OBJECTIVE To investigate the feasibility of employing a modified midfacial degloving in maxillectomy. METHODS Eight patients with carcinoma of the maxillary sinus underwent a modified midfacial degloving operation. Th...OBJECTIVE To investigate the feasibility of employing a modified midfacial degloving in maxillectomy. METHODS Eight patients with carcinoma of the maxillary sinus underwent a modified midfacial degloving operation. The tumors were classified according to the 2002 AJCC system. The TNM staging of the cases was as follows： 1 T4aN0M0, 2 T3N0M0 and 5 T2N0M0. Of the 8 cases, 1 patient underwent extended maxillectomy; exenteration of the orbit; tumorectomy of the sphenomaxillary and infratemporal fossae. Two patients received a total maxillectomy, and 5 a partial resection of the maxilla. Postoperative pathological report： 4 well-differentiated squamous carcinoma, 2 moderately-differentiated squamous carcinoma, 1 mucoepidermoid carcinoma and 1 adenoid cystic carcinoma.RESULTS A modified midfacial degloving operation can sufficiently expose a field of operation, resect the tumor within a safe margin, and leave no facial cicatricles. One patient died of intracranial metastasis 8 months after operation. We observed no recurrences or metastasis in other patients during the period of follow-up.CONCLUSION The major advantages of employing the modified midfacial degloving in maxillectomy is that a facial incision can be avoided. It has an advantage of minimal invasive surgery展开更多
Objective： To investigate the stress distribution to the mandible, with and without impacted third molars（IM3 s） at various orientations, resulting from a 2000-Newton impact force either from the anterior midline o...Objective： To investigate the stress distribution to the mandible, with and without impacted third molars（IM3 s） at various orientations, resulting from a 2000-Newton impact force either from the anterior midline or from the body of the mandible. Materials and methods： A 3 D mandibular virtual model from a healthy dentate patient was created and the mechanical properties of the mandible were categorized to 9 levels based on the Hounsfield unit measured from computed tomography（CT） images. Von Mises stress distributions to the mandibular angle and condylar areas from static impact forces（Load I-front blow and Load II left blow） were evaluated using finite element analysis（FEA）. Six groups with IM3 were included： full horizontal bony, full vertical bony, full 450 mesioangular bony, partial horizontal bony, partial vertical, and partial 450 mesioangular bony impaction, and a baseline group with no third molars. Results： Von Mises stresses in the condyle and angle areas were higher for partially than for fully impacted third molars under both loading conditions, with partial horizontal IM3 showing the highest fracture risk. Stresses were higher on the contralateral than on the ipsilateral side. Under Load II, the angle area had the highest stress for various orientations of IM3 s. The condylar region had the highest stress when IM3 s were absent. Conclusions： High-impact forces are more likely to cause condylar rather than angular fracture when IM3 s are missing. The risk of mandibular fracture is higher for partially than fully impacted third molars, with the angulation of impaction having little effect on facture risk.展开更多
Objective ：To investigate the feasibility of using natural poritos as scaffolds in bone tissue engineering （TE） and repair of caprine mandibular segmental defect with titanium reticulum reinforced. Methods： Natur...Objective ：To investigate the feasibility of using natural poritos as scaffolds in bone tissue engineering （TE） and repair of caprine mandibular segmental defect with titanium reticulum reinforced. Methods： Natural poritos with a pore of 190-230 μm in size and porosity of about 50 %-65 % was molded into the shape of granules 5 mm × 5 mm × 5 mm in size. Expanded autologous caprine marrow mesenchymal stem cells were induced by recombinant human morphogenetic protein-2 （rhBMP2） to improve osteoblastic phenotype. Then marrow derived osteoblasts were seeded into poritos in density of 4 × 10^7/ml and incubated in vitro for 48 hours prior to implantation. Then osteoblastic cells/poritos complexes were implanted into mandibular defect and the defect was reinforced by titanium reticulum. Implantation of poritos alone acted as the control. Bone regeneration was assessed 4, 8, 16 weeks after implantation using roentgenographie analysis and histological observation was done after 16 weeks. Results： New bone could be observed histologically on the surface and in the pores of natural coral in all specimens in the cell-seeding group, whereas in the control group there was no evidence of osteogenesis process in the center of the construction. The results showed that new bone grafts were successfully restored 16 weeks after implantation. Conclusions： This study suggests the feasibility of using porous coral as scaffold material transplanted with marrow derived osteoblasts by TE method. By means of titanium reticulum reinforcement, mandibular defect could be successfully restored. It shows the potentiality of using this method for the reconstruction of bone defect in cfinic.展开更多
