Immunoglobulin-producing cells in human odontogenic cysts

Immunohistochemical staining of immunoglobulin-containing plasma cells was performed on odontogenic keratocysts, dental (periapical) and dentigerous cysts. IgG-containing plasma cells were the predominant species in all cyst types examined, with a much lower percentage of IgA- and few IgM-containing plasma cells. Statistically significant differences in the percentage contributions of IgG and IgA plasma cells were observed between the keratocyst and both the dental (periapical) and dentigerous cysts and for IgM between the keratocyst and dental (periapical) cyst. Intense extracellular staining was observed for IgG in all cyst types.

Some observations on the fluids of odontogenic cysts

The fluids of 44 dental cysts, 19 dentigerous cysts, 36 odontogenic keratocysts, and 12 ameloblastomas have been investigated. The incidence of epithelial cells, inflammatory cells, cholesterol crystals and bacteria was recorded in smears. There was a high incidence of epithelial cells in odontogenic keratocysts and not in other lesions. Cholesterol crystals had a similar incidence in all lesions. The proportion of the soluble proteins and total protein content was determined from cellulose acetate electrophoresis. Dental cysts contained an average of 51.19% albumin, 17.52% beta globulin, 22.04 % gamma globulin, and 6.30 g/100 ml protein. Dentigerous cysts contained an average of 61.35% albumin, 13.98% beta globulin, 12.70% gamma globulin and 5.40 g/100 ml protein. Odontogenic keratocysts contained an average of 78.03% albumin, 7.51% beta globulin, 7.91% gamma globulin, and 2.09 g/100 ml protein. Ameloblastomas contained an average of 67.38% albumin, 12.83% beta globulin, 12.60% gamma globulin and 4.86 g/100 ml protein. The immunoglobulin content was determined by single radial immunodiffusion. Dental cysts contained an average of 488.9 mg/100 ml IgA, 2535.4 mg/100 ml IgG, and 135.6 mg/100 ml IgM. Dentigerous cysts contained an average of 308.4 mg/100 ml IgA, 1618.2 mg/100 ml IgG, and 155.6 mg/100 ml IgM. Odontogenic keratocysts contained an average of 135.6 mg/100 ml IgA, 491.9 mg/100 ml IgG, and 54.1 mg/100 ml IgM. The significance of these findings in the pathogenesis and diagnosis of these lesions is discussed.

Scanning electron microscopy of cells from periapical lesions

Examination of lymphocytes from peripheral blood with the scanning electron microscope (SEM) has shown differences between B cells and T cells on the basis of their surface architecture. This study was initiated to determine whether the cellular components of periapical lesions could be identified with the use of similar criteria. Cells were dispersed from lesions by aspiration of fragments of tissue through syringe needles of decreasing diameters. The liberated cells were filtered on silver-coated Flotronic membranes and examined under the SEM. Lymphocytes, macrophages, epithelial cells, and mast cells were observed in granulomas and cysts. Most of the lymphocytes had smooth surfaces similar to that of T cells; others had villous projections similar to that of B cells. Epithelial nests were seen in the cyst linings while the cyst fluid was rich in lymphocytes. These findings suggest that SEM examination of periapical lesions can be a useful adjunct in studying cellular composition and possible immunological reactions in these tissues.

The pathogenesis of odontogenic cysts: a review

The pathogenesis of the three common forms of odontogenic cyst is discussed. It is concluded that the dental cyst arises from proliferation of the epithelial rests of Malassez in a focus of inflammation stimulated by pulpal necrosis of the associated tooth. It enlarges by unicentric expansion from the hydrostatis pressure of its contents. The dentigerous cyst arises from pooling of inflammatory exudate, which is derived from the obstructed follicular veins of an unerupted tooth and accumulates between the reduced enamel epithelium and the crown of the tooth. It enlarges by unicentric expansion from the hydrostatic pressure of its contents. The odontogenic keratocyst arises by proliferation of the residues of the dental lamina, possibly as a hamartomatous abnormality. It enlarges by both multicentric expansion due to the proliferation of localized groups of epithelial cells in the lining and by unicentric expansion from the hydrostatic pressure of its contents.