Guang-sen Zheng

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.

Salivary gland functional recovery after sialendoscopy

To date, there has been no report on the salivary gland functional outcomes after sialendoscopic surgery. The purpose of this study is to evaluate salivary gland functional recovery after sialendoscopic management of obstructive salivary gland disease.

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.

Increased calcium and decreased magnesium and citrate concentrations of submandibular/sublingual saliva in sialolithiasis

OBJECTIVE The purpose of the present study was to investigate the electrolyte alterations of submandibular/sublingual saliva in submandibular sialolithiasis patients compared with saliva from healthy controls. DESIGN Submandibular/sublingual saliva was collected from 10 submandibular sialolithiasis patients and from 10 sex- and age-matched healthy controls. Ion chromatography was performed to determine the concentrations of inorganic cations (potassium, calcium, magnesium, and sodium), inorganic anions (chloride, phosphate, nitrate, and sulphate) and organic anions (thiocyanate, lactate, acetate, and citrate). RESULTS The calcium concentration was significantly higher in sialolithiasis patients than in controls (P<0.05). In contrast, the levels of magnesium and citrate in the saliva of sialolithiasis patients were significantly reduced compared to the values obtained in controls (P<0.05). No significant differences were detected among other ions. CONCLUSIONS Our findings indicate that saliva electrolyte composition of sialolithiasis patients is substantially altered with respect to crystallisation mechanisms. Increased calcium ion as a crystallisation substance and decreased magnesium and citrate ions as crystallisation inhibitors may be involved in the etiopathology of calculi formation.

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.

Digital Subtraction Angiography-Guided Percutaneous Sclerotherapy of Venous Malformations With Pingyangmycin and/or Absolute Ethanol in the Maxillofacial Region

PURPOSE The present study evaluated the safety and efficacy of digital subtraction angiography-guided percutaneous sclerotherapy of venous malformations (VMs) with pingyangmycin and/or absolute ethanol in the maxillofacial region. We present our safe and novel method for treating venous malformations. PATIENTS AND METHODS A total of 20 patients (21 locations) diagnosed with VMs were enrolled in the present trial. Evaluated by preoperative digital subtraction angiography, the lesions were categorized into 4 types according to the venous drainage features. Of the 20 patients, 5 had type I VMs, 5 had type II, 6 had type III and 3 had type IV VMs. One patient had type I and type III VMs in different locations of the maxillofacial region. For types I and II lesions, pingyangmycin sclerotherapy was performed. Multistage sclerotherapy with absolute ethanol and pingyangmycin was performed on types III and IV lesions. RESULTS After evaluation and guided by preoperative digital subtraction angiography, all the patients were treated successfully and safely. Of the 20 patients, the clinical outcome was excellent in 13, good in 6, and fair in 1. No disease recurrence was noted during the follow-up evaluations (range 6 to 25 months, median 13.55). The complications were fever in 5 patients after the first session of sclerotherapy, incomplete facial paralysis in 1, swelling in 1, and ulceration in 3. No major complications were observed. CONCLUSIONS Digital subtraction angiography-guided phlebography of VMs in the maxillofacial region is one of the approaches to classify VMs using anatomic and hemodynamic features. A strong association was seen between the type of VM and the approach of sclerotherapy. Percutaneous sclerotherapy using pingyangmycin and/or absolute ethanol is a safe and effective method of treating symptomatic VMs.

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.

Sialoliths or phleboliths

Salivary gland obstruction caused by vascular malformation with phleboliths is relatively uncommon and may be masquerading as sialolithiasis. This article presents the case of a patient who suffered from vascular malformation with phleboliths that caused submandibular gland obstruction and was once misdiagnosed as sialolithiasis.