Changes in mineral content, mineral deposition and vascular supply of the mandible after osteotomy.

Circulatory and skeletal damage in the form of a vertical osteotomy of the mandible, proximal to the entry of the inferior alveolar artery and mandibular perforantes, alone or in combination with unilateral or bilateral mucoperiosteal reflections were undertaken on young growing rats. Changes in mineral content and mineral deposition in the hard tissues of the mandibles were studied using microradiography and by labelling with tetracycline and lead acetate. Microangiography was performed to evaluate changes in the vascular supply. Resorption of the compact bone was seen in the central part of the compact bone, in the lower border of the mandible and in the incisal part of the alveolar bone. There was resorption of the cementum and dentin in the molar teeth. Remodelling processes were seen in the compact bone starting from vascular channels and on the surface of the bone trabeculae, ten days after osteotomy. Microangiography revealed that there is a collateral vascular system existing across the midline via the symphysis region, via submucosal tissue, via the mucoperiosteal pedicle to the inferior border of the mandible and via the network of small vessels in the periodontal membrane. It was concluded that the circulation to the peripheral parts of the mandible could in part be kept up by a retrograde flow in the collateral systems when the main circulation had ceased.