ABSTRACT
BACKGROUND:Using three dimensional (3D) reconstruction techniques,any part of body is accessible to visual observation.However,reports concerning 3D reconstruction of craniofacial vascularity based on PC are few in China.OBJECTIVE:To explore the method and the application values of reconstructing a digital 3D model of craniofacial vascularity based on the data of CT strengthening scanning.METHODS:CT strengthening scan images from a healthy volunteer in DICOM format were imported into Mimics 10.01 software and craniofacial blood vessels were reconstructed with the technique of thresholding,editing and 3D region growing.RESULTS AND CONCLUSION:The 3D digital model of craniofacial blood vessels was obtained.This model could be zoomed and rotated randomly and displayed the spatial positions and adjacent relationships of different anatomical structures,also the reconstructed structures could be measured in 3D space.The 3D digital model of craniofacial blood vessels can be reconstructed conveniently and quickly with Mimics software on PC,and also it can bring morphological reference to human anatomy teaching,clinical neurosurgery,oral and maxillofacial surgery,as well as image diagnosis,and will be helpful to generate a virtual plateform in craniofacial surgery.
ABSTRACT
Anatomic structure in craniofacial region is very complicated and orthognathic surgery is difficultly performed.Therefore,it is necessary to generate virtual surgical model from CT scan data before operation on personal computer in order to make surgery more accurate.This technique has been increasingly interested in the field of orthognathic surgery both at home and abroad.The sample was scanned with thin-layer CT.CT image data (336 layer,1.0 mm slice thickness) were analyzed with the Mimics software.Simultaneously,three-dimensional model and virtual surgery of the facial cranium were established.The digitized virtual surgical platform of facial cranium was preliminarily created,and three common surgical methods in maxillofacial surgery,i.e.,LeFort Ⅰ osteotomy,mandibular angle osteotomy,and genioplasty,for maxillofacial surgery were simulated.The results showed that the digitized virtual surgical platform of facial cranium could be generated with the Mimics software on personal computer,which provides convenient and quick methods for research,teaching,and clinical surgery.More importantly,it creates theoretical basis for virtual surgical platform which can be widely used on personal computer.
ABSTRACT
BACKGROUND: Chitin and its derivatives possess many biological activities such as immune modulation and promoting wound healing and hemostasis. As one of the derivatives of chitin, the effect of N-acetylglu cosamine on fracture healing has not yet been acknowledged.OBJECTIVE: To observe the changes in osteoblastic activity and the expression of bone morphogenetic protein (BMP) in response to the intervention with N-acetylglucosamine during the fracture healing. DESIGN: A randomized controlled experiment SETTING: Department of Anatomy, Medical College of Qingdao University.MATERIALS: This experiment was carried out in the Laboratory of Neuroanatomy, Medical Colloge of Qingdao University from March to August 2002. Seventy healthy New Zealand rabbits were randomized into four groups, namely saline group (n=23), Jiegupian group (n=23) and N-acetyl glucosamine group (n=24).METHODS: The rabbits were subjected to operations to induce 3-mm bone defect in the middle segment of the right radius with subsequent treatments with saline (1.00 mL/kg), Jiegupian (1.00 mL/kg) and N-acetyl glucosamine (0.28 g/kg) via intragastric administration on a daily basis till the time of tissue sampling at postoperative days 9, 17, 30 and 42, respectively. X-ray examination and HE staining were performed to observe the healing process, and the expression of BMP was assessed immunohistochemically.MAIN OUTCOME MEASURES :① General condition of the rabbits after operation; ② Fracture healing process revealed by X-ray at the specified time points; ③ Expression of BMP between the fracture ends at each time point; ④ Results of histological observation.RESULTS: According to intent-to-treat analysis, 70 rabbits entered the data analysis. X-ray revealed better fracture healing in N-acetylglucosamine group than in the ither two groups at postoperative days 9, 17, 30 and 42(P ＜ 0.05). Compared with saline group, the expression of BMP protein in Jiegupian group and N-acetylglucosamine group was increasing at postoperative 9 and 17 days, particularly in the latter group (P ＜ 0.05), but decreased at postoperative 30 and 42 days. Histologically, the gap between the fracture ends reduced in N-acetylglucosamine group at postoperative 9 days with the appearance of ()bmogenous bone trabecula an orderly arrangement of osteoblasts; in saline group, the gap was greater and contained less or even no bone trabecula, with much less, if any, osteoblasts.On postoperative day 30, the bone defect were completely filled by bone trabecula in N-acetylglucosamine group, with the bone trabecula almost communicating with the bone marrow cavity, and the osteoblasts surrounding the bone trabecula were arranged orderly with osteoclasts seldom observed; in saline group, the defect was substituted mostly by bone trabecula with breaches, and the chondrocytes could be observed scarcely. On postoperative day 42, the bone plate woven bone formed primarily at the fracture ends in N-acetylglucosamine group, with completely communicating marrow cavity and numerous active osteoclasts, and osseous lacuna can be observed; in saline group, the defect was filled with bone trabecula but clear fusion lines were not seen, and communication of the bone marrow cavity was nearly achieved with orderly arranged osteoblasts and presence of the osteoclasts.CONCLUSION: N-acetylglucosamine can accelerate fracture healing possibly by promoting the osteoblastic activity and increase the expression of BMP during the early period of fracture healing.
ABSTRACT
To advocate cadaver donation is to advocate the spirit of devotion and scientific research.It has been proved in the development of modern medicine that many problems of medical education and stubborn diseases were solved by necrospy.However,currently the cadavers donated cannot satisfy practical need,mainly because that few people would voluntarily register to donate their bodies,and those among the registered who actually donated are even fewer.This paper analyzes three factors that contribute to the bottleneck in the cadaver donation.And on the basis of present situation,countermeasures are presented to solve the problems.