Private practice.
Department of Orthodontics, The Institute of Craniofacial Deformity, Yonsei University College of Dentistry, Seoul, Korea.
J Periodontol. 2019 Jan;90(1):35-43. doi: 10.1002/JPER.18-0034. Epub 2018 Aug 30.
Labially impacted maxillary canines may lack periodontal tissue after orthodontic traction. This study evaluated the periodontal status of labially impacted maxillary canines after the closed eruption technique followed by orthodontic traction and investigated pretreatment variables affecting periodontal changes.
Patients with one labially impacted maxillary canine (impaction group) and one contralateral normal canine (control group) were selected retrospectively. Maxillary canine pretreatment variables (angle, depth, sector, and Nolla stage) were determined from initial panoramic radiography. Periodontal outcomes including sulcus probing depth, bone probing depth, keratinized gingiva width (KGW), attached gingiva width (AGW), clinical crown length (CCL), cemento-enamel junction to alveolar crest (CEJ-AC) distance, root length, and bone support were measured from radiographic and clinical examinations after treatment and compared between the two groups. Pretreatment variables affecting the periodontal outcomes were determined using linear regression analyses.
Fifty-four patients (21 males and 33 females; mean age, 12.85 years) were enrolled. The KGW, AGW, and root length were shorter; the CCL and CEJ-AC distance were longer; and the bone support on the interproximal sides was less in the impaction group than in the control group (P < 0.05). The root length was shorter with higher Nolla stages and the distal alveolar crest was lower with deep and mesially angulated impaction (P < 0.01).
After the closed eruption technique, impacted canines exhibited slight but clinically insignificant periodontal recession compared with the contralateral normal tooth. The root developmental stage and pretreatment depth and angle may influence periodontal recession.
唇向埋伏的上颌尖牙在正畸牵引后可能缺乏牙周组织。本研究评估了经闭合式萌出技术联合正畸牵引治疗后唇向埋伏上颌尖牙的牙周状况，并探讨了影响牙周变化的治疗前变量。
回顾性选择了 1 例唇向埋伏上颌尖牙（埋伏组）和 1 例对侧正常尖牙（对照组）患者。从初始全景片确定上颌尖牙的治疗前变量（角度、深度、象限和 Nolla 分期）。治疗后通过放射学和临床检查测量牙周结局，包括龈沟探诊深度、骨探诊深度、角化龈宽度（KGW）、附着龈宽度（AGW）、临床冠长度（CCL）、牙釉质牙骨质界到牙槽嵴（CEJ-AC）距离、牙根长度和骨支持，并比较两组间的差异。使用线性回归分析确定影响牙周结局的治疗前变量。
共纳入 54 例患者（男 21 例，女 33 例；平均年龄 12.85 岁）。埋伏组的 KGW、AGW 和牙根长度较短，CCL 和 CEJ-AC 距离较长，近中侧骨支持较少（P<0.05）。Nolla 分期越高，牙根长度越短，近中牙槽嵴越低，埋伏牙深度和近中角度越大（P<0.01）。
与对侧正常牙相比，经闭合式萌出技术后，埋伏牙的牙周略有但临床无显著退缩。牙根发育阶段以及治疗前的深度和角度可能影响牙周退缩。
