Evaluation of teriparatide effect on healing of autografted mandibular defects in rats

Abstract

Objective: To evaluate the effects of short-term teriparatide administration on healing of autologous bone graft in mandibular critical-size defects.

Subjects and methods: A 5-mm mandibular bone defect was created and iliac bone graft was harvested in 135 rats. Rats were randomly divided into 3 groups of negative control (NC), control (C), and study (S). In groups S and C, iliac graft was placed in defect and 2 μg/kg/day teriparatide or saline, respectively, was administered for 20 days. In group NC, iliac graft was not transferred to the defect and saline was injected for 20 days. Twenty, 40, and 60 days after surgery, 15 rats in each group were euthanized and the healing process was histologically evaluated and scored using a grading system (1-6).

Results: In group NC, defects did not heal or were predominantly filled with fibrous tissue. At day 20, bone defects in both C and S groups contained a large area of graft particles, numerous collagen fibers and some areas of new trabeculae. At the day 40, defects in group S showed a larger bone graft area, more new bone formation, smaller connective tissue area, and a higher healing score compared to group C (P < 0.05). At day 60, most of the defect in group S was filled with graft particles and mature bone while in group C, new trabecular bone formation was still underway (P < 0.05).

Conclusion: Teriparatide therapy improves healing of bone defects reconstructed with autograft by reducing bone graft resorption and enhancing new bone formation and maturation.

Keywords: Animal study; Autologous graft; Bone defect; Healing; Teriparatide.