Differential Localization of ODAM in Periodontitis with Similar Clinical Severities

Abstract

Odontogenic ameloblast-associated protein (ODAM) reportedly plays an important role in maintaining periodontal integrity. We aimed to investigate the cause of different ODAM values in the gingival crevicular fluid (GCF) and discrepancies between GCF ODAM values and histological ODAM distribution in periodontal disease. ODAM concentration in the GCF of nine adult patients with severe periodontitis and ODAM distribution in the gingival tissues of three adult patients were analyzed using enzyme-linked immunosorbent assay and immunohistochemistry (IHC), respectively. ODAM in the GCF was detected in six samples but not in the remaining three samples; no differences were observed in the clinical characteristics between the ODAM-positive and ODAM-negative groups. ODAM was observed in the junctional epithelium of healthy gingival tissue by IHC analyses. There were two different ODAM expression patterns in gingival tissues with periodontitis of similar clinical severities, no overall expression or localized overexpression in the connective tissue layer. ODAM in severe periodontitis was secreted into the GCF or otherwise released into the connective tissue. Although clinically diagnosed as the same degree of periodontitis, the expression pattern of ODAM may differ according to whether ODAM can function as a junctional protein.