Experimental mandibular fracture: effect on bone circulation and metabolism after treatment with anticoagulants

An experimental model was designed for the study of mandibular fracture healing in Sprague-Dawley rats. Healing and remodellation were studied by routine histology and the vascular supply of the mandible by micro-angiography. The blood supply to the body of the mandible was similar to that seen in long bones. The arterial vascular system appeared to be intimately involved with the formation of bone. The vessel configuration varied in relation to the progress of healing. The effect of heparin, dextran 40 and dextran 70 therapy to increase blood flow in the fracture region was tested. Dextrans had no effect on fracture healing whereas heparin induced an increased chondroid reaction in the callus. Serum alkaline phosphatase was measured as a marker for hard-tissue formation. The enzyme activity was reduced after fracture with a minimum activity three days after fracture.