A Three-Dimensional Morphological Assessment for Evaluating Pre- and Postsurgery in Cervical Laminoplasty.

OBJECTIVE: The efficacy of medical treatments and the changes in radiologic imaging before and after treatment have consistently remained pivotal factors. This is particularly critical for surgical procedures, where precise evaluation of disparities pre and postsurgery or the accuracy of implantation is paramount. Based on three-dimensional morphological interests, we provide an automatic quantification evaluation method that delivers an evident base for assessing the outcomes of a widely employed surgical technique, cervical laminoplasty. METHODS: The sample study included patients who underwent cervical laminoplasty for cervical spondylotic myelopathy/ossification of the longitudinal ligament. We present a superimposition method that facilitates a unique and precise assessment between pre and postsurgery. The degree of expansion was evaluated by the canal volume increase and canal expansion rate after surgery. RESULTS: There were 31 patients with 112 vertebral segments measured. The target cervical's pre and postoperative canal areas were 122.63 ± 30.34 and 196.50 ± 37.10 mm2, respectively (P < 0.001). The average cervical canal expansion rate was 64.42%. The expansion effect of C5 cervical laminoplasty was the maximum (71.01%), and the canal volume of other segments expanded by approximately 60%. The functional outcomes demonstrated significant improvements in symptoms. CONCLUSIONS: The quantification evaluation method can be utilized for any morphology changes before and after laminoplasty, as it does not lead to errors or variations from different inspection machines or human factors. The automatic method delivers an evident base for assessing the outcomes of a widely employed surgical technique.

Metacarpophalangeal joint reconstruction using a costal osteochondral graft: A case report.

RATIONALE: The conventional treatment of giant cell tumors is intralesional curettage with local adjuvant therapy. Because hand tumors have a high local recurrence, the primary goal for treating tumors of the hand is to eradicate the lesion. PATIENT CONCERNS: To preserve the metacarpophalangeal (MCP) joint function as well as avoid further recurrence after surgery. DIAGNOSES: The giant cell tumor invades the patient's MCP joint in an index proximal phalanx. INTERVENTIONS: Using computer-aided design and three-dimensional printing techniques, we reformed the original shapes of the MCP joint and its peripheral bone to replica models. The surgeon then performed an en bloc resection and proximal phalanx with MCP joint reconstruction by fabricating the patient's costal osteochondral graft during the operation. OUTCOMES: After 6 months of rehabilitation, the patient's finger functions could pinch and grasp objects naturally. At the 1-year follow-up, the range of motion of the MCP, proximal interphalangeal, and distal interphalangeal joints improved from flexion of 35° to 60°, 75° to 85°, and 60° to 80°, respectively. The hand function achieved the mean performance of non-preferred hands for young females at the postoperative 3-year follow-up. LESSONS: The customized prototyping technique has the potential to replica the original patient's bony graft to reach the goal of minimizing the defects at the donor site and maximizing the function of the reconstructed MCP joint.

Combining Laminoplasty With Artificial Disc Replacement for the Treatment of Cervical Spondylotic Myelopathy With Congenital Cervical Stenosis.

BACKGROUND: Cervical spondylotic myelopathy (CSM) is a very common and devastating spinal disease. Congenital cervical stenosis (CCS) is the most common cause. We aimed to elucidate the security, effectivity, and feasibility of surgery combining laminoplasty with artificial disc replacement (ADR) to treat CSM patients with radiculopathy, especially for preserving the range of motion (ROM) of the cervical spine. METHOD: Between August 2008 and April 2019, 39 patients with multiple CSM caused by CCS were enrolled in the present study. All patients received laminoplasty first and then ADR. We used a retrospective collection of data for evaluating the functional and radiologic outcomes, especially regarding preservation of ROM. RESULTS: Each patient underwent at least a 2-year postoperative follow-up. The Japanese Orthopedic Association score showed great improvements at 6 months. The ADR index-level ROM was preserved during follow-up. The subaxial Cobb angle could also be retained in the whole cervical spine, and the spinal canal diameter could be expanded by more than 52.6%. There were no severe complications or side effects, and no patients needed secondary surgery. CONCLUSIONS: We aimed to treat multiple levels of CSM with adequate decompression without too many intervertebral disc replacements. We were able to expand the spinal canal directly for these patients with CCS and needed only 1- or 2-level ADR to treat them with associated radiculopathy. This combined surgical strategy was secure, effective, and was able to preserve the ROM of the cervical spine.

