Calcifying odontogenic cysts associated with odontomas: confocal laser scanning microscopy analysis of 13 cases.

The so-called calcifying odontogenic cyst (COC) represents a heterogeneous group of lesions that exhibit a variety of clinico-pathologic features. It is an uncommon lesion and represents less than 2% of all odontogenic cysts and tumors. Recently, these lesions have been reclassified as calcifying cystic odontogenic tumors (CCOT), according to the new World Health Organization (WHO) classification. CCOT are frequently found in association with, or containing areas histologically identical to, various types of odontogenic tumors, such as complex/compound odontomas. This work analyzed clinical and histological data deriving from 13 patients affected by CCOT associated with odontomas. Moreover, a confocal laser scanning microscope (CLSM) analysis was undertaken to further a better understanding of the nature of this peculiar lesion.

Osteonecrosis of the jaw correlated to bisphosphonate therapy in non-oncologic patients: clinicopathological features of 24 patients.

OBJECTIVE: Osteonecrosis of the jaws (ONJ) is a well known side effect of bisphosphonate therapies in patients with multiple myeloma or other malignancies. Its real incidence is still undetermined, and only few cases of ONJ in patients taking bisphosphonates for non-oncologic diseases have been reported. It was postulated that the clinical features, predisposing factors, and treatment outcome of this subset of patients might be different from those of oncologic patients. METHODS: Over a 4 year period, a total of 102 bisphosphonate-treated patients affected by ONJ were identified. Among these, 24 patients underwent bisphosphonate therapy for non-neoplastic disease and their profile was analyzed. RESULTS: In this study cohort, bisphosphonates had been administered mainly for postmenopausal osteoporosis (20/24 patients, 83.3%), the duration of therapy until presentation of ONJ ranging from 11 to 40 months and the most common triggering event being dentoalveolar surgery. All patients were nonsmokers; 6 manifested multiple ONJ lesions and only 3 of them had possible comorbidities. Surgical debridement was performed in 19 patients for a total of 22 lesions, which were individually considered in the followup. The latter showed complete remission of ONJ in 21/22 lesions. CONCLUSION: Although it might be considered a rare condition in non-oncologic patients, ONJ is a harmful side effect of bisphosphonate therapies. Clinicians must be aware of this entity, inform patients of the risks related to dental surgery, and possibly undertake adequate preventive measures.

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.

New approach for static bone histomorphometry: confocal laser scanning microscopy of maxillo-facial normal bone.

To define the value of confocal laser scanning microscopy (CLSM) as a practical method for a qualitative and quantitative analysis of hard tissue, the authors have analyzed normal maxillo-facial bone. They obtained and analyzed 58 bone samples from 28 patients who underwent to implant surgery. All the samples presented intense autofluorescence primarily ascribed to collagen. Variable degrees of autofluorescence have been identified between osteones and interosteonic bone. CLSM allowed improved tissue imaging, bidimensional pictures with better resolution at cellular level, and, in particular, the possibility of different histomorphometric evaluation. The application of CLSM to bone histomorphometry represents a new and never described technique, which might produce many insights in the study of normal and pathological bone.

Unusual case of adverse reaction in the use of sodium hypochlorite during endodontic treatment: a case report.

Sodium hypochlorite (NaOCl) is currently used in the debridement and disinfection of the root canal system, supporting the mechanical procedures. Although it is considered a safe irrigant, the literature reports a few cases of adverse reaction caused by NaOCl: They range from injection through the apical foramen to air emphysema and allergic reactions as complications during endodontic treatment. The present report shows the possible severe clinical consequences of concentrated NaOCl extruding through the periapical tissues during root canal irrigation in a patient not allergic to NaOCl.

Analysis of collagen distribution in human crown dentin by confocal laser scanning microscopy.

The authors used confocal laser scanning microscope to analyze human crown dentin. Specimens from 10 teeth were divided in two groups, one of which was decalcified and stained with hematoxylin and eosin. In the second group an undecalcified section was analyzed. Both groups were scanned by confocal microscope to generate optically sectioned images. All of the analyzed samples presented an intense autofluorescent that was ascribed to collagens. The degree of autofluorescence intensity was variable and might be due to collagen expression. The results indicate that a confocal microscope may be of help in analyzing and defining the nature and extent of collagen fibrils in human dentin.

Confocal laser scanning microscopy of human cementocytes: analysis of three-dimensional image reconstruction.

In order to define a practical method for a quantitative-qualitative analysis of dental hard tissue cells, we have studied cementocytes of human teeth using Confocal Laser Scanning Microscopy (CLSM), a research technique based on laser light microscopic analysis of biological samples stained for fluorescence observation. One thousand and eight hundred cementocyte images were analyzed. CLSM allowed improved tissue imaging, bi-dimensional pictures with better resolution at cellular level and, in particular, the possibility of a three-dimensional image reconstruction, thus providing a dynamic view of the cell under different situations. CLSM allowed a careful morphological observation and dimensional analysis of cementocytes at cellular resolution: cementocyte dimensional parameters like cell body without cell processes, cell dimensions with cell processes, and the number of cellular processes could be obtained. In conclusion, this study reports the fine definition of cementocytes at microscopic level by CSLM and the results warrant the use of this technique for further comparative analyses between normal and pathological cementocyte cells, e.g. cementum neoplasia and periodontal disease which still await a clear analytical description at cellular level.

Analysis of ghost cells in calcifying cystic odontogenic tumors by confocal laser scanning microscopy.

OBJECTIVE: The confocal laser scanning microscope represents an effective tool for studying biological samples stained for fluorescence observation. In this study we have used the confocal microscope to analyze ghost cells in calcifying cystic odontogenic tumors. STUDY DESIGN: Specimens from 15 calcifying cystic odontogenic tumor cases were stained with hematoxylin and eosin, and scanned by a confocal laser scanning microscope to generate optically sectioned images. RESULTS: All of the analyzed samples presented autofluorescent cells that were identified as ghost cells. The degree of autofluorescence intensity was variable and may be a result of the presence of hard keratin. CONCLUSION: The confocal laser scanning microscope may be of help in analyzing and defining the nature and extent of keratinization processes in calcifying cystic odontogenic tumor ghost cells.