文摘OBJECTIVE To investigate the feasibility of employing a modified midfacial degloving in maxillectomy. METHODS Eight patients with carcinoma of the maxillary sinus underwent a modified midfacial degloving operation. The tumors were classified according to the 2002 AJCC system. The TNM staging of the cases was as follows： 1 T4aN0M0, 2 T3N0M0 and 5 T2N0M0. Of the 8 cases, 1 patient underwent extended maxillectomy; exenteration of the orbit; tumorectomy of the sphenomaxillary and infratemporal fossae. Two patients received a total maxillectomy, and 5 a partial resection of the maxilla. Postoperative pathological report： 4 well-differentiated squamous carcinoma, 2 moderately-differentiated squamous carcinoma, 1 mucoepidermoid carcinoma and 1 adenoid cystic carcinoma.RESULTS A modified midfacial degloving operation can sufficiently expose a field of operation, resect the tumor within a safe margin, and leave no facial cicatricles. One patient died of intracranial metastasis 8 months after operation. We observed no recurrences or metastasis in other patients during the period of follow-up.CONCLUSION The major advantages of employing the modified midfacial degloving in maxillectomy is that a facial incision can be avoided. It has an advantage of minimal invasive surgery
基金Project supported by the National Natural Science Foundation of China(Nos.51375453 and 51775506)the Natural Science Foundation of Zhejiang Province(No.LY18E050022),China
文摘Objective： To investigate the stress distribution to the mandible, with and without impacted third molars（IM3 s） at various orientations, resulting from a 2000-Newton impact force either from the anterior midline or from the body of the mandible. Materials and methods： A 3 D mandibular virtual model from a healthy dentate patient was created and the mechanical properties of the mandible were categorized to 9 levels based on the Hounsfield unit measured from computed tomography（CT） images. Von Mises stress distributions to the mandibular angle and condylar areas from static impact forces（Load I-front blow and Load II left blow） were evaluated using finite element analysis（FEA）. Six groups with IM3 were included： full horizontal bony, full vertical bony, full 450 mesioangular bony, partial horizontal bony, partial vertical, and partial 450 mesioangular bony impaction, and a baseline group with no third molars. Results： Von Mises stresses in the condyle and angle areas were higher for partially than for fully impacted third molars under both loading conditions, with partial horizontal IM3 showing the highest fracture risk. Stresses were higher on the contralateral than on the ipsilateral side. Under Load II, the angle area had the highest stress for various orientations of IM3 s. The condylar region had the highest stress when IM3 s were absent. Conclusions： High-impact forces are more likely to cause condylar rather than angular fracture when IM3 s are missing. The risk of mandibular fracture is higher for partially than fully impacted third molars, with the angulation of impaction having little effect on facture risk.
文摘Objective ：To investigate the feasibility of using natural poritos as scaffolds in bone tissue engineering （TE） and repair of caprine mandibular segmental defect with titanium reticulum reinforced. Methods： Natural poritos with a pore of 190-230 μm in size and porosity of about 50 %-65 % was molded into the shape of granules 5 mm × 5 mm × 5 mm in size. Expanded autologous caprine marrow mesenchymal stem cells were induced by recombinant human morphogenetic protein-2 （rhBMP2） to improve osteoblastic phenotype. Then marrow derived osteoblasts were seeded into poritos in density of 4 × 10^7/ml and incubated in vitro for 48 hours prior to implantation. Then osteoblastic cells/poritos complexes were implanted into mandibular defect and the defect was reinforced by titanium reticulum. Implantation of poritos alone acted as the control. Bone regeneration was assessed 4, 8, 16 weeks after implantation using roentgenographie analysis and histological observation was done after 16 weeks. Results： New bone could be observed histologically on the surface and in the pores of natural coral in all specimens in the cell-seeding group, whereas in the control group there was no evidence of osteogenesis process in the center of the construction. The results showed that new bone grafts were successfully restored 16 weeks after implantation. Conclusions： This study suggests the feasibility of using porous coral as scaffold material transplanted with marrow derived osteoblasts by TE method. By means of titanium reticulum reinforcement, mandibular defect could be successfully restored. It shows the potentiality of using this method for the reconstruction of bone defect in cfinic.
