J Korean Assoc Oral Maxillofac Surg.  2003 Apr;29(2):79-85.

Histopathologic changes of the craniomandibular joint according to the amount of distraction after 6 weeks of distraction osteogenesis in rabbits

• Kim HH
• Kim SG
• Lim SC
• Chung HM
• Kim SG

Abstract

The purpose of this study is to observe histopathologic changes in the bilateral craniomandibular joints after allowing 6 weeks of consolidation by varying the amount of distraction in rabbit mandible. Eight rabbits weighing about 2 to 3kg were used. After corticotomy was performed on the left mandibular body between the first premolar and the second premolar region, a unilateral fixation device was placed. Then, a 7-day period was allowed without distraction of the device. The mandible was lengthened 0.5mm/day. Corticotomy and lengthening of mandible were not performed in control group. After the completion of the lengthening process, a 6-week-consolidation period was allowed. Then, the rabbits were sacrificed, and histologic examination of the craniomandibular joints was performed. Proliferative changes were observed in the craniomandibular joints in all groups. With the increasing amount of distraction, hypertrophy of the cartilage layer became more severe, bone formed was dense and enchondral ossification was clearly shown in subchondral bone. Hypertrophy of the cartilage layer was also seen in the non-distracted side as the distracted side in the experimental group. These results indicate that when physical force is applied constantly to joints, the proliferation of articular cartilage and bone formation are present. When more than 6 weeks of consolidation period is allowed at the time of performing distraction for more than 5mm, articular changes, especially, in the contralateral side should also be noted.

MeSH Terms

Bicuspid
Cartilage
Cartilage, Articular
Hypertrophy
Joints*
Mandible
Osteogenesis
Osteogenesis, Distraction*
Rabbits*