Apoptosis-related factors in the epithelial components of dental follicles and dentigerous cysts associated with impacted third molars of the mandible.
OBJECTIVE
Radiolucencies adjacent to the crowns of impacted third molars can represent follicular remnants or cysts. To clarify the possible role of apoptosis-related factors in pericoronal odontogenic tissues, expression of Fas, bcl-2, and single-stranded DNA (ssDNA) was examined in epithelial components of dental follicles (DFs) and dentigerous cysts (DCs) associated with impacted third molars of the mandible. The results were compared with immunoreactivity for Ki-67, a marker of cell proliferation.


METHODS
Specimens of 80 DFs and 27 DCs were examined immunohistochemically using antibodies against Fas, bcl-2, ssDNA, and Ki-67.


RESULTS
Expression of Fas and ssDNA was detected in superficial epithelial cells of DFs and DCs. Expression of bcl-2 and Ki-67 was found in epithelial cells neighboring the basement membrane. The positive ratio of bcl-2 in DFs was significantly lower than that in DCs. ssDNA-positive cells were slightly more numerous in DFs, while Ki-67-positive cells were slightly more numerous in DCs. In DFs, epithelial tissues with proliferative rete processes showed significantly higher Ki-67 labeling than did those without proliferative rete processes. DFs with marked inflammatory changes showed slightly higher rates of ssDNA and Ki-67 positivity than did DFs without marked inflammation.


CONCLUSIONS
Apoptosis-related factors and proliferative marker differ between DFs and DCs. Apoptosis and cell proliferation may play a role in the pathogenesis of DCs. In DFs, expression of apoptosis-related factors and proliferative marker is most likely modulated by the morphologic characteristics of epithelial components as well as by inflammatory changes.
Edamatsu
Mitsuru
M
Division of Oral Surgery, Department of Oral Medicine and Surgery, Tohoku University Graduate School of Dentistry, Sendai, Japan. edamatsu@ma.catvy.ne.jp
Kumamoto
Hiroyuki
H
Ooya
Kiyoshi
K
Echigo
Seishi
S
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D017209:Apoptosis; D001485:Basement Membrane / Q000473:pathology; D049109:Cell Proliferation; D002648:Child; D004277:DNA, Single-Stranded / Q000032:analysis; D003795:Dental Sac / Q000473:pathology*; D003803:Dentigerous Cyst / Q000473:pathology*; D004847:Epithelial Cells / Q000473:pathology; D005260:Female; D006801:Humans; D007249:Inflammation / Q000473:pathology; D019394:Ki-67 Antigen / Q000032:analysis; D008297:Male; D008334:Mandible / Q000473:pathology; D008875:Middle Aged; D008964:Molar, Third / Q000473:pathology*; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000032:analysis; D014095:Tooth, Impacted / Q000473:pathology*; D019014:fas Receptor / Q000032:analysis
D004277:DNA, Single-Stranded; D019394:Ki-67 Antigen; D019253:Proto-Oncogene Proteins c-bcl-2; D019014:fas Receptor