Bone defects in the growing period give rise to mandibular growth obstruction. After the bone is resected, the defect in the mandible is reconstructed by means of bone graft or ceramic implantation to maintain mandible form and function, but the effect on mandibular growth has not been studied in detail. So the author has studied experimentally the effects of bone graft and the implantation of 2 types of ceramics, hydroxylapatite (HA) and tricarcium phosphate (TCP), in surgically caused mandible defects growth.
Ninety-six 4-week-old WKA rats were used in this study. Of these 36 rats were used for histological study and 60 were divided equally into the 6 following groups: Group 1. Bone was grafted into the defect at the mandibular body inferior border. Group 2. Bone was grafted into the defect at the mandibular ramus center. Group 3. Fibrin adhesion system (Tisseel ® kit) was filled into the bone defect created the same as in group 1. Group 4. Bone was grafted with fibrin adhesion system into the bone defect created the same as in group 1. Group 5. HA was implanted with fibrin adhesion system into the bone defect created the same as in group 1. Group 6. TCP was implanted with fibrin adhesion system into the defect created the same as in group 1. Sixty of the rats were sacrified at 15 weeks of age, decapitated, and the obtained specimens were evaluated by measurement, contact microradiography and radiography.
Growth inhibition of the mandible after resection of the mandible inferior border was significantly improved by replantation of the removed bone itself to the resected site, but there was no significant effect on mandible growth when the defect at the mandibular ramus center was filled with bone. Ceramics implantation into the defect of the mandible inferior border showed a similar but not significant effect to that seen in the case of bone replantation.