A Symmetry-Based Superposition Method for Planning and Surgical Outcome Assessment.

Computer-aided surgical planning has been widely used to increase the safety and predictability of surgery. The validation of the target of surgical planning to surgical outcomes on a patient-specific model is an important issue. The aim of this research was to develop a robust superposition method to assess the deviation of planning and outcome by using the symmetrical characteristic of the affected target. The optimal symmetry plane (OSP) of an object is usually used to evaluate the degree of symmetry of an object. We proposed a refined OSP-based contouring method to transfer a complex three-dimensional superposition operation into two dimensions. We compared the typical iterative closest point (ICP) algorithm with the refined OSP-based contouring method and examined the differences between them. The results using the OSP-based method were much better than the traditional method. As for processing time, the OSP-based contouring method was 11 times faster than the ICP method overall. The proposed method was not affected by the metallic artifacts from medical imaging or geometric changes due to surgical intervention. This technique can be applied for post-operative assessment, such as quantifying the differences between surgical targets and outcomes as well as performing long-term medical follow-up.

An Automatic Voxel-Based Method for Optimal Symmetry Plane Generation for the Maxillofacial Region in Severe Asymmetry Cases.

Symmetry is representative of aesthetics and health in all kinds of vertebrates, especially the human face. Therefore, to automatically locate the appropriate symmetry plane is crucial. The aim of this study was to develop an automatic and reliable method to determine the symmetry plane of the maxillofacial region. We compared the proposed method of determining the symmetry plane by assessing landmark-based and surface-based methods by way of quantitative symmetry assessments. Statistical analysis was applied to evaluate whether significant difference existed among these three kinds of symmetry planes. Twenty cases who had a diagnosis of severe facial asymmetry were evaluated retrospectively. The results showed that searching for the symmetry plane using a voxel-based method, named the optimal symmetry plane (OSP), achieved the most representative symmetry according to the outcomes of the trials. The OSP was significantly more symmetrical than the other two planes, as determined by other methods. The paired-voxel computation method proposed in this research is a robust and reliable method for identifying the unique symmetry plane for patients with severe facial asymmetry. Symmetry is of crucial significance for all kinds of vertebrates, including its clinical implications for surgical planning in orthognathic surgery.

Supercritical Carbon Dioxide Decellularized Xenograft-3D CAD/CAM Carved Bone Matrix Personalized for Human Bone Defect Repair.

About 30-50% of oral cancer patients require mandibulectomy and autologous fibula reconstruction. Autograft is the gold standard choice because of its histocompatibility; however, it requires additional surgery from the patient and with possible complications such as loss of fibula leading to calf weakening in the future. Allograft and xenograft are alternatives but are susceptible to immune response. Currently, no personalized bone xenografts are available in the market for large fascial bone defects. In addition, a large-sized complex shape bone graft cannot be produced directly from the raw material. We propose the use of porcine bones with 3D CAD/CAM carving to reconstruct a personalized, wide range and complex-shaped bone. We anticipate that patients can restore their native facial appearance after reconstruction surgery. Supercritical CO2 (SCCO2) technology was employed to remove the cells, fat and non-collagenous materials while maintaining a native collagen scaffold as a biomedical device for bone defects. We successfully developed 3D CAD/CAM carved bone matrices, followed by SCCO2 decellularization of those large-sized bones. A lock-and-key puzzle design was employed to fulfil a wide range of large and complex-shaped maxillofacial defects. To conclude, the 3D CAD/CAM carved bone matrices with lock and key puzzle Lego design were completely decellularized by SCCO2 extraction technology with intact natural collagen scaffold. In addition, the processed bone matrices were tested to show excellent cytocompatibility and mechanical stiffness. Thus, we can overcome the limitation of large size and complex shapes of xenograft availability. In addition, the 3D CAD/CAM carving process can provide personalized tailor-designed decellularized bone grafts for the native appearance for maxillofacial reconstruction surgery for oral cancer patients and trauma patients.

Reconstruction of three-dimensional lumbar vertebrae from biplanar x-rays.

