Search

To achieve functional and esthetic results, implants must be placed accurately; however, little information is available regarding the effect of surgical templates on the accuracy of implant placement. Thus, the aim of this study was to measure the deviation between actual and planned implant positions, and determine the deviation caused by the surgical template.Jaws from 16 patients were scanned using cone beam computed tomography (CBCT). For our study, 53 implants were planned in a virtual 3D environment, of which 35 were inserted in the mandible and 18 in the maxilla. A stereolithographic (SLA) surgical template was created. A CBCT scan of the surgical template fitted on a plaster model was performed, and the images obtained were matched to virtual implant plan images that contained the planned implant position. The actual implant position was acquired from the registration position of the surgical template. Deviation between actual and planned implant positions was analyzed.Mean central deviation at the hex and apex was 0.456 mm and 0.515 mm, respectively. Mean value of horizontal deviation at the hex was 0.193 mm, horizontal deviation at the apex was 0.277 mm, vertical deviation at the hex was 0.388 mm, vertical deviation at the apex was 0.390 mm, and angular deviation was 0.621°.Our study results revealed a significant deviation between actual and planned implant positions caused by the surgical template.

To investigate the association between the single nucleotide polymorphisms (SNPs) in adiponectin gene promoter and essential hypertension (EH) in Chinese Korean and Han of Yanbian area, 220 EH patients and 268 normotensive control individuals were enrolled. PCR and direct DNA sequencing were used to determine the -11426AG (rs16861194), -11391GA (rs17300539), -11377CG (rs62620185), -11156insCA (rs60806105), and -11043CT (rs76786086) SNPs in the promoter region of adiponectin gene. Total cholesterol (TC), the triglyceride (TG), fasting plasma glucose (FPG), low density lipoprotein-cholesterol (LDL-C), and high density lipoprotein-cholesterol (HDL-C) levels were examined by oxi-dase method. The plasma adiponectin and insulin were measured by enzyme linked immunosorbent assay (ELISA). The results showed that: (1) SNPs of -11426AG, -11377CG, and -11156insCA were found and in Hardy-Weinberg equilib-rium (P0.05), but not the case in -11391GA and -11043CT. (2) -11426AG and -11156insCA were perfectly in link-age disequilibrium (D'=1; r2=1). (3) The allele G frequency of -11426AG polymorphism in Chinese Korean (21.10%) was significantly higher than that in Chinese Han (12.50%), and also higher in EH group than in the control group of Chinese Han. The genotype and allele frequencies of -11377CG showed no significant difference between the two groups ob-served. (4) The haplotype -11426G -11377C frequency in EH of Chinese Han was higher than in the control group (P0.05). (5) The EH showed lower plasma adiponectin level compared with the control group (P0.001) in both Chinese Korean and Han. Our results indicate that: (1) the perfect linkage disequilibrium of -11426AG and -11156insCA is first reported, and the SNP of -11426AG is associated with Chinese Han and Korean. (2) -11426 G and -11426G -11377C are risk factor and risk haplotype in Yanbian Chinese Han, but not in Chinese-Korean. (3) The lower hypoadiponectinemia is the important risk factors for EH in Chinese Korean and Han of Yanbian area. (4) There is no relationship between -11426AG polymorphism and the plasma adiponectin level.

Background The occurrence of mandibular defects caused by tumors has been continuously increasing in China in recent years. Conversely, results of the repair of mandibular defects affect the recovery of oral function and patient appearance, and the requirements for accuracy and high surgical quality must be more stringent. Digital techniques — including model reconstruction based on medical images, computer-aided design, and additive manufacturing — have been widely used in modern medicine to improve the accuracy and quality of diagnosis and surgery. However, some special software platforms and services from international companies are not always available for most of researchers and surgeons because they are expensive and time-consuming. Methods Here, a new technical solution for guided surgery for the repair of mandibular defects is proposed, based on general popular tools in medical image processing, 3D (3 dimension) model reconstruction, digital design, and fabrication via 3D printing. First, CT (computerized tomography) images are processed to reconstruct the 3D model of the mandible and fibular bone. The defect area is then replaced by healthy contralateral bone to create the repair model. With the repair model as reference, the graft shape and cutline are designed on fibular bone, as is the guide for cutting and shaping. The physical model, fabricated via 3D printing, including surgical guide, the original model, and the repair model, can be used to preform a titanium locking plate, as well as to design and verify the surgical plan and guide. In clinics, surgeons can operate with the help of the surgical guide and preformed plate to realize the predesigned surgical plan. Results With sufficient communication between engineers and surgeons, an optimal surgical plan can be designed via some common software platforms but needs to be translated to the clinic. Based on customized models and tools, including three surgical guides, preformed titanium plate for fixation, and physical models of the mandible, grafts for defect repair can be cut from fibular bone, shaped with high accuracy during surgery, and fixed with a well-fitting preformed locking plate, so that the predesigned plan can be performed in the clinic and the oral function and appearance of the patient are recovered. This method requires 20% less operating time compared with conventional surgery, and the advantages in cost and convenience are significant compared with those of existing commercial services in China. Conclusions This comparison between two groups of cases illustrates that, with the proposed method, the accuracy of mandibular defect repair surgery is increased significantly and is less time-consuming, and patients are satisfied with both the recovery of oral function and their appearance. Until now, more than 15 cases have been treated with the proposed methods, so their feasibility and validity have been verified.