摘要
目的:研究正畸力作用下,狗乳磨牙移动对恒牙胚以及恒牙萌出的影响。方法:选用健康15～16周龄雄性中国狗20只,左侧下颌为实验侧,右侧下颌为对照侧,以狗乳尖牙为支抗移动第二乳磨牙。观察正畸加力0d、7d、14d和21d后狗第二乳磨牙的移动以及第三恒前磨牙牙胚的变化。同时对乳牙牙周组织、恒牙牙胚的牙囊、周围牙槽骨进行组织学观察,并对牙槽骨内的破骨细胞进行计数。结果:正畸加力21d后,与对照侧相比,实验侧第二乳磨牙近移31.5%,X线片显示第三恒前磨牙牙胚位置与对照侧相比近移31.9%,二者有明显差异。恒牙萌出后近移30.3%。组织学观察:第二乳磨牙和第三恒前磨牙牙胚近中侧均见骨质吸收,可见破骨细胞;远中侧可见新骨形成。第三恒前磨牙牙胚牙囊近中侧纤维受压、变窄,远中侧纤维受到牵张、变宽。结论:正畸力移动乳牙对其继承恒牙的萌出具有诱导作用,可以使恒牙胚在牙槽骨中有同方向移动趋势,萌出位置改变。
Objective:To investigate effects of permanent tooth germ and eruption of premolar during primary molar movement in dog.Method:20 Chinese male dogs (15～16 weeks) were selected, and divided into 4 groups: 0 day、7 day、14 day and 21 day. The appliance was used between second primary molar and primary canine. The distances of second primary molar movement and third permanent premolar germ movement were measured. The number of osteoclast in alveolar bone was counted and compared. Histological changes around tooth germ were observed.Result:Compared with the control side,after 21 days, the distances of second primary molar movement and third pesmanent premolar germ were increased by 31.5% and 31.9% respectively in experimental side. Third permanent premolar erupted was moved mesially by 30.3%. The number of osteoclast in mesio alveolar bone was increased markedly. Bone remodel was observed around third permanent premolar germ.Conclusion:Primary tooth orthodontic movement may result in the movement of permanent tooth germ in alveolar bone at the same direction.
出处
《临床口腔医学杂志》
2005年第7期390-392,共3页
Journal of Clinical Stomatology
基金
国家自然科学基金资助项目(30400510)
关键词
乳牙正畸
恒牙胚
恒牙萌出
破骨细胞
primary tooth orthodontic movement
permanent tooth germ
permanent tooth eruption
osteoclast
