Comparative study of the anaesthetic efficacy of 4% articaine versus 2% mepivacaine in mandibular third molar germectomy using different anaesthetic techniques: a split-mouth clinical trial.

BACKGROUND: Currently, one of the most discouraging aspects for many patients undergoing dental procedures is the administration of local anaesthesia. Therefore, there is a constant search for new techniques to avoid the invasive and painful nature of the injection. This study aimed to compare the clinical efficacy of local anaesthetics with articaine 4% or mepivacaine 2% (both with epinephrine 1:100.000), using different anaesthetic techniques to perform germectomy of lower third molars and to assess patients' feelings and pain during surgery. METHODS: Totally 50 patients (ranged 11-16 years) who required germectomy of mandibular third molars were recruited. Each patient received local anaesthesia on one side with articaine inoculated with plexus technique while on the other side with mepivacaine using inferior alveolar nerve block technique. The patients' evaluation was performed on pre and intraoperative tactile-pressure feelings and intraoperative pain with four levels on the Visual Analogue Scale (VAS). RESULTS: Surgical operations lasted less with more efficient analgesia when articaine was used. The additional intraosseous injection was required mainly in the mepivacaine group intraoperatively. A few patients had tactile-pressure feelings while intraoperative pain sensation was absent in 90% of cases with articaine. Significant differences were found in the cases who reported "absent" and "moderate" VAS values, favoring the use of articaine. CONCLUSIONS: Articaine injected with a plexus anaesthetic technique seems to be more clinically manageable than mepivacaine for the mandibular third molar germectomy. The discomfort of tactile-pressure feelings and pain experienced was lower using articaine anaesthetic technique used.

Cellular neurothekeoma with neuroendocrine differentiation.

We report a case of cellular neurothekeoma with unusual clinicopathological features in which neuroendocrine markers, determined by immunohistochemistry were observed. Histologically, the tumor showed a micronodular architecture with hypercellular lobules composed of slightly spindled to epithelioid cells, with nuclear atypia or pleomorphism and extension into fat, skeletal muscle. Neoplastic cells were immunoreactive for NKI/C3, CD68, CD10, and smooth-muscle actin, whereas S100 and HMB-45 staining was negative. An intriguing feature was the strong expression by tumor cells of different neuroendocrine markers. Clinical follow up showed no local recurrences after five months despite the presence of positive margins. The presence of atypical histopathological features may cause diagnostic problems with malignant mesenchymal tumors, nevo-melanocytic lesions, and fibrohistiocytic tumors. The immunohistochemical profile including the positive staining for neuroendocrine markers may suggest divergent differentiation or an origin from myofibroblast and neuroendocrine cells.

Epithelioid variant of pleomorphic liposarcoma as potential mimic of metastatic carcinoma.

We report a case of epithelioid variant of pleomorphic liposarcoma (EPL) found in the the infrapatellar fat pad of Hoffa of a 31-year old male. Histologically, the predominant population was formed by epithelioid cells with eosinophilic or clear cytoplasm admixed with rare pleomorphic lipoblasts. The immunohistochemical panel was not helpful in the diagnosis. FISH analysis using the locus-specific indicator CHOP (12q13) dual color break apart was applied to representative formalin-fixed, paraffin-embedded tissue sections. The result of FISH indicated a rearranged CHOP (DDIT3) gene and confirmed the diagnosis of EPL. The EPL should be differentiated from a metastatic carcinoma or other type of sarcoma. In these cases a clinicopathological correlation and an exhaustive sampling of the specimen for demonstration of lipogenic areas or pleomorphic lipoblasts is always necessary. FISH with demonstration of CHOP gene rearrangement is useful in providing specific ancillary information for the difficult differential diagnosis of this case.