Objective. Vertebrae models from computer tomographic (CT) imaging are extensively used in image-guided surgical systems to deliver percutaneous orthopaedic operations with minimum risks, but patients may be exposed to excess radiation from the pre-operative CT scans. Generating vertebrae models from intra-operative x-rays for image-guided systems can reduce radiation exposure to the patient, and the surgeons can acquire the vertebrae's relative positions during the operation; therefore, we proposed a lumbar vertebrae reconstruction method from biplanar x-rays.Approach. Non-stereo-corresponding vertebral landmarks on x-rays were identified as targets for deforming a set of template vertebrae; the deformation was formulated as a minimisation problem, and was solved using the augmented Lagrangian method. Mean surface errors between the models reconstructed using the proposed method and CT scans were measured to evaluate the reconstruction accuracy.Main results. The evaluation yielded mean errors of 1.27 mm and 1.50 mm inin vitroexperiments on normal vertebrae and pathological vertebrae, respectively; the outcomes were comparable to other template-based methods.Significance. The proposed method is a viable alternative to provide digital lumbar to be used in image-guided systems, where the models can be used as a visual reference in surgical planning and image-guided applications in operations where the reconstruction error is within the allowable surgical error.

[Effect of calorie-enriched formula on postoperative catch-up growth in infants with cyanotic congenital heart disease: a propective randomized controlled study].

OBJECTIVE: To study the effect of calorie-enriched formula on postoperative catch-up growth in infants with cyanotic congenital heart disease (CHD). METHODS: A total of 100 infants with cyanotic CHD who underwent surgical operation from January to December, 2017, were randomly divided into a high-calorie group (receiving calorie-enriched formula after surgery) and a conventional group (receiving standard formula after surgery), with 50 infants in each group. All infants were followed up for 6 months. The observation indices included body height, body weight, prealbumin, and N-terminal pro-brain natriuretic peptide before surgery, at the time of ventilator weaning and extubation after surgery, and at 1, 3, and 6 months after surgery. Height-for-age Z-score (HAZ), weight-for-age Z-score (WAZ), and weight-for-height Z-score (WHZ) were also assessed. Adverse reactions were recorded for both groups. RESULTS: There were 25 cases (50%) and 21 cases (42%) of malnutrition in the high-calorie group and the conventional group respectively before surgery (P > 0.05). The nutritional status of the two groups improved 6 months after surgery (P < 0.05). At 6 months after surgery, compared with the conventional group, the high-calorie group had a lower proportion of infants with malnutrition (18% vs 36%, P < 0.05) and also a lower proportation of infants with a WAZ score of < -2 (P < 0.05). The infants with malnutrion in the high-calorie group had higher HAZ, WAZ, and WHZ than those in the conventional group (P < 0.05). No gastrointestinal intolerance was observed in both groups during hospitalization. CONCLUSIONS: Compared with the standard formula, calorie-enriched formula can better help with postoperative catch-up growth in infants with cyanotic CHD.

Molecular docking simulation and in vitro studies on estrogenic activities of flavonoids from leaves of Carya cathayensis Sarg.

The main purpose of this study was to evaluate the estrogenic properties of total flavonoids (TFs) and five flavonoid monomers (cardamonin (Car), pinostrobin chalcone (PC), wogonin (Wo), chrysin (Chr) and Pinocembrin (PI)) from leaves of Carya cathayensis Sarg (LCC). TFs from LCC were isolated and determined using HPLC. The 3-[4,5-dimethylthiazole-2-yl]-2,5-diphenyltetrazolium bromide (MTT) assay and flow cytometry were performed to assess the effects of flavonoids on cell proliferation and cell cycle, respectively. The molecular docking technique was applied to investigate binding conformations of the monomers from LCC to the estrogen receptor ERα and ERß. Gene and protein expression patterns were assessed using quantitative real-time PCR (qRT-PCR) and western blot, respectively. The results showed that TFs, Car, PC, Wo and Chr promoted proliferation of MCF-7 cells and cell transition from the G1 to S phase, and inhabitation of MCF-7 cell proliferation was observed after the treatment of PI. Molecular docking studies confirmed ERs as molecular targets for the monomers. TFs, Car, PC, Wo and Chr from LCC promoted gene expression of ERα, ERß, progesterone receptor (PR) and pS2. Our collective results demonstrated that TFs and monomers from LCC may exert ER agonist activity through competitively bind to ER, inducing ER upregulation and active ER to estrogen response element (ERE)- independent gene regulation. As an abundant natural product, LCC may provide a novel medicinal source for treatment of diseases caused by estrogen deficiency.

3D-Customized Guiding Template for Posterior Fixation in Complex Atlantoaxial Instability-Preliminary Experiences of National Cheng Kung University Hospital.

