Vale Francisco, Travassos Raquel, Martins João, Figueiredo José-Pedro, Marcelino João-Pedro, Francisco Inês
Institute of Orthodontics, Faculty of Medicine of the University of Coimbra, Portugal.
Hard Tissues Laboratory, Faculty of Medicine of the University of Coimbra, Portugal.
J Clin Exp Dent. 2021 Sep 1;13(9):e866-e872. doi: 10.4317/jced.58095. eCollection 2021 Sep.
The osteogenesis distraction technique applied to the craniofacial skeleton is an alternative treatment for dentofacial deformities. Despite the advantages of tooth-borne distractors, few studies have evaluated their clinical implementation in sagittal dentoskeletal deformities. This study aimed provide a radiographic assessment of the effect of two different activations of tooth-borne distraction in the lengthening of the mandible in canines.
Ten male beagle dogs, approximately one year old, were used for this experimental study. Three remained as a control group and seven underwent a mandibular tooth-borne distraction protocol with single daily activation in one hemimandible and two daily activations in the other, during ten days. The consolidation period took 12 weeks. Occlusal radiographs were performed immediately pre- and postoperatively.
After the distraction period, the host bone margins presented very well-defined outlines with regular contours. Concerning the consolidation period, between the second and fourth weeks, all hemimandibles showed small rectangular radiopaque regions with parallel orientation to the distraction axis. At the twelfth week, all hemimandibles presented an entire mineralization of the distraction gap with no axial deviations of the anterior and posterior host bone, nine of which with both margins showing corticalization.
Radiographic analysis showed bone regeneration in order to achieve the original bone architecture, especially in the group of multiple distraction. Tooth-borne distraction allowed successful sagittal lengthening of the mandible in a canine model. Orthodontics, osteogenesis, distraction, mandibular advancement, orthodontic appliance design.
应用于颅面骨骼的骨生成牵张技术是牙颌面畸形的一种替代治疗方法。尽管牙支持式牵张器具有诸多优势,但很少有研究评估其在矢状牙颌面骨骼畸形中的临床应用。本研究旨在通过影像学评估两种不同激活方式的牙支持式牵张对犬下颌骨延长的效果。
选用10只约1岁的雄性比格犬进行本实验研究。3只作为对照组,7只接受下颌牙支持式牵张方案,一侧半下颌每天激活1次,另一侧每天激活2次,持续10天。巩固期为12周。在术前和术后即刻拍摄咬合片。
牵张期后,宿主骨边缘轮廓清晰,形态规则。在巩固期,第2至4周时,所有半下颌均显示出与牵张轴平行的小矩形不透光区。在第12周时,所有半下颌的牵张间隙均完全矿化,前后宿主骨无轴向偏差,其中9个半下颌的两侧边缘均显示皮质化。
影像学分析显示骨再生以恢复原始骨结构,尤其是在多次牵张组。牙支持式牵张在犬模型中成功实现了下颌骨的矢状延长。正畸学、骨生成、牵张、下颌前伸、正畸矫治器设计。