Chang Hao-Hueng, Tseng Hui, Hsieh Thomas Mon-Hsian, Huang Chi-Ying, Chen Yuan-Hou, Hsu Chao-Yu, Cheng Wei-Ming, Chen Min-Huey, Chen Shu-Ru, Yao Chung-Chen Jane
Department of Oral and Maxillofacial Surgery, National Taiwan University Hospital, School of Dentistry, College of Medicine, National Taiwan University, Taipei, Taiwan.
Plast Reconstr Surg. 2005 Jun;115(7):2014-24. doi: 10.1097/01.prs.0000163326.63031.30.
The purpose of the study was to investigate the morphologic changes of distraction osteogenesis performed on the mandible in growing minipigs.
Eighteen piglets were divided into four groups. In group A (n = 6), animals received unilateral osteotomy and the distractor device was activated for 2 weeks after a 1-week latency period. In group B (n = 6), animals underwent the osteotomy procedure and distractor placement. In group C (n = 3), animals received the distractor, and in group D (n = 3), only four reference pins were placed. After completion of distraction, the head portions were sent for computed tomography scanning. The coordinates of each selected mandibular landmark were recorded on three-dimensional computed tomographic reconstruction images for further mathematical linear and angular measurements to quantify morphologic changes.
The sagittal length related to gonial region was increased in group A but decreased in group B. Although all groups had the tendency of increased ramus width, it was only significant in group B. The distraction also reduced the gonial angle and elevated the ramus inclination to the Frankfort horizontal plane at the operated side. On the contrary, osteotomy alone opened the gonial angle and flattened the ramus inclination.
Distraction could lengthen the mandibles in growing minipigs by reducing the gonial angle and displacing the mandible posteriorly. This effect, which allows for developing a prominent gonial angle, could be further explored in treating syndromic patients with the deficiency in the gonial region. A greater amount of overcorrection should be considered while treating growing patients because the mandibular osteotomy procedure itself seems to retard the growth.
本研究的目的是调查在生长中的小型猪下颌骨上进行牵张成骨的形态学变化。
18只仔猪被分为四组。A组（n = 6），动物接受单侧截骨术，在1周的潜伏期后，牵张器装置激活2周。B组（n = 6），动物接受截骨术并放置牵张器。C组（n = 3），动物接受牵张器，D组（n = 3），仅放置四个参考针。牵张完成后，将头部送去进行计算机断层扫描。在三维计算机断层扫描重建图像上记录每个选定下颌骨标志点的坐标，以便进行进一步的数学线性和角度测量，以量化形态学变化。
A组与下颌角区域相关的矢状长度增加，而B组减少。尽管所有组都有下颌支宽度增加的趋势，但仅在B组中显著。牵张还减小了下颌角，并提高了手术侧下颌支相对于法兰克福水平面的倾斜度。相反，单纯截骨术则打开了下颌角并使下颌支倾斜度变平。
牵张可通过减小下颌角并将下颌骨向后移位来延长生长中小型猪的下颌骨。这种允许形成明显下颌角的效果，可在治疗下颌角区域发育不足的综合征患者中进一步探索。在治疗生长中的患者时应考虑更大程度地过度矫正，因为下颌骨截骨术本身似乎会阻碍生长。
