Tongue reconstruction with the gracilis myocutaneous free flap.

We describe our experience in tongue reconstruction using the transverse gracilis myocutaneous (TMG) free flap after major demolitive surgery for advanced cancer. This technique was used in 10 patients: seven underwent total glossectomy and three partial glossectomy. In eight patients we performed motor reinnervation attempting to maintain muscular trophism and gain long-term volumetric stability. The follow-up period ranged from 6 to 28 months. The overall flap survival was 100%. Nine out of 10 patients resumed oral intake. Our preliminary experience shows that this flap is a good reconstructive option for total glossectomy patients, whereas it is less suited for reconstruction of hemiglossectomy defects. Functional and objective evaluation of the tongue reconstructed with TMG free flap requires further and standardized evaluation.

Sclerosing odontogenic carcinoma with benign fibro-osseous lesion of the mandible: an extremely rare case report.

A case of sclerosing odontogenic carcinoma (SOC) admixed with a benign fibro-osseous lesion (BFOL) is reported herein. A 67-year-old male had paresthesia in the mental region. Computed tomography detected an intragnathic mass that was focally expansile with disappearance of cortical bone, and contained admixed radiolucency and radio-opacity. Under the pathological diagnosis as benign fibro-osseous lesion, it was surgically removed by curettage. Microscopic analysis showed that a few parts of the resected materials contained dispersed thin cords and small nests of epithelial cells accompanied by fibrous stroma. Cellular atypia and mitotic figures were not evident. The diagnosis of BFOL with hyperplastic and metaplastic odontogenic epithelia was ultimately made. Eight months after the operation, the lesion recurred and segmental mandibulectomy was carried out. Histologically, the lesion was predominantly occupied by the fibro-osseous component with irregular-shaped foci of epithelial component. The epithelial component exhibited mostly thin cord or small nest patterns and showed definite perineural infiltration. Immunohistochemically, the epithelial cells were positive for p63, cytokeratin (CK) 6 and CK19, and focally positive for CK7 but negative for vimentin. MIB-1 positive nuclei were inconspicuous. To the best of our knowledge, this report is the first case of SOC with BFOL.

Evaluation of the sclerotherapeutic efficacy of ethanol, polidocanol, and OK-432 using an in vitro model.

BACKGROUND: Sclerosants are used to treat vascular malformations. Owing to variations in the flow, the injected concentrations and the duration of exposure of these sclerosants are altered. Therefore, the clinical effectiveness of sclerotherapy is variable. OBJECTIVE: The objective was to evaluate the differences in clinical response, usually observed among ethanol, polidocanol, and OK-432, using an in vitro sclerotherapy model. METHODS: Endothelial cells were cultured and exposed to different concentrations of the sclerosants for 5 seconds and the remaining viable cells were counted using a MTT assay kit. Dyes were used to visualize the morphologic changes. Precipitant formation in blood was also evaluated. Finally, the degree of ICAM-1 expression, after exposure to lower concentrations of these sclerosants, was studied using immunocytochemistry. RESULTS: Only ethanol causes precipitant formation and kills almost all cells from 30% concentration. Polidocanol begins to disrupt the cell membrane from 0.0125% onward. Only OK-432 induces ICAM-1 expression. CONCLUSION: Ethanol's strong precipitant-forming effect may induce thromboembolism, thus enhancing sclerosis. Polidocanol's endothelial cell-lysing effect was clearly documented. OK-432 may mediate its effect by inducing inflammatory response of the endothelium via ICAM-1 expression. This in vitro model may be useful in evaluating other sclerosants as well.

Two-year clinical comparison of a flowable-type nano-hybrid composite and a paste-type composite in posterior restoration.

AIM: The purpose of the present study was to compare the clinical efficacy between a flowable-type nano-hybrid composite and a paste-type composite for posterior restoration. METHODS: Of 62 posterior teeth in 33 patients (mean age: 34.1 years), 31 were filled with a paste-type composite (Heliomolar [HM] group), and another 31 with a flowable nano-hybrid composite (MI FIL [MI] group). Clinical efficacy was evaluated at 2 years after the restoration. RESULTS: There were no differences for retention, surface texture deterioration, anatomical form change, deterioration of marginal adaptation, and secondary caries, while a statistical difference was found for marginal discoloration, which was significantly greater in the HM group (P < 0.05). Furthermore, color matching in the MI group was superior to that in the HM group immediately after the restoration throughout the study period. CONCLUSIONS: The present 2-year clinical evaluation of different composites showed that the flowable nano-hybrid composite could be an effective esthetic material for posterior restoration.

Novel biological activity of ameloblastin in enamel matrix derivative.

