The British journal of oral & maxillofacial surgery
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Br J Oral Maxillofac Surg · Oct 2005
Healing of fractures in osteoporotic rat mandible shown by the expression of bone morphogenetic protein-2 and tumour necrosis factor-alpha.
We studied the healing process of mandibular closed fractures in osteoporotic rats using specific antibodies to bone morphogenetic protein-2 (BMP-2) and tumour necrosis factor-alpha (TNF-alpha). We confirmed the osteoporosis in rats after oophorectomy by micro-CT, and then caused unilateral closed fractures in the mandible and monitored the healing process after 7, 14, 21, and 28 days. Data were compared simultaneously with those from a group of rats that had a sham operation. ⋯ We conclude that the healing of fractures in osteoporotic bone is delayed about a week compared with controls. In the healing of fractures in osteoporotic bone, there were more osteoblasts and osteoclasts but there was a predominance of osteoclasts probably induced by TNFalpha. The prolonged phase of bone turnover with osteoclast predominance in the osteoporotic group is suggestive of the cause of delay in the healing of the fracture.