Experimental Study on Craniofacial Distraction-Endoscopic Surgery and Periodical Investigation with Cephalometer for Small Animals-

研制了一种新的X线片头影定位器，用于动物(如Wistar大鼠或兔)的实验性颅面研究。由丙烯酸树脂制成的定头器为长方形平行六面体，由带耳杆的U形固定弓和下巴靠背组成。在固定小动物时，头部由耳杆和弓上粘在头顶上的几个铝销牢牢抓住。通过对40只Wistar大鼠头部进行头影测量，证明该系统能对小动物头部进行精确的形态观察。为了检验头影测量的准确性，对每只大鼠的头部进行了X线片和干头骨的对比测量。出乎意料的是，结果证明，一定量的大鼠头可能是因为脱水程序造成的头骨干燥。因此，在测量同一只大鼠的干燥头骨和干燥头骨时，干燥头骨上的数值缩减率是高度可考虑的。8只日本大白兔在不同牵张速度下进行颅面牵张的比较研究。使用‘Guerrero；Wells公司颅面牵张器’的双冠状牵张器进行渐进式牵张和快速牵张术，通过对骨延长、骨化、复发等的头影测量和组织学研究，研究牙周头面部测量。渐进式组牵张部位的骨化时间明显长于快速组，复发较小(0.1×0.3 mm；0.3×0.4 mm)，冠状缝合矢状面的组织学表现与快速组相似。

A new roentogenographic cephalostat has been developed for the investigation of the experimental craniofacial research using animals, such as Wister rats or rabbits. The cephalostat made of acrylic resin is rectangular parallelepiped and consists of U-shaped fixation bow with ear rods and chin rest. In fixation of a small animal, the head is firmly held by ear rods and several aluminum pins on the bow that stick to cranial vault. The lateral and axial cephalogram can be taken in one time fixation with the cephalometer and 40 heads of Wister rat were applied and cephalometrically measured, which proved that the system enable to make precise morphological observation of the samll animal head.In order to examine the acuracy of the cephalostat, comparative measurements of X-ray film and dry skull were done on each rat's head. Unexpectedly, results proved that certain amount of curtailment of rat's heads probably because of dehydrative procedure creating the dry skull. So that when measuring a cuthead and a dry skull in the same rat, reduction ratio of the value on the dry skull is highly considerable.A comparative study of the craniofacial distraction by a different speed of distraction using 8 Japanese white rabbits. A gradual distraction and a rapid distraction are perfomed with the bi-coronal distraction using 'Guerrero ; Wells Co.Craniofacial Distractor', investigating a perodical craniofacial cephalometry by means of the cephalostat measurement of bone elongation, ossification, relapse and so on, and histological study. The gradual group had a significantly longer ossification and a smaller relapse(0.1*0.3mm<0.3*0.4mm) on the distraction site than the rapid group and similar findings were shown on a histology of sagittal section of the coronal suture.