METHODS: The bilateral maxillary first premolars of five beagle dogs were extracted and bone defects were created. The right and left sides of the maxilla were randomly divided into control and experimental sides. On the experimental side, the maxillary second premolar was mesially moved into the position of the missing first premolar. On the control side, the second maxillary premolar was extracted. Six months later, the beagles were euthanized. Microcomputer tomography was used to analyze bone microstructure parameters, alveolar bone height and alveolar bone width of the regenerated bone. Histological analysis was performed by staining tissue sections with toluidine blue.
RESULTS: Median BV/TV values in the experimental group (81.78%) were significantly larger than those in the control group (35.67%; p = 0.04). Median Tb.Sp values in the experimental group (0.14 mm) were significantly lower than those in the control group (0.54 mm; p = 0.04). Median Tb.Th values in the experimental group (0.48 mm) were significantly higher than those in the control group (0.21 mm; p = 0.04). Median Tb.Pf values in the experimental group (0.65/mm) were significantly lower than those in the control group (3.15/mm; p = 0.04). There was no significant difference in the trabecular number (Tb.N) between the two groups (p = 0.23). The median alveolar bone height values in the experimental group (-0.81 mm) were significantly higher than those in the control group (-2.11 mm; p = 0.04) at a distance 5 mm from the mesial CEJ of the third premolar. The median alveolar bone height values in the experimental group (0.45 mm) were significantly higher than those in the control group (-1.70 mm; p = 0.04) at a distance 6 mm from the mesial CEJ of the third premolar. There was no significant difference in alveolar bone width when compared between the two groups (p > 0.05).
CONCLUSIONS: The newly formed edentulous area created by orthodontic treatment had more compact and thicker trabeculae than the extraction socket. Furthermore, the newly formed edentulous area had a greater alveolar bone height available for the placement of implants.
方法:拔除5只比格犬的双侧上颌第一前磨牙,制作骨缺损。上颌骨的右侧和左侧随机分为对照侧和实验侧。在实验方面,上颌第二前磨牙近中移动到缺失的第一前磨牙位置。在控制方面,拔除第二颗上颌前磨牙。六个月后,小猎犬被安乐死了.采用微机断层成像技术分析骨微结构参数,再生骨的牙槽骨高度和牙槽骨宽度。通过用甲苯胺蓝染色组织切片进行组织学分析。
结果:实验组的BV/TV中位数(81.78%)明显大于对照组(35.67%;p=0.04)。中值Tb。实验组的Sp值(0.14mm)明显低于对照组(0.54mm;p=0.04)。中值Tb。实验组的Th值(0.48mm)明显高于对照组(0.21mm;p=0.04)。中值Tb。实验组Pf值(0.65/mm)明显低于对照组(3.15/mm;p=0.04)。骨小梁数目(Tb。N)两组之间(p=0.23)。实验组(-0.81mm)的中牙槽骨高度值显着高于对照组(-2.11mm;p=0.04),距第三颗前磨牙的CEJ距离为5mm。在距第三颗前磨牙的CEJ内侧6mm处,实验组(0.45mm)的中位牙槽骨高度值显着高于对照组(-1.70mm;p=0.04)。两组牙槽骨宽度比较差异无统计学意义(p>0.05)。
结论:通过正畸治疗形成的新形成的缺牙区的小梁比拔牙槽更紧凑,更厚。此外,新形成的缺牙区有更大的牙槽骨高度可用于放置植入物。