Journal of Dental Research, Vol 70, 1462-1466, Copyright © 1991 by International & American Associations for Dental Research Online Journals
Age-related development of the long-junctional epithelium in the senescence-accelerated mouse
M. Sashima, M. Satoh and A. Suzuki
Department of Oral Pathology, School of Dentistry, Iwate Medical University, Japan.
The mesial gingiva of the maxillary first molar of SAM-R/1/Iw
(senescence-accelerated mouse, resistant/1/Iwate) and the P/2/Iw
(prone/2/Iwate) were studied morphologically by quantitative and
qualitative methods as a function of age (one-, two-, six-, 12-, and
16-month-old). In this region, neither plaque nor periodontitis has been
found (Sashima et al., 1990a). Statistical analyses of the gingival tissues
in this region in both strains showed that, with age, the length of the
junctional epithelium (JED) increased, the depth of the gingival sulcus
(GSD) did not change, and the height of the gingival crest (GCD) decreased.
Therefore, long-junctional epithelium developed, and gingival recession
occurred, since a periodontal pocket did not develop with age in either
strain. In particular, there was a strong correlation between the JED and
age in both strains (r = 0.84, p less than 0.05 for the R/1/Iw, and r =
0.92, p less than 0.05 for the P/2/Iw). The JED, GSD, and GCD of the P/2/Iw
were higher than each of those in the R/1/Iw after six months of age;
however, there were no significant differences between the R/1/Iw and the
P/2/Iw for any age group (one-, two-, six-, 12-, and 16-month-old).
