Preservation and demonstration of mast cells in human apical granulomas and radicular cysts

abstract – The investigation concerns the preservation and demonstration of human mast cells in undemineralized material. The material comprised human apical granulomas and radicular cysts dissected from extracted teeth or obtained by apicoectomy and cyst removal. Chronically inflamed human gingiva, rat tongue, and rat peritoneum served as control tissues. The following fixations were tested: 4% formaldehyde solution buffered to pH 7.2, Newcomer's fluid, and a 4% aqueous solution of basic lead acetate with formalin 1:10 added. The following dyes and fluorochromes were tested: toluidine blue in various concentrations and at various pH values, Astra-blue, the esterase substrate naphthol-AS-D-chloroacetate in combination with GBC, acridine orange in various concentrations and at various pH values, berberine-sulfate, and thioflavin T. Abundant mast cells were demonstrated in all granulomas and cysts with at least one of the staining methods tested. A 4% lead acetate solution with formalin added proved the best fixative for the preservation of the human mast cells, whereas staining with Astra-blue appeared the superior technique for demonstrating the human mast cells. Acridine orange showed the best secondary fluorescence of the fluorochromes tested. The best results with this dye were obtained using a 0.03% solution in 5% AlSO₄.     

The incidence of epithelium in periapical granulomas and the mechanism of cavitation in apical dental cysts in man

In two series of periapical granulomas, approximately one third contained proliferating epithelium, the highest incidence being in the third and fourth decades. Histological observations on the walls of radicular cysts suggest that the cyst wall may result from a three-dimensional proliferation of epithelium. The hypotheses of the mechanism whereby apical cysts undergo central cavitation were investigated histochemically. Proteolytic enzyme activity was detected (a) in the connective tissue within and around the loops of epithelium, suggesting that cavitation may occur owing to connective tissue breakdown, followed by epithelial proliferation and (b) within the epithelium, suggesting that cavitation may be caused by intra-epithelial breakdown.     

Application of cross-sectional imaging in the differential diagnosis of apical radiolucency

A case is described in which exact localization of a cystic lesion associated with the apices of the maxillary central incisor teeth was sought to aid diagnosis and pre-surgical planning. The area was imaged using cross-sectional tomographic slices in the sagittal plane produced by a Scanora® multimodal tomographic unit (Orion Corporation Soredex, Helsinki, Finland). The images demonstrated the cystic lesion arising within the incisive canal, confirming a diagnosis of naso-palatine duct cyst. Surgery was therefore performed via a palatal approach giving direct access to the cyst. Histological examination of the enucleated cyst confirmed a naso-palatine duct cyst.     

Effect of demineralization on stainability of human mast cells in normal periodontal membranes, apical granulomas and radicular cysts

abstract — The material comprised normal human periodontal membranes, apical granulomas and radicular cysts attached to extracted teeth. Chronically inflamed human gingiva and different rat tissues served as controls. The following demineralizing agents were tested: 5.3% HNO₃, 2% formic acid +20% Na-citrate, 5% EDTA, 10% EDTA+7.5% PVP, 0.05 M EDTA+0.22 M sucrose. Fixation: 4% aqueous solution of basic lead acetate with formalin 1:10 added. The following staining procedures were applied: toluidine blue pH 4.0, astra blue pH 0.2–0.3, naphthol-esterase-GBC pH 7.4, and acridine orange in 5% ALSO₄, pH 3.4. Demineralization in HNO₃, formic acid+Na-citrate, and 5% EDTA proved unsatisfactory. EDTA+PVP showed valuable staining results, but no secondary fluorescence could be observed after 18 d of exposure to this fluid. The best results were obtained with EDTA+sucrose. Even after 120 d of exposure to this demineralizing agent the human mast cells could be readily demonstrated by all four staining techniques used. In addition, the human mast cells appeared morphologically well preserved.     

Radiographic features of periapical cysts and granulomas

Many studies have been reported on radiographic lesion sizes of periapical lesions. However no studies have been reported on prevalences of subjective radiographic features in these lesions except for the early assumption that a periapical cyst usually exhibit a radiopaque cortex. This study is conducted to evaluate the prevalences of several subjective radiographic features of periapical cysts and granulomas in the hope to identify features that maybe suggestive of either diagnosis. The results showed that a regular (circular or semi-circular) radiographic outline is likely to be a periapical cyst while an irregular radiographic outline is not indicative of either a cyst or a granuloma. The association between the regular/irregular radiographic outline and the type of periapical lesion was found to be statistically significant (p less than 0.001). The associations of two other radiographic features and the type of periapical lesion were found to be just statistically significant (p less than 0.01). These features are the symmetry/asymmetry of the radiolucency in relation to the apex and the funnel-shaped/angular-shaped extension of the radiolucency. The widely accepted criteria that the possession of a radiopaque cortex surrounding the radiolucency can discriminate between a periapical cyst and granuloma cannot be statistically supported in this study.     

The nature of epithelial proliferation in apical granulomas

Small sections of granulomas containing proliferating epithelium were incubated with a radio-opaque marker (Thorotrast®) and tissue culture medium. Electron microscopic examination demonstrated that some epithelial cells had the potential to take up the marker whereas in control sections of apical cysts this did not occur. The implications of these results are discussed.     

