title: Occlusal tooth wear in male F344/N rats with aging.
abstract: With the aim of clarifying the aging properties of an animal model, the progress of occlusal tooth wear (OTW) of molars in male F344/N rats was monitored. Dried maxilla and mandible specimens from 61 male F344/N rats, aged 7 to >30 months, were used. The levels of OTW of all molars were monitored with aging. The cuspis dentis of molar teeth were worn out by 7 months (M) of age, and the occlusal surface became flat. As for each molar tooth (M(1-3), numbered in accordance with its position), OTW of M(1) was more severe in the lower than in the upper jaw, whereas M(3) was more severe in the upper than the lower jaw. OTW of M(2) in both the upper and the lower jaws progressed rapidly after 27M. OTW in male F344/N rats progressed faster than in females. However, when compensated for life span, both genders had similar profiles in OTW progress with aging. This study suggested that male rats were more convenient than females as a model for gerodontological research because of the earlier course of OTW progress.
authors.affiliation: Animal Facility for Aging Research, National Institute for Longevity Sciences, National Center for Geriatrics and Gerontology, Morioka-cho, Obu, Japan. kazz@nils.go.jp
authors.forename: Kazutoshi
authors.initials: K
authors.lastname: Nishijima
authors.forename: Sachi
authors.initials: S
authors.lastname: Kuwahara
authors.forename: Tamio
authors.initials: T
authors.lastname: Ohno
authors.forename: Osamu
authors.initials: O
authors.lastname: Miyaishi
authors.forename: Yoshitake
authors.initials: Y
authors.lastname: Ito
authors.forename: Yasunori
authors.initials: Y
authors.lastname: Sumi
authors.forename: Shin
authors.initials: S
authors.lastname: Tanaka
mesh_terms: D000375:Aging / Q000473:pathology*; D000818:Animals; D006801:Humans; D008297:Male; D008954:Models, Biological; D008963:Molar / Q000473:pathology; D051381:Rats; D011916:Rats, Inbred F344; D012737:Sex Factors; D019217:Tooth Attrition / Q000473:pathology*