Immunohistochemical analysis of matrix metalloproteinases (1, 2, and 9), Ki-67, and myofibroblasts in keratocystic odontogenic tumors and pericoronal follicles.

BACKGROUND: Keratocystic odontogenic tumor (KCOT) is a benign tumor that arises sporadically or associated with nevoid basal cell carcinoma syndrome (NBCCS). Its locally aggressive behavior contrasts with its cystic histological appearance. To better understand the interaction between tumor cells and the stroma, the present study aimed to evaluate and compare the immunohistochemical expression of matrix metalloproteinases (MMP-1, -2, and -9), the cellular proliferation index (Ki-67), and the presence of myofibroblasts (MFs) in KCOTs. METHODS: Eleven cases of isolated KCOT (G1) and 12 cases of KCOT associated with NBCCS (G2) were selected for an immunohistochemical investigation of the proteins MMP-1, MMP-2, MMP-9, Ki-67, and α-smooth muscle actin (α-SMA) in MFs. A group of 6 pericoronal follicles (G3) was included as a normal odontogenic tissue control. RESULTS: Significant differences between the G3 and G1/G2 groups regarding the expression of MMP-1, MMP-9 (in connective tissue), and Ki-67 were observed. In KCOT, there was a positive correlation between the Ki-67 antigen and MMP-1 and between MFs and MMP-1 in the parenchyma. No statistical differences were found between G1 and G2 groups. CONCLUSIONS: MMP-1, MMP-9, and proliferative activity appear to play important roles in KCOT pathogenesis. The increased proliferative activity with KCOT was associated with elevated MMP-1 production in the parenchyma, which influenced the growth of the lesion in association with an increased number of MFs.

Mouthwash with Active Oxygen (blue®m) Reduces Postoperative Inflammation and Pain.

The aim of this case series was to evaluate the effects of blue®m mouthwash on oral surgical wounds. Eleven patients underwent bilateral preprosthetic surgery and were instructed to apply the product only to the right side of the surgery. In this way, the right side corresponds to the test side and the left side (place without applying any type of solution) to the control side. After seven days of using the product (3 times a day), the following parameters were evaluated by means of a visual analogue scale: pain, changes in taste, and acceptance by the patient. Then, the level of tissue inflammation was assessed, by the number of pixels, using ImageJ® software. The main results show that the blue®m mouthwash was widely accepted by patients, reducing their pain. The number of inflammation pixels was lower on the test side (p < 0.05), indicating improved healing. It is suggested that blue®m mouthwash positively influences tissue healing reducing pain and the postsurgical inflammatory process; however, randomized clinical trials should be done to prove this clinical observation.

Utility of cell block in the cytological preoperative diagnosis of keratocystic odontogenic tumor.

In most cases involving jaw lesions, a biopsy and a histopathological analysis are necessary to establish the final diagnosis. However, biopsy may be a complex procedure at some maxillomandibular sites, and some systemic conditions could contraindicate the procedure. Thus, a search for new, less invasive techniques, which could eventually replace biopsy and simplify the diagnostic process, would benefit both professionals and patients. The aim of this study was to evaluate the cell block technique, prepared from the aspiration of luminal contents, in the preoperative diagnosis of keratocystic odontogenic tumors (KCOT). From 135 cases of lesions aspirated and processed by the cell block technique, we selected those containing keratin. In all cases selected, histological diagnosis was based on surgical biopsy. From 20 cases containing keratin in the cytological analyses, 19 were KCOTs and one was an orthokeratinized odontogenic cyst (OOC). In all KCOT cases, we observed the presence of parakeratin, even in those with intense inflammation. In the cytological analysis of the OOC, parakeratin was not observed. In conclusion, there is strong evidence that KCOT can be confidently diagnosed preoperatively by cytological analyses of lesions punctured and processed by the cell block technique.

Techniques for precancerous lesion diagnosis.

The development of the oral squamous cell carcinoma (OSCC) is a multistep process that requires the accumulation of multiple genetic alterations usually preceded by detectable mucosal changes, most often leukoplakias and erythroplakias. The clinical appearance of oral precancerous lesions and their degree of epithelium dysplasia suggests the malignization potential. Several techniques have been developed to improve the clinical and cytological diagnosis of oral precancerous lesions. The present paper reviews the main techniques used to improve premalignant lesion diagnosis.