Objective Atlantoaxial fixation is technically demanding and challenging, especially in cases with anatomical abnormality. The purpose of this study is to report the effectiveness of the three-dimensional (3D)-customized guiding template for placement of C1 and C2 screws in cases with abnormalities. Method Two patients with anatomical abnormality and one without were included. The preoperative computed tomography (CT) image was analyzed using our software. The entry point, trajectory, and depth of the screws were designed based on these images. Templates with screw guiding cylinders and cervical spine model were created. In operation, guiding templates were applied directly to the laminae. Drilling, tapping, and screwing were performed through the cylinders. To evaluate the accuracy, deviation of the screw axis from the preplanned trajectory was measured on postoperative CT. A classification system was taking to evaluate the pedicle screw insertion. Results In complex cases, one of C2 screws has grade 2 deviation, and two has grade 1. There was no deviation in screws of C1. All patients achieved symptoms free after 6 months follow-up. Conclusion Although 3D-printed template for atlantoaxial fixation still has limitation in complex cases, it has been proved usefulness and makes the most difficult and dangerous spinal posterior fixation easy to achieve.

Short-segment decompression and fixation for thoracolumbar osteoporotic fractures with neurological deficits.

Objective We assessed our results of short-segment decompression and fixation for osteoporotic thoracolumbar fractures with neurological deficits. Methods We evaluated 20 elderly patients (age, 60-89 years; mean, 73.2 years) with osteoporotic thoracolumbar fractures and neurological deficits. They underwent short-segment decompression and fixation and followed up for 40.6 (range, 24-68) months. A visual analog scale (VAS) and the Oswestry Disability Index (ODI) were used to measure back pain and disability. We also analyzed patients' radiologic findings and neurological status. Perioperative and postoperative complications were recorded. Results At the latest follow-up, the average VAS score for back pain and ODI scores had significantly improved. The radiologic assessment showed significant improvements in local kyphosis, anterior vertebral height, and the vertebral wedge angle compared with the original measures. Neurological function also improved in 18 of 20 patients. No major complications occurred perioperatively. Our techniques included preservation of the posterior ligament complex, decortication of facet joints for fusion, no tapping to increase the screw insertional torque, pre-contouring of the rods according to the "adaptive" curve obtained from postural reduction, and postoperative spinal bracing. Conclusions Posterior short-segment decompression and fixation could be an effective surgical option for osteoporotic thoracolumbar burst fractures with neurological deficits.

Accuracy and Safety of Using Customized Guiding Templates for Cervical Pedicle Screw Insertion in Severe Cervical Deformity, Fracture, and Subluxation: A Retrospective Study of 9 Cases.

OBJECTIVE: To assess accuracy and safety of self-developed customized guiding templates for cervical pedicle screw (CPS) insertion surgery. METHODS: From July 2016 to December 2017, 57 screws were implanted in 9 patients with the assistance of customized guiding templates. Customized guiding templates were manufactured from acrylonitrile-butadiene-styrene plastic material using a three-dimensional printer after establishing pedicle screw trajectories for each vertebra with the assistance of a virtual surgical planning software program, developed by our team, for the insertion of CPSs. RESULTS: CPSs were evaluated using the following grading system: grade 0 (contained), grade 1 (exposure), grade 2 (perforation), and grade 3 (penetration). Each patient underwent postoperative computed tomography to evaluate accuracy of screw position. Of 57 screws, 54 were graded 0, and 3 were graded 1; no screws were graded 2 or 3. No vascular or nerve injuries were noted after the operations. CONCLUSIONS: CPSs, which provide strong biologic strength, are especially suitable for treating osteoporosis and severe deformity. However, CPS insertion remains a challenging procedure with high incidences of vascular and nerve injuries reported. The results of this study indicate that use of customized guiding templates can improve safety of CPS insertion surgery.

Resection of giant invasive sacral schwannoma using image-based customized osteotomy tools.

BACKGROUND: Giant invasive sacral schwannomas are rare tumors. Surgical excision is the standard treatment and total resection is performed if feasible. Advances in three-dimensional (3D) imaging technology have facilitated treatment designs of complex surgical procedures. OBJECTIVE: Our aim was to evaluate virtual surgical planning, computer-aided design (CAD), and manufacturing with 3D printing technology of the customized osteotomy guiding device in giant invasive sacral schwannoma resection. METHODS: A digital 3D model of the sacrum, including the giant invasive sacral schwannoma, was rendered from patient computer tomography (CT) images. The surgeon chose excision margins of the tumor. Based on the virtual surgical planning, the customized guiding tool for osteotomy was designed and manufactured using the CAD and 3D printing. RESULTS: We used the guiding block to successfully excise a giant sacral schwannoma using only a posterior approach to achieve gross total resection. No augmented spinal instrumentation was used to prevent iatrogenic spinal instability. Clinical symptoms resolved dramatically after operation. No spinal instability occurred during follow-up. CONCLUSION: With the assistance of an image-based customized osteotomy guiding device, we achieved both goals of tumor resection and bone preservation in giant sacral schwannoma resection. With thorough surgical planning, this technology can be applied to the complex surgical procedures easily and reliably.

