Francesco Burruano

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.

Maxillary bone necrosis following the use of formaldehyde containing paste: management and case series

Paraformaldehyde is used both as a disinfectant and to devitalise inflamed pulps when local anaesthesia is ineffective. Despite the clinical benefits, paraformaldehyde is not confined to the pulp, but penetrates the dentine and is gradually released as formaldehyde. This case series describes the effects on periodontal and bone tissues of paraformaldehyde used as a devitalising or disinfectant agent.

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.