A Study on the increase of supporting alveolar bone during intrusion of tooth

牙压低过程中牙槽骨支撑力增加的研究

• 批准号: 14571973
• 负责人: NAKAMURA Yoshiki
• 金额: $ 1.92万
• 依托单位: Tsurumi University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2002
• 资助国家: 日本
• 起止时间: 2002 至 2003
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-14571973/
• 关键词: tooth movement; Intrusion; alveolar bone; micro CT; Tetracycline; テトラサイクリン

Intrusion is one type of tooth movement and teeth are usually intruded by about two-four mm into the alveolar bone. I this situation, the alveolar crest is also resorbed, ad consequently the relationship between supporting alveolar bone and tooth is maintained. This is due to the supra-alveolar fibers which are stretched downward with the intruded tooth. Intrusion produces no increase of the supporting bone. In this study we attempted to increase the supporting bone during the intrusion of a tooth by cutting the supra-alveolar fibers (septotomy). Mandibular third premolars (P3) of beagle dogs were used as materials. The P3 on both side were intruded for 4 weeks with skeletal anchorage system. Septotomy was performed every weeks around the P3 on one side of the mandible. Some of the P3 used as controls. After the intrusion, the dogs were fixed with formalin, and P3 with the surrounding bone were dissected out, dehydrated, embedded in resin. Then the specimen were observed with micro CT. Three dimensional images of the alveolar bone of P3 was constructed. The control P3 (without intrusion) was evenly surrounded by the alveolar bone. After 4 weeks, the P3 was intruded by about 2 mm with buccal movement. The lingual alveolar bone height was same with that of the control. The buccal alveolar crest was moved downward and the alveolar bone height considerably decreased. P3 with septotomy showed different aspects. Width of lingual alveolar bone increased, though the location of alveolar crest was not changed. The location of the buccal alveolar crest moved upward, indicating the increase of the alveolar bone height. The results suggest that intrusion with septotomy induces the increase of supporting bone.

侵入是牙齿移动的一种类型，牙齿通常侵入牙槽骨约2 - 4 mm。在这种情况下，牙槽嵴也被吸收，因此保持了支撑牙槽骨和牙齿之间的关系。这是由于牙槽上纤维随着侵入的牙齿向下伸展。侵入不会增加支撑骨。在这项研究中，我们试图通过切断牙槽上纤维（中隔切开术）来增加牙齿侵入过程中的支撑骨。以Beagle犬下颌第三前磨牙为材料。用骨骼锚定系统侵入两侧P3 4周。在一侧下颌骨的P3周围每周进行一次鼻中隔切开术。一些P3用作对照。侵入后，用福尔马林固定，将P3与周围骨一起解剖出来，脱水，包埋在树脂中。然后用显微CT观察标本。建立P3牙槽骨三维图像。对照P3（无侵入）被牙槽骨均匀包围。4周后，随着颊侧运动，P3被压入约2 mm。舌侧牙槽骨高度与对照组相同。颊侧牙槽嵴下移，牙槽骨高度明显降低。P3与鼻中隔切开术表现不同。舌侧牙槽骨宽度增加，牙槽嵴位置不变。颊侧牙槽嵴位置上移，牙槽骨高度增加。结果提示，鼻中隔切开术可增加支撑骨。