Different manifestations of calcifying cystic odontogenic tumor.

The calcifying cystic odontogenic tumor normally presents as a painless, slow-growing mass, involving both maxilla and mandible, primarily the anterior segment (incisor/canine area). It generally affects young adults in the third to fourth decades, with no gender predilection. Computerized tomography images revealed important characteristics that were not detected by panoramic radiography, such as fenestration, calcification and tooth-like structures. The typical microscopic feature of this lesion is the presence of variable amounts of aberrant epithelial cells, without nuclei, which are named "ghost cells". In addition, dysplastic dentine can be found and occasionally the cyst can be associated with an area of dental hard tissue formation resembling an odontoma. The treatment for calcifying cystic odontogenic tumor involves simple enucleation and curettage. The purpose of this article is to present two different manifestation of calcifying cystic odontogenic tumor in which computerized tomography, associated to clinical features, served as an important tool for diagnosis, adequate surgical planning and follow-up of patients.

Action of nitric oxide on healthy and inflamed human dental pulp tissue.

Irreversible pulpitis has been associated with pain and an increase in the number of pulp inflammatory cells. Based on the action of nitric oxide (NO) elsewhere, NO may possibly participate in the sensory and autonomic innervation of the dental pulp, and may influence local inflammatory responses. The purpose of this study was to analyze normal and inflamed human dental pulp for the presence of NADPH-diaphorase (NADPH-d), as an index of NO system activity. Six non-carious second premolar pulp tissue samples were obtained from young patients who required extractions for orthodontic reasons and six inflamed samples were obtained from symptomatic carious second premolars clinically diagnosed with irreversible pulpitis. Pulp tissue was carefully removed, fixed by immersion in a cold 4% PFA buffered solution for 120 min, rinsed in cold phosphate buffer, and quickly-frozen for cryostat sectioning. Pulp tissue was sectioned perpendicularly to the vertical axis of the tooth at 20 microm and processed for histochemistry. Sections of each specimen were stained with hematoxylin-eosin and other sections were subjected to histochemical NADPH-d detection. Results indicated the presence of NADPH reactivity within the pulps of both normal and carious teeth. In the normal teeth NADPH-d activity was detected in a small number of vascular endothelial cells and fibroblasts. The inflammatory response of the pulp from carious premolars was detected in connective tissue by the presence of an increased number of fibroblasts, angioblasts and collagen fibers. It was possible to determine the extent of odontoblast reactivity since the odontoblast layer was usually absent in these split-peel preparations. There were no obvious signs of stained pulpal nerve fibers. Overall NADPH-d staining was significantly more intense within inflamed pulp tissues compared to normal healthy samples (Mann-Whitney test, p<0.002). These results suggest that NADPH-d may be used as a marker of inflammatory activity in pulpitis and provide the basis for further studies aiming to clarify the possible functions of NO in human dental pulp in pathophysiological situations.