| Objective: Deformities result from hypoplasias of craniofa-cial skeleton and tumour therapyoperations are challenging andcomplex clinical problems. Distraction osteogenesis is playing arapidly expanding role in treatment of these difficult disease.Butthe long therapeutic period brought patients pain experience.Recent study focus on how to accelerate the regenerateossification, scholars have tried to use electry and ultrasoundstimulate or inject growth factor in distraction osteogenesis areato accelerate bone regeneration and gain expected results.Chinese tradition medicine have good effects on healing fracture,but no documents in accelerating regeneration following boneosteodistraction have been reported. This study was to investigatethe effect of chinese tradition medicine on bone regenerationossification following mandibular osteodistraction byestablishing a animal model of single mandibular distractionosteogenesis, and to determine the use of chinese traditionmedicine to shorten the healing period of regenerate bone.Method: Sixteen health goats were used in this study. Theywere randomly allocated into two groups of 8 goats each. GroupI: control group; Group II: experiment group. A customedcomponent distraction device was applied to one side ofmandible, and a transverse osteotomy was performed in allanimals. In group I Chinese tradition medicine was administratedfrom the latency phase to the consolidation phase and lasted forthe end of the experiment. Group II served as the control group.Distraction was started seven days after surgery at rate of 0.5mmevery 12 hours and continued for 10 days, result in a total of10mm of lengthing. After the activation period was completed,the distraction device was left in place for additional 28 days forbone consolidation in all animals. Then the animal was sacrificedand the mandible was harvested. The distraction area was cut inaxial plane. The upper half of the mandible was fixed in 10%neutral buffered formalin for 1 week at 4oC. After decalcification,the specimens was embedded in paraffin. The tissue section wasstained with hematoxylin and eosin at 4μm sections, andexamined under light microscope.The lower half of the mandiblewas fixed in 70% alcohol, then the bone specimens was directlycut into 9μm sections and kept for fluorescence measurement oftetracycline label. The surface area of bone trabeculae in eachmicroscopic field and the number of osteoblasts were counted byusing the image analysis software and the change of extendingbone formation was exposed.Result: 1 Clinical oberservation: All animals were able toundertake the experimental trauma. The weight of animal wasdeclined after surgery, and recovered after 1 week. After 10 daysdistraction, the anticipate bone extension was obtained. The chinwas turned to left, and the occlusion was disorder. 2 Specimenoberservation: There was bone regeneration in both groups. Thenew–bone combine with periosteum closely. Its surface wasrough, and the color was pale and had no luster. The new bonecovered up the splint of distractor. The average of extension was9.0mm. 3 X-ray: Postmortem radiographic examination afterconsolidation showed progressive calcification of the distractedarea between the mandibular segment of all groups. Four weeksafter distraction, the distracted zone in the experiment groupexhibited the higher radiodense opacity. 4.Histology: In thecontrol group, after 4 weeks consolidation, four zones exhibitedthe progress of intramembranous ossification. From center to theedge of distracted area there were the "zone of fibrouse tissue","zone of extending bone formation", "zone of boneremodeling"and "zone of mature bone". Extensive fibrosis andthe proliferation of osteoblasts forming osteoids were observed inthe distraction area. There was also a mixture of irregularlyshaped bone trabeculae formed by partial calcification at the edgeof the distracted area, although the centeral area of the distractionarea was filled with fibrous tissue. In the experiment group, after4 weeks consolidation, osteogenesis was observed. There wereabundant active osteoblasts and the bone trabeculae was formedin the distraction area, and fibrous tissue was little. Number ofosteoblasts was higher than control group. The trabeculae wasconnected to each other in cortical area. Irregularly shaped bonetrabeculae enhanced. There was osteoclast at the edge of... |
