Bell W H, Gonzalez M, Samchukov M L, Guerrero C A
Department of Oral and Maxillofacial Surgery, Baylor College of Dentistry, The Texas A&M University System, Dallas 75266-0677, USA.
J Oral Maxillofac Surg. 1999 May;57(5):548-62; discussion 563. doi: 10.1016/s0278-2391(99)90074-5.
The purpose of this study was to analyze the skeletal and dental positional changes and histomorphology of the distraction regenerates and mucogingival periosteal tissues that occurred after simultaneous widening and bilateral lengthening of the mandible in baboons by a miniaturized intraoral bone-borne distraction appliance.
Distraction appliances were activated 5 days after vertical ramus and symphyseal osteotomies at a rate of 0.9 mm/d for 10 days. The appliances were then stabilized for 8 weeks, after which the animals were killed. The distraction gaps and gingival tissues were analyzed clinically, histologically, and by standardized radiographic studies.
Positional changes of the canines and incisor apices were proportional to the skeletal movements. Tipping of both incisors toward the center of the distraction gap was observed. Proportionate movement of the superior and inferior portion of the distracted segments was noted. Newly formed longitudinal trabecular columns parallel to the vector of distraction originated from the intact margins of alveolar bone contiguous with the adjacent teeth. Active histogenesis occurred in the stretched mucogingival periosteal tissues located in the distraction gaps.
The results of this investigation support the clinical use of the miniaturized intraoral bone-borne distraction appliance to selectively widen and lengthen the mandible. The orientation of the mandibular distractors must be parallel to the common vector of distraction, which should be parallel to the maxillary occlusal plane. The formation of a bone regenerate in the alveolar region depends on the presence of an adequate bone interface on either side of the distraction gap.
本研究的目的是分析通过小型化口内骨支持式牵张矫治器对狒狒下颌骨进行同期扩宽和双侧延长后，牵张再生组织以及黏膜牙龈骨膜组织的骨骼和牙齿位置变化及组织形态学。
在垂直升支和下颌骨联合处截骨术后5天激活牵张矫治器，以0.9mm/天的速率持续10天。然后将矫治器固定8周，之后处死动物。对牵张间隙和牙龈组织进行临床、组织学及标准化影像学研究分析。
犬牙和切牙根尖的位置变化与骨骼移动成比例。观察到两颗切牙均向牵张间隙中心倾斜。注意到牵张节段的上下部分有相应移动。与相邻牙齿相连的牙槽骨完整边缘产生了平行于牵张向量的新形成的纵向小梁柱。位于牵张间隙的拉伸黏膜牙龈骨膜组织中发生了活跃的组织发生。
本研究结果支持小型化口内骨支持式牵张矫治器在临床上用于选择性地扩宽和延长下颌骨。下颌牵张器的方向必须与牵张的共同向量平行，该向量应与上颌咬合平面平行。牙槽区域骨再生的形成取决于牵张间隙两侧是否存在足够的骨界面。