Heparanase expression in periapical granulomas and radicular cysts

Heparanase is an endo-β-d-glucuronidase enzyme which degrades heparan sulfate glycosaminoglycan side chains of proteoglycans in the extracellular matrix and in basement membranes. The aim of this study was to evaluate the expression of heparanase in periapical granulomas (PGs) and radicular cysts (RCs). Immunohistochemistry was used to assess heparanase expression in PGs and RCs. Parameters including stain intensity, location and cell type were used to characterize heparanase expression in the periapical lesions. Ordered categories (from weak to strong) were used to compare the level of heparanase staining in the PG and RC groups. Both epithelial cells and inflammatory cells were positive for heparanase. The relative staining of the epithelial cells was strong, whereas the relative staining of the inflammatory cells was weak. Significant differences in immunohistochemical staining of epithelial cells were observed between RCs and PGs (p = 0.002). The relative expression of heparanase in epithelial cells in RCs was strong. In PGs, lesions with few or no epithelial cells, heparanase was predominantly expressed weakly by inflammatory cells. PGs and RCs have the same infectious origin. Therefore, the different cellular sources of heparanase in these periapical lesions may imply that this enzyme has specific pathogenetic functions in RCs and PGs.     

CBCT 辅助诊断、治疗左下颌尖牙双根管根尖周炎1例

报道1例在CBCT辅助下诊断和治疗的左下颌尖牙双根管病例。CBCT能够三维显示根管的形态和分布,在术前术中对根管变异作出明确的诊断,对防止根管遗漏、保存牙本质和保障根管治疗成功有一定的临床指导意义。     

The relationship of lesion size to diagnosis,incidence, and treatment of periapical cysts and granulomas

The authors have reviewed the literature relevant to diagnosis, incidence, and treatment of periapical cysts and granulomas. They suggest that lesion size may have a significant influence in all those areas. On the basis of this viewpoint, they suggest alternatives to various commonly held assumptions and potential solutions to a number of controversial issues.     

Numerous recurrent trichilemmal cysts of the scalp: differential diagnosis and surgical management

Trichilemmal cysts are common benign soft tissue tumors that occur in hairy areas, especially the scalp, where they present themselves as solitary masses that could be easily treated by surgical excision followed by pathologic identification. It is unusual to find these benign masses in very large numbers in 1 scalp. In the current article, we describe a 43-year-old woman who presented with 51 scalp masses, some of which recurred after repetitive excisions somewhere else by different surgeons under local anesthesia. These masses involved only the scalp and spared all the face. The patient presented to our clinic for a radical solution to clear her scalp from the unaesthetic look and appearance that forbid her from exposing her head and for hygienic reasons relating to the foul smell of repeated previous recurrences and infections. Her clinical presentation is described, and the suggested differential diagnosis and management for such a patient is discussed.     

Histochemical studies on cholesterol formation in odontogenic cysts and granulomas

abstract — A histologic and histochemical study was made of 45 odontogenic periapical cysts and granulomas with cholesterol formation. The specimens were transported in Histocon® solution and sectioned by cold microtome. This technique permits the preservation of the lipids and rertains the enzyme activities in the cells. Cholesterol crystals seemed to be formed in disintegrating clots of red blood corpuscles in congested capillaries of the inflammatory areas. The pericytes of the vessel walls changed their enzyme activities, indicating increased lysosomal functions, and eventually formed giant cells with tissue degrading properties.     

Identification of common foreign material in postendodontic granulomas and cysts.

The present investigation was undertaken to identify commonly occurring foreign material in postendodontic periapical granulomas and cysts. 29 biopsies from such lesions with observed foreign material were routinely processed, stained with H&E, von Kossa and Calcofluor White and investigated by light, polarization and fluorescence microscopy. Applying back-scattered SEM images, the foreign material was subjected to energy dispersive X-ray analysis. 4 groups of foreign material were observed: 1. Black/brownish fragments and yellow/brown granules containing Au, Ag, Cu, Hg, Sn and Zn compatible with amalgam. 2. Fine black/brown/yellow granules compatible with endodontic sealer components revealing Ag, Ba, Bi, Cu, S, Ti and Zn. 3. Basophilic fragments compatible with Ca salts from Ca(OH), extruded periapically and containing Ca and P. 4. Elongated/rounded/oval/kidney-shaped, colourless to slightly basophilic, birefringent structures revealing C and O and with a slit-like central canal and a bright, pale-blue fluorescence specific for cellulose.     

Comparative immunohistochemical study of the presence of mast cells in apical granulomas and periapical cysts: possible role of mast cells in the course of human periapical lesions

Cells other than macrophages and lymphocytes have recently been shown capable of producing cytokines and mediators. Among these are mast cells, a cell population now recognized for its immunoregulatory properties. Little is known about the complex interactions between cells, cytokines, and other inflammatory elements in periapical lesions. The objective of this investigation was to determine the immunohistochemical pattern of expression of mast cells tryptase in periapical lesions based on study of 20 apical granulomas and 20 periapical cysts. Microscopic analysis revealed mast cells to be present in greater numbers in periapical cysts than in apical granulomas, and in cysts were more numerous in regions of active inflammation. Mast cells tended to be more common in the peripheral regions of both periapical lesions, and were often found in close proximity to lymphocytes. These findings lead us to propose a functional relationship between these two cell populations that may facilitate elicitation of an immune response contributory to the pathogenesis of periapical lesions.