PURPOSE: The study aimed to evaluate dosage-dependent effects of irradiation on bone regeneration and established a radiation-compromised rabbit model of mandibular distraction osteogenesis. MATERIALS AND METHODS: Twenty-three rabbits were divided randomly into 7 groups. Group A served as the control group, whereas experimental groups B, C, D, E, F, and G received preoperative irradiation at doses of 6.5, 7.0, 7.5, 8.0, 8.5, and 9.0 Gy, respectively, for 5 fractions. After 1 month, all rabbits underwent osteotomy and distraction osteogenesis with 7 days of latency, 11 days of active distraction at a rate of 0.9 mm/d, and 4 weeks of consolidation; rabbit mandibles were subsequently subjected to histologic, radiographic, and micro-computed tomography analysis. RESULTS: With increasing doses of irradiation, bone regeneration was markedly hampered. Radiographically, the high-dose groups (8.5 and 9.0 Gy) presented obscure cortical lines. Histologically, in the 8.5- and 9.0-Gy groups, cortical bones were not completely formed, and in the medullary cavity, there existed a large amount of fibrous tissue. CONCLUSION: Radiotherapy compromises bone regeneration during distraction osteogenesis, and the adverse effect is dose dependent.
PURPOSE: The study aimed to evaluate dosage-dependent effects of irradiation on bone regeneration and established a radiation-compromised rabbit model of mandibular distraction osteogenesis. MATERIALS AND METHODS: Twenty-three rabbits were divided randomly into 7 groups. Group A served as the control group, whereas experimental groups B, C, D, E, F, and G received preoperative irradiation at doses of 6.5, 7.0, 7.5, 8.0, 8.5, and 9.0 Gy, respectively, for 5 fractions. After 1 month, all rabbits underwent osteotomy and distraction osteogenesis with 7 days of latency, 11 days of active distraction at a rate of 0.9 mm/d, and 4 weeks of consolidation; rabbit mandibles were subsequently subjected to histologic, radiographic, and micro-computed tomography analysis. RESULTS: With increasing doses of irradiation, bone regeneration was markedly hampered. Radiographically, the high-dose groups (8.5 and 9.0 Gy) presented obscure cortical lines. Histologically, in the 8.5- and 9.0-Gy groups, cortical bones were not completely formed, and in the medullary cavity, there existed a large amount of fibrous tissue. CONCLUSION: Radiotherapy compromises bone regeneration during distraction osteogenesis, and the adverse effect is dose dependent.
Authors: Mi Hyun Seo; Min Young Lee; Mi Young Eo; Suk Keun Lee; Kyung Mi Woo; Soung Min Kim Journal: J Korean Assoc Oral Maxillofac Surg Date: 2020-08-31
Authors: R Helmers; D M J Milstein; N F Straat; H M Rodermond; N A P Franken; C D Savci-Heijink; H H de Boer; J de Lange Journal: J Clin Transl Res Date: 2020-12-11