Microvascular changes during osseous healing after mandibular segmental resection

Abstract

In this study, the relationship between osseous hiealing and microvascular changes was investigated utilizing an osseous-microvascular corrosion casting specimen of mandibular segmental defects (5×3mm) made using an ultrasonic blade in the rabbit. Specimens were prepared at 1, 2, 3 and 4 weeks postoperatively, and studied under light and scanning electron microscopes. At 1 week, neovascularization arose from preexisting vessels of inferior alveolar artery and mandibular periosteum. New bone formation was first seen at the fundus of the defect, and newly-formed trabeculae spread richly between new sinusoidal capillaries. At 2 weeks, there were increased signs of vascularization at the fundus of the defect, and the sinusoidal capillaries gave rise to new capillarise that had independent lumina and formed an interconnected network. Newly formed trabeculae developed to establish a bridge between the cut ends of the defect. At 3 weeks, the new bone formation or deposition observed previously increased in thickness. At 4 weeks, the defects were filled with the newly-formed bone, which rose to the level of the mandibular border. The periosteal vascular network was gradually remodeled to a normal pattern.
It is concluded that microvasculature formed during all stages of osseous healing after mandibular segmental resection contributes to new bone formation and development. It is therefor beneficial to maintain the existing vessels of the inferior alveolar artery using an ultrasonic blade.