Use of the matching optimal symmetry plane method in planning surgical correction of facial asymmetry--a preliminary report of 20 patients.

PURPOSE: A voxel-based median plane (optimal symmetry plane [OSP]) was developed to assess facial bone asymmetry. The purpose of the present study was to introduce a new method of planning surgical correction of facial asymmetry using the OSPs as guides and test its effectiveness. PATIENTS AND METHODS: A retrospective study was conducted of 20 facial asymmetry patients with a mandibular deviation of 4 mm or greater or 4° or more that required surgical correction. In the test group (n = 8), the plans for asymmetry correction were formulated using the matching OSP method, in which the OSPs of the facial bones are tracked and matched during the model surgery setup. In the control group (n = 12), traditional planning was conducted. The traditional plans were cross-checked for symmetry through tracking and revised as needed. The symmetry results of the plans were compared between the 2 groups and within the control group. The outcome measures were the deviation distances between the OSPs of the midface and mandible at the anterior or posterior mandible, the occlusal plane cant, and the angle formed by the 2 OSPs. Surgery was performed in accordance with the final plans, and the results were assessed for symmetry. RESULTS: The traditional plans left a major mandibular deviation in 5 of the 12 control subjects compared with none in the test group. The test group did significantly better than the control group. The revised plans were significantly better than the initial plans. Postoperatively, significant improvements in symmetry were observed. CONCLUSION: The new method resulted in surgical plans that brought about significantly less postoperative mandibular deviation while maintaining a reasonable occlusion.

Effect of spleen lymphocytes on the splenomegaly in hepatocellular carcinoma-bearing mice.

OBJECTIVE: To study the effect of spleen lymphocytes on the splenomegaly by hepatocellular carcinoma-bearing mouse model. METHODS: Cell counts, cell cycle distribution, the percentage of lymphocytes subsets and the levels of IL-2 were measured, and two-dimensional gel electrophoresis (2-DE) was used to investigate the relationship between spleen lymphocytes and splenomegaly in hepatocellular carcinoma-bearing mice. RESULTS: Compared with the normal group, the thymus was obviously atrophied and the spleen was significantly enlarged in the tumor-bearing group. Correlation study showed that the number of whole spleen cells was positively correlated with the splenic index. The cell diameter and cell-cycle phase distribution of splenocytes in the tumor-bearing group showed no significant difference compared to the normal group. The percentage of CD3+ T lymphocytes and CD8+ T lymphocytes in spleen and peripheral blood of tumor-bearing mice were substantially higher than that in the normal mice. Meanwhile, the IL-2 level was also higher in the tumor-bearing group than in the normal group. Furthermore, two dysregulated protein, ß-actin and S100-A9 were identified in spleen lymphocytes from H22-bearing mice, which were closely related to cellular motility. CONCLUSION: It is suggested that dysregulated ß-actin and S100-A9 can result in recirculating T lymphocytes trapped in the spleen, which may explain the underlying cause of splenomegaly in H22-bearing mice.

Complex facial deformity reconstruction with a surgical guide incorporating a built-in occlusal stent as the positioning reference.

Computer-aided design has gained increasing popularity in clinical practice, and the advent of rapid prototyping technology has further enhanced the quality and predictability of surgical outcomes. It provides target guides for complex bony reconstruction during surgery. Therefore, surgeons can efficiently and precisely target fracture restorations. Based on three-dimensional models generated from a computed tomographic scan, precise preoperative planning simulation on a computer is possible. Combining the interdisciplinary knowledge of surgeons and engineers, this study proposes a novel surgical guidance method that incorporates a built-in occlusal wafer that serves as the positioning reference.Two patients with complex facial deformity suffering from severe facial asymmetry problems were recruited. In vitro facial reconstruction was first rehearsed on physical models, where a customized surgical guide incorporating a built-in occlusal stent as the positioning reference was designed to implement the surgery plan. This study is intended to present the authors' preliminary experience in a complex facial reconstruction procedure. It suggests that in regions with less information, where intraoperative computed tomographic scans or navigation systems are not available, our approach could be an effective, expedient, straightforward aid to enhance surgical outcome in a complex facial repair.

