The Impact of the Demineralized Bone Matrix on the Quality of the Bone Regeneration and the Duration of Consolidation Period in the Rat Mandibular Distraction Osteogenesis Model

Distraction Osteogenesis (DO) is the long-term treatment method used for craniyofacial pathologies. In this study, we aimed to investigate the accelerating effect of demineralized bone matrix upon the physiologic process of consolidation period of DO and its sustaining effect upon bone quality.Forty Wistar type male rats weighting between 250-300 grams were used in the study. All subjects were operated on the right hemimandibula. The soft tissue up to the bone was cut and sutured in the operative control group (group 3 n=8). The remaining subjects were divided into two groups and DBM (group 1, n=16) and %0.09 NaCl (group 2, n=16) groups were formed. Distractor devices were fixed to both groups. After osteotomy, 5 day?s latency, the rate of 0,25 milimeters and twice a day as a rhythm with a distraction of 3 milimeters were performed. Later, on the first day of the four weeks? consolidation period DBM was applied to the distraction gap and %0.09 NaCl was applied to the other group. Eight subjects from both groups were sacrificed in the second week of the consolidation and their right hemimandibula were taken for histologic examination. In the fourth week of the consolidation the remaining all subjects were sacrificed and hemimandibulectomies were performed. Bone mineral densitometric (BMD) histologic and immunohistochemistrical examinations were made. In histological examination H.E., Masson?s-trichrome, MMPase-2 ve Caspase-3 were used to examine healing of bone and apoptosis. In the second and fourth weeks, histological examinations and bone densitometric data were statistically evaluated by using Kruskal-Wallis method. BMD results were also evaluated with Mann Whitney-U test in binary groups. In the histological evaluation, at the second and fourth weeks it was seen that the bone healing results and cellular activities of the group with the DBM application were relatively better than those of the group with %0.09 NaCl application and it was also realized that there was a statistically significant difference (p<0,05, Mann Whitney-U). According to 1/3 BMD results, there was a significant difference among three groups; however, in binary comparisons, despite the fact that DBM group had relatively better results than %0.09NaCl group, there was no statistically difference.(p>0.05, MannWhitney-U)In conclusion, the results, regarding to bone healing process are statistically significant and show that healing process is accelerated and affected in a positive way with application of the DBM which is convenient for clinical use, to distracted zone at the beginning of the consolidation phase. These results also show that application of the DBM without general anesthesia, during treatment period, may be preferred by the surgeons to support the healing process of the craniofacial cases that may require distraction.