H.C. Liu

Mandible reconstruction assisted by preoperative virtual surgical simulation.

OBJECTIVE In this study, we evaluated the clinical efficacy of mandible reconstruction with preoperative virtual planning, which focused on esthetics and occlusion. STUDY DESIGN A series of 9 patients were enrolled prospectively to undergo mandibulectomy and simultaneous reconstruction. Preoperative spiral CT scans of the maxillofacial region and the fibula region were performed. Virtual surgery of tumor resection and fibula reconstruction was performed in the Mimics platform. The reconstructed mandible models were fabricated with CAD/CAM technique. The reconstruction plate and the positioning template were accommodated to the stereolithographic model as the surgical template. RESULTS Surgery was performed accurately according to the templates. All the fibula flaps survived. The appearance and occlusion of the patients were satisfactory. CONCLUSIONS With preoperative virtual planning, the spatial relationship of the mandible and the fibula graft can be planned individually, which helps achieve optimum appearance and occlusion relationship.

Activation of Notch signaling in human tongue carcinoma

BACKGROUND Involvement of Notch signaling in several tumors is well known, but its role in tongue squamous cell carcinoma remains poorly characterized. The purpose of this study was to evaluate the roles of Notch signaling in the oncogenesis of tongue carcinoma. MATERIALS AND METHODS Tumor specimens and adjacent non-neoplastic tongue tissues from 74 patients with tongue carcinoma and human tongue carcinoma cell line Tca8113 were examined using immunohistochemistry and RT-PCR to determine the expressions of Notch1, Notch3, Jagged1, and Jagged2. RESULTS The mRNA expressions of Notch1, Notch3, Jagged1, and Jagged2 were detected in Tca8113, tongue carcinoma, and adjacent non-neoplastic tongue tissues. The expression levels of mRNAs in tongue carcinoma were higher than those in adjacent non-neoplastic tongue tissues (P < 0.05). Immunohistochemical examination showed that the Notch signal molecules were expressed in Tca8113, tongue carcinoma, and adjacent non-neoplastic tongue tissues. The expression rates of Notch1 and Notch3 protein in tongue carcinoma were higher than those in adjacent non-neoplastic tongue tissues (χ² = 6.10, P = 0.013; χ² = 3.94, P = 0.047). Notch1 and jagged1 were significantly more highly expressed in lymph node metastasis-positive tongue carcinoma (χ² = 6.108, P = 0.013; χ² = 7.354, P = 0.025). In addition, expressions of Notch3 and Jagged2 were highly correlated in tongue carcinoma tissues (χ² = 42.130, P < 0.001). CONCLUSIONS Expressions of Notch receptors and ligands in tongue carcinoma and adjacent non-neoplastic tongue tissues suggest that Notch signaling may control cell differentiation and proliferation of carcinoma cells. The disorder of Notch signaling may be a mechanism of the tongue carcinoma development.

Foxp3 expressed by tongue squamous cell carcinoma cells correlates with clinicopathologic features and overall survival in tongue squamous cell carcinoma patients

The forkhead transcription factor, Foxp3, has been identified as a key player in CD4(+)CD25(+)Foxp3(+) regulatory T cells (Tregs) function and a definitive marker of Tregs. Recently, it was reported that Foxp3 could be expressed by tumor cells themselves. The present study was to investigate the expression of Foxp3 in tongue squamous cells carcinoma (TSCC) cells and its clinical significance. In this study, the expression of Foxp3 by TSCC cells was demonstrated in TSCC tissue samples and three TSCC cell lines using immunohistochemical staining, realtime-PCR and Western blotting, and its clinical significance were statistically analyzed. The immunohistochemical assay in TSCC paraffin-embedded samples showed positive staining in 48 of 81 (59.3%) cases. The expression was significantly associated with pathologic differentiation (P=0.040) and T stage (P=0.000), and furthermore, inversely associate with patient survival (P=0.021). Multivariate analysis (Cox regression) suggested that Foxp3 expression in TSCC cells was an independent prognostic indicator for TSCC (P=0.032).

