Nerve and Vascular Regeneration in Bone Transport Osteogenesis

Abstract

ObjectiveTo evaluate blood vessel and nerve formation in mandibular regenerate bone reconstructed by distraction osteogenesis (DO).MethodsIn 10 dogs, a 30–40mm mandibular defect was created. A bone transport reconstruction device was used to create regenerate across the gap, using standard DO criteria, followed by 6 week of consolidation. Three implants were placed on the regenerate and control sides. One group (n=5) was left to heal for 12 weeks and the other (n=5) for 18 weeks. After sacrifice, regenerate and control bone was prepared for histology and n=2–3 slides/group were analyzed. One examiner blinded to the experiment counted numbers of blood vessels and nerves.ResultsRegenerate bone had significantly more blood vessels than control bone. Increased vascularity of the regenerate appeared to be due to the formation of new small blood vessels. Healing time had no effect on the number of blood vessels in the regenerate. Nerve number increased from 12 to 18 weeks for both groups. In the control group the number of small nerves increased; the regenerate group showed an increase in small and large nerves.ConclusionThe increased vascularity of the regenerate relates to new bone regeneration. Increased innervation of regenerate appears due to nerve generation in new bone, while in controls nerve damage due to implant placement might increase small nerve sprouting.Grant Funding Source: Supported by grants DE017259 and DE15437 from NIDCR