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

本文介绍一种新研制的X线摄颅器，用于大鼠、兔等动物的颅面实验研究。用丙烯酸树脂制成的头架为长方体，由带耳杆的U形固定弓和颏托组成。在固定小动物时，头部被耳杆和弓上的几个铝销牢牢地固定在颅顶上。该头影测量仪可一次固定拍摄头颅侧位片和轴位片，并对40只Wister大鼠头部进行了头影测量，证明该系统能对小动物头部进行精确的形态学观察，为检验该头影测量仪的准确性，对每只大鼠头部进行了X线片和干颅骨的对比测量。出乎意料的是，结果证明，一定量的削减大鼠的头部可能是由于脱水程序产生干燥的头骨。因此，当测量同一大鼠的一个断头和一个干燥颅骨时，干燥颅骨上的值的减少比率是高度相似的。用8只日本白色家兔进行不同速度的颅面牵引的比较研究。采用“格雷罗;威尔斯公司的颅面牵引器”进行渐进式和快速式两种牵引，通过头颅定位测量骨延长、骨化、复发等，并结合组织学研究，探讨周期性颅面测量。渐进组与快速组相比，牵张部位骨化时间明显延长，复发率（0.1*0.3mm<0.3*0.4mm）明显降低，冠状缝矢状面组织学表现相似。

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.