The Usefulness of Mandibular and Maxillary Bone Derived from Neural Crest as Bone Graft Substitutes

抄録

Autografts, which are commonly used for alveolar bone regeneration, often utilize the ilium and jaw bones as alternative bone graft materials. Maxillary and mandibular bones are developmentally derived from neural crest-derived cells (NCDCs), while the majority of trunk and limb bones are derived from mesoblast cells. Consequently, the host bone graft material might differ in developmental origin from the recipient bone. With such a potential mismatch in practical terms, it is unclear whether genuine jaw bone can be regenerated. We hypothesized that bones derived from NCDCs and mesoblast cells show different capacities for in vivo bone healing. To investigate this proposal, we undertook bone graft experiments using a murine model. We first perforated a 2-mm diameter area in both the frontal and parietal bones, which are derived from NCDCs and mesoblast cells, respectively; then we grafted various source materials into each bone defect. Mice were euthanized at 2 weeks after grafting, and histological analyses and immunohistochemistry were performed to evaluate differences in bone healing based on the various combinations of graft and recipient bones. The frontal bone was found to heal faster than the parietal bone. Parietal bone defects transplanted with maxillary and mandibular bone grafts exhibited closure, whereas iliac and femoral bone grafts did not result in full healing. Immunostaining for osteopontin also demonstrated good bone regeneration in the parietal bone defects using maxillary and mandibular bone graft materials. These results suggest that maxilla and mandible bones exhibit NCDC properties with an enhanced healing potential. We conclude that maxillary and mandibular bones are effective bone graft and graft bed materials.