title: Influence of aging on tooth eruption: experimental canine mandibular allograft.
abstract: OBJECTIVE
  Aging is clinically related to tooth eruption; however, there are no known studies that have elucidated the relationship. We examined whether tooth eruption would occur normally in a mature subject.
  
  
  METHODS
  Using vascularized composite tissue mandibular transplantation, we extracted portions of immature mandibles including the tooth germs from young beagle dogs and placed them into unrelated immature and mature beagle dogs. We then examined eruption of the lower first molar in the grafted mandibular bone and compared the results clinically, radiographically, and histologically.
  
  
  RESULTS
  Normal tooth eruption was observed in the transplanted mandibles in the young dogs. In the mature dogs, eruption from the gingiva was delayed, whereas that from alveolar bone occurred normally in the transplanted mandibles. Further, the whole crown was covered with a cap of gingival tissue in the mature dogs, although this cap was not gingival overgrowth.
  
  
  CONCLUSIONS
  Tooth eruption is influenced by some unknown factors related to aging. Apparently, apoptosis did not occur in the connective tissues between the reduced enamel epithelia and oral epithelia that overlay the teeth in the mature subjects.
authors.affiliation: First Department of Oral and Maxillofacial Surgery, Osaka University, Graduate School of Dentistry, Suita City, Japan. tanaemi@dent.osaka-u.ac.jp
authors.forename: Emiko
authors.initials: E
authors.lastname: Tanaka
authors.forename: Munehiro
authors.initials: M
authors.lastname: Hamaguchi
authors.forename: Yumi
authors.initials: Y
authors.lastname: Eguchi
authors.forename: Shoichiro
authors.initials: S
authors.lastname: Ishii
authors.forename: Toyomi
authors.initials: T
authors.lastname: Okauchi
authors.forename: Tomonao
authors.initials: T
authors.lastname: Aikawa
authors.forename: Mikihiko
authors.initials: M
authors.lastname: Kogo
mesh_terms: D000375:Aging / Q000502:physiology*; D000539:Alveolar Process / Q000473:pathology / Q000503:physiopathology; D000818:Animals; D004285:Dogs; D004658:Enamel Organ / Q000473:pathology / Q000503:physiopathology; D004848:Epithelium / Q000473:pathology / Q000503:physiopathology; D005881:Gingiva / Q000473:pathology / Q000503:physiopathology; D008334:Mandible / Q000473:pathology / Q000637:transplantation*; D008963:Molar / Q000473:pathology / Q000503:physiopathology; D009805:Odontogenesis / Q000502:physiology; D014057:Tomography, X-Ray Computed; D014078:Tooth Eruption / Q000502:physiology*; D014083:Tooth Germ / Q000473:pathology / Q000503:physiopathology / Q000637:transplantation*; D014094:Tooth, Deciduous / Q000503:physiopathology / Q000637:transplantation; D014184:Transplantation, Homologous