Optical tracking-based model surgery for orthognathic surgical planning using a quantifying evaluation method.

Traditional cephalometry with a cast-mounted articulator is a useful and well-established tool for orthognathic surgery 7 planning. However, 2-D planning with dental casts cannot provide 8 comprehensive information on facial bone conditions, especially 9 with regards to symmetry. To plan and predict postsurgical facial 10 symmetry and occlusions, this paper uses an optical navigation system to track the movement of the upper and lower dental models 12 in model surgery. The corresponding movement and the new position of the jawbones are demonstrated in the computer and the 14 symmetry status can be evaluated. Surgical splints can be fabricated from the virtual models and used in surgery. The procedure 16 provides more realistic predictions, which can assist surgeons to 17 better control postsurgical facial harmony.

Polymorphism of vascular endothelial growth factor -2578C/A with cancer risk: evidence from 11263 subjects.

Published data on the association between vascular endothelial growth factor (VEGF) -2578C/A polymorphism and cancer risk is inconclusive. To derive a more precise estimation of association between VEGF -2578C/A polymorphism and the risk of cancer, we performed a meta-analysis of 5415 cancer cases and 5848 controls from 16 published case-control studies. We used odds ratios (ORs) with 95% confidence intervals (CIs) to assess the strength of the association. Our meta-analysis indicated that VEGF -2578C/A polymorphism was associated with the risk of colorectal cancer under homozygote comparison (OR=0.70, 95% CI=0.53-0.92), dominant model (OR=0.72, 95% CI=0.57-0.92), and recessive model (OR=0.82, 95% CI=0.67-1.01), although no evidence of association between VEGF -2578C/A polymorphism and cancer risk was observed as we compared in the pooled analyses (homozygote comparison: OR=0.97, 95% CI=0.81-1.16). More studies are needed to detect VEGF -2578C/A polymorphism and its association with cancer in different ethnic populations incorporated with environmental exposures in the susceptibility of different kinds of cancer.

Vascular endothelial growth factor +936C/T and +405G/C polymorphisms and cancer risk: a meta-analysis.

BACKGROUND AND AIMS: A number of investigators have studied the possible association between vascular endothelial growth factor (VEGF) polymorphisms and cancer risk, but the results have been conflicting. To examine the risk of cancer associated with the +936C/T and +405G/C polymorphisms of VEGF, all available studies were considered in the present meta-analysis. METHODS: We performed a computerized search of PubMed and Embase database for relevant studies. Articles meeting the inclusion criteria were reviewed systematically, and the reported data were aggregated using the statistical techniques of meta-analysis. RESULTS: Overall, the 936C allele showed no significant effect on cancer risk compared with the 936T allele in all subjects (OR = 0.77, 95% CI = 0.53-1.14; random model). Similarly, no significant effect of 405G allele compared with 405C on cancer risk was found (OR = 1.08, 95% CI = 0.94-1.24; random model). It indicated that the VEGF +936C/T and +405G/C polymorphisms might not be risk factors for cancer, but the 936C allele was associated with a decreased risk of oral cancer (OR = 0.72, 95% CI = 0.53-0.97; fixed model). CONCLUSIONS: The evidence from our meta-analysis supports that there was an association between 936C allele and decreased oral cancer risk, although no evidence of association between VEGF +936C/T or +405G/C polymorphism and cancer was observed in all examined patients. Further studies based on larger, stratified population are required to explore the role of VEGF polymorphisms on cancer risk.

Modelling of mandibular movement.

In this paper, the authors presented a novel method to reconstruct individual mandible movement in three dimensions by a virtual articulator system. The system provides a synchronized 3D mandibular movement that faithfully reappear one's natural occlusion movements--sagittal border, lateral, and open-close movements. Movement trajectories are approximated by cubic or high-degree curves modelling. During the whole process, X-ray exposure on human is avoided. The authors apply the optimal methodology to approach the collected samples of movements in order to generate specific occlusion curves and surfaces. The system provides a novel method of mimicking occlusion of individuals. It is a useful tool for recording dynamic movements of an individual in both pre- and post-surgery and also for predicting surgical outcomes.