After 1 and 4 weeks, 4 dogs in the experimental group and 2 dogs in the control group were killed respectively to observe the maxillary suture, palatine suture, malomaxillary suture and zygomaticotemporal suture grossly and histologically. 牵引1周和4周时,各处死实验组犬4只和对照组犬2只,对前颌缝,腭横缝,颧颌缝,颧颞缝区组织作大体观察和组织学观察。