of impacted mandibular wisdom teeth (M3) that causes external root resorption of M2 and concurrent socket grafting in asymptomatic patients, so as to provide a reference for establishing therapeutic strategies.Methods Fifty patients (15 teeth) with asymptomatic M2 external root resorption caused by impacted M3 in the Department of Oral and Maxillofacial Surgery of Peking University Hospital of Stomatology from May 2017 to August 2022 were included. All of them underwent extraction of M3 and concurrent socket grafting. The pulpal and periodontal healing of M2 was evaluated clinically and radiographically after more than 1 year of follow-up.Results The fifty patients were followed up for (30.4 ± 10.1) months after the operation. All of them had no symptoms of pulpal diseases or loose teeth. Three cases (20%) of M2 electrical vitality were greater than 40, 14 cases (93.33%) of M2 showed normal responses to the cold test, and 1 case (6.67%) of M2 exhibited slow responses to the cold test. The distal gingival index of M2 was (0.5 ± 0.8) and the probing depth was (4.5 ± 1.9) mm (3 to 9 mm), with 3 cases (20%) of probing depth no less than 7mm and 4 cases (24.7%) of bleeding on probing. As shown on the cone-beam CT, the distal bone defect height of M2 was (0.2 ± 1.7) mm (-1.9 to 5.1 mm), with 1 case (6.67%) greater than 4mm. Seven cases (46.7%) of patients exhibited clear and continuous periodontal-ligament-gap-like structure at the interface between the root and the bone graft, of which 5 cases (33.3%) had blurred boundaries and 3 cases (20%) had irregular widening. In addition, 2 cases (13.33%) showed the deposition of cementum or alveolar bone-like mineralized tissues at the root where external resorption occurred, with the teeth restored to be conical-shaped.Conclusions For patients with M3-induced external root resorption of M2, M3 extraction together with socket grafting improves the pulpal and periodontal status. However, further histological studies are required to verify M2 root regeneration.