Tooth eruption in vascularized allogenic mandible of dog

We examined whether tooth eruption would occur normally in grafted allogeneic mandibular bone.Using vascularized composite tissue transplantation, we extracted portions of immature mandibles including the tooth germs from young beagle dogs and transplanted them into unrelated immature or mature beagle dogs. In addition, we prepared vascularized gingival flaps from mature dogs and grafted them onto the mandibles of unrelated immature dogs. Mandibular bone including tooth germs without covering gingiva from immature dogs was also transplanted either to immature or mature recipient dogs, and the grafted bones were covered with recipients' gingiva. Then, we examined tooth eruption in these grafted mandibular bones.Normal tooth eruption was observed only in the mandibles transplanted to the young recipient dogs. In the mature dogs, tooth eruption from the gingiva was delayed; the whole crown was covered with a cap of gingival tissue, which was not a gingival overgrowth.It is suggested that tooth eruption depends on the age of the recipient, regardless of the overlying gingival tissues transplanted.