Neovascularization is the basis of tumor growth and metastasis. Angiogenesis depends mainly on the regulation of vascular endothelial growth factor and angiogenesis inhibiting factor. The vascular endothelial growth factor and its receptor are the most important and are studied most. The expression of them increased significantly in gastric cancer tissue and serum.. They promote angiogenesis of tumor. They are closely related to the prognosis of patient. The vascular endothelial growth factor and its receptor in the gastric cancer are reviewed in this article.

Digital intraoral scanning is a hot topic in the field of oral digital technology.In recent years,digital intra-oral scanning has gradually become the mainstream technology in orthodontics,prosthodontics,and implant dentistry.The precision of digital intraoral scanning and the accuracy and stitching of data collection are the keys to the success of the impression.However,the operators are less familiar with the intraoral scanning characteristics,imaging process-ing,operator scanning method,oral tissue specificity of the scanned object,and restoration design.Thus far,no unified standard and consensus on digital intraoral scanning technology has been achieved at home or abroad.To deal with the problems encountered in oral scanning and improve the quality of digital scanning,we collected common expert opin-ions and sought to expound the causes of scanning errors and countermeasures by summarizing the existing evidence.We also describe the scanning strategies under different oral impression requirements.The expert consensus is that due to various factors affecting the accuracy of digital intraoral scanning and the reproducibility of scanned images,adopting the correct scanning trajectory can shorten clinical operation time and improve scanning accuracy.The scanning trajec-tories mainly include the E-shaped,segmented,and S-shaped methods.When performing fixed denture restoration,it is recommended to first scan the abutment and adjacent teeth.When performing fixed denture restoration,it is recommend-ed to scan the abutment and adjacent teeth first.Then the cavity in the abutment area is excavated.Lastly,the cavity gap was scanned after completing the abutment preparation.This method not only meets clinical needs but also achieves the most reliable accuracy.When performing full denture restoration in edentulous jaws,setting markers on the mucosal tissue at the bottom of the alveolar ridge,simultaneously capturing images of the vestibular area,using different types of scanning paths such as Z-shaped,S-shaped,buccal-palatal and palatal-buccal pathways,segmented scanning of dental arches,and other strategies can reduce scanning errors and improve image stitching and overlap.For implant restora-tion,when a single crown restoration is supported by implants and a small span upper structure restoration,it is recom-mended to first pre-scan the required dental arch.Then the cavity in the abutment area is excavated.Lastly,scanning the cavity gap after installing the implant scanning rod.When repairing a bone level implant crown,an improved indi-rect scanning method can be used.The scanning process includes three steps:First,the temporary restoration,adjacent teeth,and gingival tissue in the mouth are scanned;second,the entire dental arch is scanned after installing a standard scanning rod on the implant;and third,the temporary restoration outside the mouth is scanned to obtain the three-di-mensional shape of the gingival contour of the implant neck,thereby increasing the stability of soft tissue scanning around the implant and improving scanning restoration.For dental implant fixed bridge repair with missing teeth,the mobility of the mucosa increases the difficulty of scanning,making it difficult for scanners to distinguish scanning rods of the same shape and size,which can easily cause image stacking errors.Higher accuracy of digital implant impres-sions can be achieved by changing the geometric shape of the scanning rods to change the optical curvature radius.The consensus confirms that as the range of scanned dental arches and the number of data concatenations increases,the scanning accuracy decreases accordingly,especially when performing full mouth implant restoration impressions.The difficulty of image stitching processing can easily be increased by the presence of unstable and uneven mucosal mor-phology inside the mouth and the lack of relatively obvious and fixed reference objects,which results in insufficient ac-curacy.When designing restorations of this type,it is advisable to carefully choose digital intraoral scanning methods to obtain model data.It is not recommended to use digital impressions when there are more than five missing teeth.

To explore the technical process and the therapeutic effect of using sequential surgical guide with independent intellectual property rights assisting immediate implantation and restoration of the full arch, with the support from the periodontal splint for mobile supporting teeth, patients with severe periodontitis who planned to undergo immediate full arch implantation were recruited from August 2019 to December 2020 at the Department of Prosthodontics, Department of Periodontology, Department of Implantology and First Clinical Division, Peking University School and Hospital of Stomatology. Through the procedure of collecting preoperative maxillofacial data, making systematic diagnostic design, making periodontal splints fixation, producing surgical guide, and carrying out guided surgery for full arch immediate implantation, eight cases were included. By registering the postoperative cone-beam CT (CBCT) with the preoperative data, the difference between the actual three-dimensional position of the implants and the virtual design was observed, and the accuracy of the implant placement position guided by the sequential guide was statistically analyzed using SPSS 25.0 software. Analysis indicators include coronal and apical global displacement, coronal horizontal and vertical displacement, apical horizontal and vertical displacement, and angular deviation. Results revealed that the 8 patients [2 males and 6 females, aged (49.0±9.3) years (38-65 years)] of recruited cases included 7 cases of maxilla and 1 cases of mandible. A total of 48 implants, of which 44 implants were placed upright and 4 were placed tilted, 16 implants in the anterior region and 32 implants in the posterior region. No guide plate fracture or damage to important anatomical structures were reported. The overall displacement at the coronal point [(0.83±0.48) mm] and the global displacement at the apical point [(1.36±0.57) mm] were within the clinically acceptable safety range, and the horizontal displacement and vertical displacement at the coronal point, horizontal displacement and vertical displacement at the apical point, and the angle deviation of implants axial have no statistic significant difference in the anterior and posterior region ( P>0.05). Periodontal splints combined with sequential surgical guides to assist patients with severe periodontitis for immediate full arch implantation and immediate restoration can expand the indications of guide assisted implant surgery. It meets the safety requirements in clinical applications.