Oltramari Paula Vanessa Pedron, de Lima Navarro Ricardo, Henriques José Fernando Castanha, Taga Rumio, Cestari Tania Mary, Ceolin Daniele Santi, Janson Guilherme, Granjeiro José Mauro
Department of Orthodontics, Bauru Dental School, University of São Paulo, Bauru, Brazil.
Am J Orthod Dentofacial Orthop. 2007 Mar;131(3):302.e10-7. doi: 10.1016/j.ajodo.2006.07.020.
In this study, we investigated whether it is possible to orthodontically move a tooth into an adjacent bone defect previously filled with xenogenic grafting material, with emphasis on the reactions of the tooth roots and adjacent tissues.
Six minipigs were used. In each animal, 4 defects were created at the mesial aspects of the maxillary and mandibular first permanent molars; the defects on the right were filled with the xenograft (test side), and the opposite defects (control side) were filled with blood clots and allowed to heal spontaneously. Three months later, orthodontic appliances were placed in each quadrant to allow mesial bodily movement of the first permanent molars. When the teeth were moved about halfway into the defect spaces, the animals were killed, and the areas of interest were harvested. The mesial roots of the first molars and adjacent tissues were histologically and morphometrically evaluated. The volume density of bone tissue, the percentage of root resorption, and the bone height were evaluated with image analysis software.
Data analysis showed that (1) the percentage of root resorption was smaller (P = .0359) for the test group (4.16%) compared with the control (6.52%); (2) there was no statistically significant differences between groups concerning the volume density of neoformed bone (P >.05); (3) the bovine bone matrix was almost totally replaced by structured bone tissue; (4) the test group had a statistically significant smaller bone height loss (2.18 mm, P = .0018) than the control group (3.26 mm).
Based on these results, it was concluded that teeth can be moved into areas of bone defects previously filled with xenograft.
在本研究中，我们调查了是否有可能通过正畸方式将牙齿移动到先前填充有异种移植材料的相邻骨缺损处，重点关注牙根和相邻组织的反应。
使用6只小型猪。在每只动物的上颌和下颌第一恒磨牙近中侧制造4个缺损；右侧的缺损用异种移植物填充（试验侧），相对的缺损（对照侧）用血凝块填充并任其自发愈合。3个月后，在每个象限放置正畸矫治器，使第一恒磨牙整体向近中移动。当牙齿移动到缺损空间大约一半时，处死动物并获取感兴趣的区域。对第一磨牙的近中牙根和相邻组织进行组织学和形态计量学评估。使用图像分析软件评估骨组织的体积密度、牙根吸收百分比和骨高度。
数据分析表明：（1）试验组（4.16%）的牙根吸收百分比低于对照组（6.52%）（P = 0.0359）；（2）两组之间新形成骨的体积密度无统计学显著差异（P > 0.05）；（3）牛骨基质几乎完全被结构化骨组织替代；（4）试验组的骨高度损失（2.18 mm，P = 0.0018）比对照组（3.26 mm）有统计学显著降低。
基于这些结果，得出结论：牙齿可以移动到先前填充有异种移植物的骨缺损区域。