Mandible Reconstruction Assisted by Preoperative Simulation and Transferring Templates: Cadaveric Study of Accuracy

PURPOSE In this study we tried to define tumor resection, fibula cutting, and positioning by surgical templates to perform the mandible reconstruction surgery according to the preoperative simulation. The accuracy was evaluated through cadaveric surgery. MATERIALS AND METHODS Five cadaveric mandibles and fibulas were obtained. Preoperative surgical simulation was performed. Surgical templates that defined tumor resection, fibula cutting, and positioning were designed and fabricated. Translation, angular deviation, and rotation of bone grafts, as well as translation of condyles, were measured. RESULTS The reconstructed mandibles showed high similarity to the surgical planning. The mean translation, angular deviation, and rotation of fibula segments of the reconstructed mandibles were 1.35 ± 0.86 mm, 3.36° ± 1.86°, and 8.13° ± 5.35°, respectively. In the mandible remnants, the translation of condyles was measured, with a mean of 1.39 ± 0.66 mm. CONCLUSIONS Our method of defining the tumor resection, fibula cutting, and positioning by surgical templates was accurate enough for mandible reconstruction surgery.

High expression of the autophagy gene Beclin-1 is associated with favorable prognosis for salivary gland adenoid cystic carcinoma.

BACKGROUND Although autophagy is universally involved in tumorigenesis and tumor progression, the roles of autophagy and autophagy-regulating genes in salivary gland adenoid cystic carcinoma (ACC) remain unknown. In this study, we investigated the expression of the autophagy-regulating genes Beclin-1, death-associated protein kinase-1, ultraviolet radiation resistance-associated gene, and phosphatase and tensin homolog in salivary gland ACC samples. METHODS Immunohistochemistry and real-time polymerase chain reaction were used to analyze the expression of these genes in 89 ACC samples and normal salivary gland tissue samples. The relationship of their expression with clinicopathological features was analyzed. RESULTS The data showed significantly lower expression of these genes in the tumor samples than in normal salivary gland tissue samples. Furthermore, Beclin-1 expression was significantly correlated with histological pattern of ACC (P<0.05), and high expression of ultraviolet radiation resistance-associated gene was associated with distant metastasis (P<0.05). Most importantly, univariate and multivariate survival analyses suggested that Beclin-1 protein and mRNA expression in cancer cells were independent prognostic indicators for ACC. CONCLUSION Our results suggest that autophagy-regulating genes may participate in the pathogenesis of salivary gland ACC. Further research will be required to gain a better understanding of autophagy in ACC.

Mandibular Reconstruction Assisted by Preoperative Simulation and Accurate Transferring Templates: Preliminary Report of Clinical Application

PURPOSE This study investigated the application of a computer-aided design and manufacturing technique of defining tumor resection, fibula cutting, and positioning by surgical templates in mandibular reconstructive surgery. MATERIALS AND METHODS Four patients who required mandibulectomy and simultaneous reconstruction were enrolled in this study. Preoperative surgical simulation was performed. The surgical templates that defined tumor resection, fibula cutting, and positioning were designed and fabricated. RESULTS The surgeries were performed to the preoperative plan. All flaps survived. Superimposition of the postoperative image and the preoperative plan showed a satisfactory surgical accuracy. CONCLUSIONS This method of defining tumor resection, fibula cutting, and positioning by surgical templates was accurate enough for mandibular reconstructive surgery.

Sialoendoscopically Assisted Open Sialolithectomy for Removal of Large Submandibular Hilar Calculi