OBJECTIVE: Enamel matrix derivative (EMD) is used clinically to promote periodontal tissue regeneration. However, the effects of EMD on gingival epithelial cells during regeneration of periodontal tissues are unclear. In this in vitro study, we purified ameloblastin from EMD and investigated its biological effects on epithelial cells. MATERIAL AND METHODS: Bioactive fractions were purified from EMD by reversed-phase high-performance liquid chromatography using hydrophobic support with a C18 column. The mouse gingival epithelial cell line GE-1 and human oral squamous cell carcinoma line SCC-25 were treated with purified EMD fraction, and cell survival was assessed with a WST-1 assay. To identify the proteins in bioactive fractions of EMD, we used proteome analysis with two-dimensional gel electrophoresis followed by identification with liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis. RESULTS: Purified fractions from EMD suppressed proliferation of GE-1 and SCC-25. LC-MS/MS revealed that ameloblastin in EMD is the component responsible for inhibiting epithelial cell proliferation. The inhibitory effect of ameloblastin on the proliferation of GE-1 and SCC-25 was confirmed using recombinant protein. CONCLUSION: The inhibitory effects of EMD on epithelial cell proliferation are caused by the biological activities of ameloblastin, which suggests that ameloblastin is involved in regulating epithelial downgrowth in periodontal tissues.

Inhibitory effects of ameloblastin on epithelial cell proliferation.

OBJECTIVE: Ameloblastin is an enamel matrix protein expressed in several tissues. Many potential mechanisms have been identified by which ameloblastin functions as an extracellular matrix protein. However, the biological effects of ameloblastin on gingival epithelial cells remain unclear. In the present study, we established a novel system to purify recombinant human ameloblastin and clarified its biological functions in epithelial cells in vitro. DESIGN: Recombinant human ameloblastin was isolated from COS-7 cells overexpressing HaloTag-fused human ameloblastin by the HaloTag system and then purified further by reverse-phase high-performance liquid chromatography. SCC-25 cells, derived from human oral squamous cell carcinoma, were treated with recombinant ameloblastin and then cell survival was assessed by a WST-1 assay. Cell cycle analysis was performed by flow cytometry. RESULTS: The novel purification system allowed effective recovery of the recombinant ameloblastin proteins at a high purity. Recombinant ameloblastin protein was found to suppress the proliferation of SCC-25 cells. Flow cytometric analysis showed that ameloblastin treatment induced cell cycle arrest G1 phase. CONCLUSIONS: We developed a procedure for production of highly purified recombinant human ameloblastin. Biological analyses suggest that ameloblastin induces cell cycle arrest in epithelial cells and regulates the progression of periodontitis.

Effects of heat stress and starvation on clonal odontoblast-like cells.

INTRODUCTION: Heat stress during restorative procedures, particularly under severe starvation conditions, can trigger damage to dental pulp. In the present study, we examined effects of heat stress on odontoblastic activity and inflammatory responses in an odontoblast-like cell line (KN-3) under serum-starved conditions. METHODS: Viability, nuclear structures, and inflammatory responses of KN-3 cells were examined in culture medium containing 10% or 1% serum after exposure to heat stress at 43°C for 45 minutes. Gene expression of extracellular matrices, alkaline phosphatase activity, and detection of extracellular calcium deposition in cells exposed to heat stress were also examined. RESULTS: Reduced viability and apoptosis were transiently induced in KN-3 cells during the initial phases after heat stress; thereafter, cells recovered their viability. The cytotoxic effects of heat stress were enhanced under serum-starved conditions. Heat stress also strongly up-regulated expression of heat shock protein 25 as well as transient expression of tumor necrosis factor-alpha, interleukin-6, and cyclooxygenase-2 in KN-3 cells. In contrast, expression of type-1 collagen, runt-related transcription factor 2, and dentin sialophosphoprotein were not inhibited by heat stress although starvation suppressed ALP activity and delayed progression of calcification. CONCLUSIONS: Odontoblast-like cells showed thermoresistance with transient inflammatory responses and without loss of calcification activity, and their thermoresistance and calcification activity were influenced by nutritional status.

Novel biological activity of ameloblastin in enamel matrix derivative

Objective Enamel matrix derivative (EMD) is used clinically to promote periodontal tissue regeneration. However, the effects of EMD on gingival epithelial cells during regeneration of periodontal tissues are unclear. In this in vitro study, we purified ameloblastin from EMD and investigated its biological effects on epithelial cells. Material and Methods Bioactive fractions were purified from EMD by reversed-phase high-performance liquid chromatography using hydrophobic support with a C18 column. The mouse gingival epithelial cell line GE-1 and human oral squamous cell carcinoma line SCC-25 were treated with purified EMD fraction, and cell survival was assessed with a WST-1 assay. To identify the proteins in bioactive fractions of EMD, we used proteome analysis with two-dimensional gel electrophoresis followed by identification with liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis. Results Purified fractions from EMD suppressed proliferation of GE-1 and SCC-25. LC-MS/MS revealed that ameloblastin in EMD is the component responsible for inhibiting epithelial cell proliferation. The inhibitory effect of ameloblastin on the proliferation of GE-1 and SCC-25 was confirmed using recombinant protein. Conclusion The inhibitory effects of EMD on epithelial cell proliferation are caused by the biological activities of ameloblastin, which suggests that ameloblastin is involved in regulating epithelial downgrowth in periodontal tissues. .