title: Effects of local and whole body irradiation on the appearance of osteoblasts during wound healing in tooth extraction sockets in rats.
abstract: Irradiation before tooth extraction delays wound healing in the alveolar socket. This study examined the influences of local and whole body irradiation before tooth extraction on appearance of osteoblasts in the alveolar bone of rat maxillary first molars because bone formation is observed at the initial phase of wound healing. Several osteoblasts were generated 3 days after tooth extraction, and the number of cells increased day by day. Morphological studies showed there were little differences between local irradiation and non-irradiated controls. In contrast, the extraction wound in the whole body irradiation group showed delayed healing, and there was poor granulation tissue and very few osteoblasts at the bottom of the socket. An ultrastructural study showed that the osteoblasts in the extraction socket of whole body irradiation rats were smaller, and had poorly developed organelles. Injection of bone marrow cells to whole body-irradiated animals immediately after tooth extraction partially restored the number of osteoblasts. New periosteal bone formations outside of sockets showed little delay in the whole body irradiation group. These findings suggest that bone formation in the wound healing of extraction socket requires bone marrow cells from hematopoietic organs such as the bone marrow as well as local sources around the alveolar socket, during the initial phase of wound healing.
authors.affiliation: Department of Radiological Life Sciences, Division of Medical Life sciences, Hirosaki University, Hokkaido 061-0293, Japan. hosokawa@cc.hirosaki-u.ac.jp
authors.forename: Yoichiro
authors.initials: Y
authors.lastname: Hosokawa
authors.forename: Yasunori
authors.initials: Y
authors.lastname: Sakakura
authors.forename: Kazuharu
authors.initials: K
authors.lastname: Irie
authors.forename: Kohsei
authors.initials: K
authors.lastname: Kudo
authors.forename: Ikuo
authors.initials: I
authors.lastname: Kashiwakura
mesh_terms: D000818:Animals; D002465:Cell Movement; D005347:Fibroblasts / Q000528:radiation effects; D006097:Granulation Tissue / Q000528:radiation effects; D006412:Hematopoietic Stem Cells / Q000473:pathology; D008297:Male; D008437:Maxilla / Q000473:pathology / Q000528:radiation effects; D008963:Molar; D010006:Osteoblasts / Q000528:radiation effects* / Q000648:ultrastructure; D010012:Osteogenesis / Q000528:radiation effects*; D010521:Periosteum / Q000528:radiation effects / Q000648:ultrastructure; D051381:Rats; D017208:Rats, Wistar; D014081:Tooth Extraction; D020390:Tooth Socket / Q000503:physiopathology / Q000528:radiation effects*; D014916:Whole-Body Irradiation; D014945:Wound Healing / Q000528:radiation effects*