Prevalence and distribution of odontogenic cysts in Sicily: 1986-2005.

The objective of this study was to assess the prevalence of odontogenic cysts (OCs) in Sicily and evaluate their distribution during a 20-year period. A cross-sectional retrospective study was carried out in 1,310 cysts of the jaw diagnosed in 12,197 individuals, who consecutively attended the Odontostomatologic Clinic of Palermo from 1986 to 2005. 1,273 cysts were classified as odontogenic, whereas only 37 were non-odontogenic. In the former group, the most frequent lesions were radicular cysts (84.5%), followed by dentigerous OCs (11.4%). Inflammatory radicular cysts were observed more in male gender, younger age at diagnosis and anterior maxilla as site of presentation. Unlike dentigerous cysts, the frequency of radicular cysts decreased from 10.4% in 1986-1995 to about 8% in 1996-2005 (P < 0.0001). Inflammatory radicular cysts are the most represented group among OCs in our area with a higher prevalence than that reported in other countries. The decreasing epidemiologic trend with time could be attributed to the possible changes in individual oral health behavior.

Hemangiopericytoma of the oral cavity after a ten-year follow-up.

Hemangiopericytoma (HPC) is a mesenchymal tumour that may be benign, malignant, or occur in an intermediate form. We report an unusual case of hemangiopericytoma located in the buccal mucosal region. The histopathologic features showed increased cellularity, necrosis, hemorrhage, low proliferation index, and 4 or less mitotic figures per 10 high-power fields. Since this histological pattern suggests an intermediate form characterized by unpredictable clinical behavior, life-long follow-up is essential. In this patient no recurrences or distant metastases were evident at 10-yr follow-up.

Juvenile central ossifying fibroma of the mandible: a case report.

Central ossifying fibroma is a rare fibro-osseous neoplasm in young children. It is highly aggressive and has a strong tendency to recur. We describe an 11-year-old girl with juvenile central ossifying fibromas of the mandible that caused obstruction of tooth eruption of the lower left second premolar. Oral examination revealed the presence of the primary lower left second molar and a small bony hard swelling over the left side of the mandibular body. After a computed tomographic scan, an incisional biopsy was performed, and the lesion proved to be a juvenile ossifying fibroma. Although this tumor often recurs early, and many authors suggest radical en bloc resection, we performed a more conservative procedure to avoid damage to the mandibular nerve. There has been no evidence of recurrence 1 year later.

Expression of cyclooxygenase-1 and cyclooxygenase-2 in normal and pathological human oral mucosa.

Cyclooxigenase (COX) is the rate-limiting enzyme for the conversion of arachidonic acid (AA) to prostaglandins (PGs). Two isoforms of COX have been identified: COX-1 is constitutively expressed in many cells and is involved in cell homeostasis, angiogenesis and cell-cell signalling; COX-2 is not expressed in normal condition however it is strongly expressed in inflammation. The oral cavity is constantly exposed to physical and chemical trauma that could lead to mucosal reactions such as hyperplasia, dysplasia and cancer. Early diagnosis is the most important issue to address for a positive outcome of oral cancer; therefore it would be useful to identify molecular markers whose expression is associated with the various stages of oral cancer progression. Since COX enzyme has been involved, with different mechanisms, in the development and progression of malignancies we decided to investigate the expression and localization of COX-1 and COX-2 in normal human oral mucosa and three different pathologies (hyperplasia, dysplasia and carcinoma) by immunohistochemistry and RT-PCR. COX-1 mRNA and protein have been detected already in normal oral mucosa and their expression progressively increases from normal samples towards hyperplasia, dysplasia and finally carcinoma. On the contrary, COX-2 is not expressed in the normal tissue, starts to be expressed in hyperplasia, reaches the maximum activation in dysplasia and then starts to be downregulated in carcinoma.