Miyajima K, Shirakawa K, Tanida K
Department of Orthodontics, School of Dentistry, Aichi-Gakuin University, Nagoya, Japan.
Aichi Gakuin Daigaku Shigakkai Shi. 1990 Mar;28(1 Pt 1):251-7.
A case is here presented in which mandibular first molar was horizontally impacted under the submerged primary molar. The patient was an 8 year-old-boy referred from a general dentist through the Department of Pedodontics in this hospital, whose chief complaint was a horizontally impacted mandibular first molar. Skeletally, diagnosis revealed an Angle Class II Division 2 malocclusion. The impacted first molar was uprighted with a lingual arch and a utility arch following the extraction of the submerged primary molar. The submerged primary molar was probably ankylosed causing a locking of the first molar which rotated as the root formed. The result of rotation during forming twisted the roots of the first molar, which will make root canal treatment difficult if the pulp is infected in the future. It may concluded that dental arches should be carefully observed even in the deciduous dentition.
本文介绍了一例下颌第一磨牙水平阻生于乳牙下方的病例。该患者为一名8岁男孩，由普通牙医转诊至本院儿童牙科，其主要诉求为下颌第一磨牙水平阻生。骨骼检查诊断为安氏II类2分类错颌畸形。在拔除乳牙后，通过舌弓和功能弓将阻生的第一磨牙直立。乳牙可能发生了粘连，导致第一磨牙被锁住，随着牙根形成而发生旋转。牙根形成过程中的旋转导致第一磨牙牙根扭曲，如果未来牙髓感染，这将使根管治疗变得困难。可以得出结论，即使在乳牙列阶段，也应仔细观察牙弓情况。
