Department of Oral and Maxillofacial Surgery, Faculty of Dentistry, Erciyes University, Kayseri, Turkey.
Department of Oral and Maxillofacial Surgery, Faculty of Dentistry, Bezmialem Vakıf University, İstanbul, Turkey.
J Craniomaxillofac Surg. 2018 Mar;46(3):424-431. doi: 10.1016/j.jcms.2017.12.010. Epub 2017 Dec 18.
Class 3 malocclusions with maxillary deficiency, which are treated surgically and/or ordonotically, are common among adult patients. The aim of this study was to develop a three-directional bone-borne distractor that would allow the transverse expansion and sagittal advancement of the maxilla simultaneously.
Computed tomography images of a patient with maxillary deficiency were transmitted to a software program, and a distractor was designed with different sizes (D1, D2, D3) and manufactured from titanium alloy. Y-shape segmental osteotomies were performed on the model, and vertical bite forces were applied. The biomechanical properties were evaluated by using the finite element method.
The highest von Mises stress value on the body of the distractor was seen in D2 (D2>D3>D1), with 234 N bite forces. D2 had maximum stress distribution on maxillary bone under 234 N and 93 N (D2>D1>D3). No difference was found among the plastic deformation rates according to biomechanical test results.
A three-directional bone-borne palatal distractor was produced, and this distractor system can be used for the treatment of skeletal class 3 patients with maxillary hypoplasia for its advantages of shortening the overall treatment time and reducing the scar formation. However, further animal and clinical studies are essential to determine the biological response of soft and hard tissues.
上颌骨发育不足的 3 类错[牙合]畸形，常需要通过手术和/或正畸联合治疗。本研究旨在开发一种三维骨内牵张器，以实现上颌骨的横向扩展和矢状向前移动。
将上颌骨发育不足患者的 CT 图像传输到软件程序中，设计了不同尺寸（D1、D2、D3）的牵张器，由钛合金制成。在模型上进行 Y 形节段性骨切开术，并施加垂直咬合力。使用有限元法评估生物力学性能。
在 234N 咬合力下，D2 型牵张器（D2>D3>D1）的体部 Von Mises 应力值最高。在 234N 和 93N 下，D2 型在上颌骨上的最大应力分布（D2>D1>D3）。根据生物力学测试结果，塑性变形率没有差异。
制作了一种三维骨内腭部牵张器，该牵张器系统可用于治疗上颌骨发育不良的骨骼 3 类患者，因其具有缩短整体治疗时间和减少瘢痕形成的优点。然而，需要进一步的动物和临床研究来确定软组织和硬组织的生物反应。
