Gound Tom G, Maixner David
Postgraduate Endodontics, University of Nebraska College of Dentistry, 40th and Holdrege Streets, Lincoln, NE 68583, USA.
J Endod. 2004 Jun;30(6):448-51. doi: 10.1097/00004770-200406000-00018.
Type III dens invaginatus is a developmental anomaly characterized by an enamel-lined channel that originates on the coronal surface and passes apically through part or all of the root and exits into the periodontal ligament. In this case report, a 13-yr-old male had a Type III dens that exited at the midroot level of tooth #7. At that same level, the root dilacerated severely to the mesial, and a periradicular radiolucency was present on the distal. A 12-mm periodontal defect was present on tooth #6 and a sinus tract was present. All maxillary anterior teeth responded normally to pulp vitality testing, and no other abnormal probing depths were present. The channel opening in the crown was located, and the channel was negotiated, enlarged, and filled with calcium hydroxide. Thirteen weeks later, the probing was normal and the canal was obturated with gutta-percha and restored. Two- and 6-yr recalls showed complete healing of the bony defects and continued normal responses to vitality testing.
III型牙内陷是一种发育异常，其特征为有一条内衬釉质的管道，该管道始于牙冠表面，向根尖方向穿过部分或全部牙根，并通向牙周膜。在本病例报告中，一名13岁男性的III型牙内陷在7号牙牙根中部水平穿出。在同一水平，牙根严重向近中弯曲，远中存在根尖周透射区。6号牙有12毫米的牙周缺损且有窦道。所有上颌前牙牙髓活力测试反应正常，未发现其他异常探诊深度。确定了牙冠上的管道开口，对管道进行了疏通、扩大，并充填了氢氧化钙。13周后，探诊正常，根管用牙胶尖充填并进行了修复。2年和6年的复查显示骨缺损完全愈合，牙髓活力测试持续正常反应。
