Confocal laser scanning microscopy of liesegang rings in odontogenic cysts: analysis of three-dimensional image reconstruction.

Liesegang rings are concentric noncellular lamellar structures, occasionally found in inflammatory tissues. They have been confused with various parasites, algas, calcification, and psammoma bodies. The authors examined Liesegang rings from oral inflammatory cysts by both optical and confocal laser scanning microscopy, and perfomed a three-dimensional reconstruction. These investigations indicate that Liesegang rings are composed of multiple birefringent concentric rings, resulting from a progressive deposition of organic substances, with an unclear pathogenesis.

Two cases of mandibular radicular cysts with ciliated epithelium: an electron microscopic study.

We studied two cases of mandibular radicular cysts lined in part with ciliated epithelium by examining them histopathologically and ultrastructurally. In addition, we examined the incidence of cilia in 205 radicular cysts in the biopsy materials collection in our Department. No other mandibular cysts having cilia in the lining were found, and so these were very rare. Regarding the histogenesis of the cilia, we consider that the development of cilia in mandibular radicular cysts may be due to true metaplasia rather than to adaptation which is a functional requisite of the lining epithelium for the unique cystic environment.

Scanning electron microscopic observations on the inner surface of jaw cysts.

The cavity surface of 9 jaw cysts was studied in the scanning electron microscope. The material comprised 5 radicular, 2 residual, 1 dentigerous and 1 globulomaxillary cyst. The surface morphology varied from smooth to ruffled within the same cyst, and between cysts. Interepithelial spaces, some of which contained migrating leukocytes, were frequently observed. Bacteria occurred in 1 cyst (dentigerous) only, and included rods, filaments and spirochetes. Crystals of various morphology were seen in 6 of the cysts.

Scanning electron microscopy of odontogenic cyst epithelium.

The epithelial lining of 8 odontogenic keratocysts (OKC), 9 radicular (RC) and 3 dentigerous cysts (DC) were examined in SEM in order to study the ultrastructural surface topography of the lumenal surface cells. The orthokeratinized OKC showed a reticular network of intercommunicating microridges surrounding micropits giving a honeycombed appearance to the entire surface. The deep surface of these cells was covered by a complementary array of short stubby microvilli. This pattern was identical to that described for oral epithelium in areas of masticatory mucosa. The parakeratinized OKC showed a complex pattern of microplications (MP) on both upper and deep cell surfaces. The non-keratinized linings of RC and DC revealed a similar MP pattern but of a less complex nature. The MP pattern of cells from para- and non-keratinized cysts was identical to that described for oral epithelial cells from lining mucosa. The surface ultrastructure of ciliated, mucus and brush cells occurring in RC was found to be indistinguishable from that described in the mammalian respiratory tract. The MP pattern forms part of the cellular interdigitation mechanisms in stratified squamous epithelium. Differences in the ultrastructural configuration are related to the type of epithelium in terms of keratinization rather than to protective functions.

Ultrastructure of odontogenic jaw cysts.

The epithelial ultrastructure of six radicular cysts, four follicular cysts, and five keratocysts was studied with special attention to the epithelium-connective tissue junction. Inflammation was found to cause widened interepithelial cell spaces which often harbored inflammatory cells in the radicular and follicular cysts. The characteristic structures at the epithelium-connective tissue junction (plasma membrane, lamina lucida and basal lamina) were not affected by inflammation. Fibrous structures were seen to connect the basal lamina to the underlining collagenous connective tissue. The keratocyst specimens, however, showed juxtaepithelial collagenolysis that was not associated with the degree of inflammation. Desmosomes were rare in the inflamed keratocysts' spinous layer but the cell-to-cell interactions still appeared close. Inflammatory cells were not detected within epithelium of the keratocyst specimens.

Light and ultrastructural studies of human chronic periapical lesions.

Forty clinically chronic periapical granulomas and cysts and their corresponding teeth were removed. Diagnosis was by light and transmission electron microscopy. Ultrastructural features of the root surfaces concerned and the corresponding soft tissue were detected by scanning electron microscopy. Chronic periapical inflammation had caused root resorption which affected the cementum and/or the dentin. There were no ultrastructural differences between granuloma- and cyst-induced root resorption. Resorption lacunae were devoid of epithelial and connective tissue attachment. However, root surface exposed to granulomas and cysts also indicated spontaneous cementum repair. Moreover, at their periphery, cellular debris, cells defined as fibroblasts, and cell projections and fibrils could be seen which were continuations of the periodontal ligament.

Estudo microscópico e imuno-histoquímico dos cistos periodontais apicais de dentes tratados ou näo endodonticamente: sua relaçäo com a regressäo näo cirúrgica / Microscopical and immunohistochemical study of the apical periodontal cysts of teeth treated or not endodontically: its relation with a not surgical regression

A resoluçäo näo cirúrgica dos cistos periodontais apicais ainda é questionável, principalmente porque sua comprovaçäo depende de resultados obtidos clínica e radiograficamente, näo fundamentados em observaçöes microscópicas. A partir de 348 casos registrados e organizados nos arquivos do Departamento de Patologia, da Faculdade de Odontologia de Bauru da Universidade de Säo Paulo, utilizando-se das técnicas de coloraçäo de rotina e de imuno-histoquímica, propusemo-nos: 1) a observar microscopicamente as alteraçöes morfológicas do revestimento epitelial, da parede conjuntiva e do lume dos cistos periodontais apicais de dentes tratados ou näo endodonticamente e dos cistos periodontais residuais, para estabelecer-se padröes morfológicos microscópicos próprios; 2) interrrelacionar os dados obtidos nos diversos grupos experimentais, a fim de implicar os aspectos microscópicos que possam sugerir uma regressäo näo cirúrgica dos cistos periodontais apicais de dentes tratados endodonticamente; 3) analisar as distribuiçöes das células B, das células T e das células de Langerhans nas estruturas dos cistos periodontais apicais de dentes tratados ou näo endodonticamente e dos cistos residuais, para estabelecer-se padröes próprios na distribuiçäo das células imunológicas, marcadas imuno-histoquimicamente, em cada grupo experimental já mencionados, e, correlacioná-los com os padröes microscópicos próprios, para aferir uma provável regressäo näo cirúrgica desta periapicopa...