PURPOSE The management of large hilar calculi is a technically challenging issue during sialoendoscopic surgery. The aim of the present study was to evaluate the clinical efficacy of sialoendoscopically assisted open sialolithectomy for the removal of large submandibular hilar calculi to avoid sialoadenectomy. PATIENTS AND METHODS The present study was undertaken among patients with sialolithiasis scheduled for sialoendoscopic surgery from August 2005 to October 2008. When we failed to remove large submandibular hilar stones intraductally, we performed sialoendoscopically assisted open sialolithectomy. The clinical characteristics, pre- and intraoperative data, and outcomes were documented in a prospective fashion. RESULTS Of 78 consecutive patients with submandibular sialolithiasis, 18 were treated with sialoendoscopically assisted open sialolithectomy immediately after failure of intraductal removal of calculi by sialoendoscopy. For 17 patients, large hilar sialoliths were successfully removed using this surgical technique. The surgery failed in 1 patient with multiple sialoliths, and the procedure was converted to open sialoadenectomy. Temporary numbness of the tongue for 1 week postoperatively was documented in 3 patients. The patients were followed up for a median period of 18 months without any symptoms or signs of recurrence. CONCLUSION Our results suggest that sialoendoscopically assisted open sialolithectomy is an effective and safe surgical technique to remove large submandibular hilar calculi.

Detection of Notch signaling molecules in cemento‐ossifying fibroma of the jaws

BACKGROUND The aim of this study was to evaluate the roles of Notch signaling in the oncogenesis and cytodifferentiation of cemento-ossifying fibroma, the expressions of Notch receptors and ligands were detected in COF and normal jaw bones. MATERIALS AND METHODS The expressions of Notch1, Notch3, Jagged1, and Jagged2 were detected by reverse transcriptase polymerase chain reaction and immunohistochemistry respectively in 16 cases of normal bone tissues and 12 cases of COF of the jaws. RESULTS The mRNAs expressions of Notch1, Notch3, Jagged1, and Jagged2 were detected in all specimens. The expression levels of mRNAs in COF were higher than those in normal bones. In COF, Notch proteins staining were showed extensively distribution in fibroblasts and osteoblasts. In normal bone tissue, Notch proteins were expressed in osteoblasts, whereas proteins staining were weaker than those in COF, but no detection in fibroblast-like bone marrow stroma cells. The expressions of Notch receptors and ligands were not detected in cementum-like products or bone matrices. CONCLUSION Our data suggest that Notch signaling may participate in controlling cell differentiation and proliferation in normal bone and COF of the jaws. Notch signaling disorder may be a molecular incident in COF occurrence and development.

CT Virtual Sialendoscopy Versus Conventional Sialendoscopy in the Visualization of Salivary Ductal Lumen: An In Vitro Study

To evaluate the feasibility of computed tomographic (CT) virtual sialendoscopy and its performance characteristics for the visualization of salivary ductal lumen as compared with conventional sialendoscopy.

Suppression of tongue squamous cell carcinoma growth by inhibition of Jagged1 in vitro and in vivo

BACKGROUND The changes in Notch signaling are closely related to the occurrence and development of many cancers. We have investigated Notch signaling receptor and its ligand expressions in TSCC cell lines, tissues and its significance. We clarified Notch signaling pathway in TSCC and its mechanism. We regulated Notch signaling pathway of tumor cells, thereby inhibiting tumor cell proliferation and differentiation. METHODS We detected Jagged1 protein and mRNA expression levels in specimens (tongue cancer and adjacent tissues) from 74 patients with tongue cancer and in TSCC cell line. The Jagged1-targeted lentiviral vector RNAi system was constructed, and its suppressive effects on the proliferation and invasion of tongue carcinoma cells in in vivo and ex vivo were determined. RESULTS Jagged1 was expressed in tongue squamous cell cancer tissues and cell line, but there were differences in its expression. Jagged1 was knocked down and the tumor growth was inhibited accompanying cell cycle changes. Animal studies also showed that the tumor growth was inhibited. CONCLUSIONS Jagged1 may be involved in the differentiation and proliferation of tongue cancer. Targeting Jagged1 RNA interference lentiviral vector can effectively lower Jagged1 mRNA and protein expression levels of Tca8113 cells, thereby preventing the proliferation of TSCC cells. Jagged1 is expected to be a promising new target for curing tongue cancer. In-depth study of the interaction between Jagged1 and other molecules of Notch signaling pathway in the process of carcinogenesis has important theoretical guidance and clinical significance in revealing the mechanism of Jagged1 and its application in the therapy for tongue cancer.