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.

This article reports one case of adult COVID-19-associated acute necrotizing encephalopathy(ANEC).The patient developed disturbance of consciousness and seizure on the 12th day after SARS-CoV-2 infection.Imaging showed significant swelling and signal changes in the bilateral thalamus,brainstem,cerebral hemisphere and cerebellar hemisphere,which were consistent with the characteristic images of Acute necrotizing encephalitis(ANE).Although methylprednisolone shock therapy and high-dose human immunoglobulin therapy were given early,the patient died.ANEC often starts quickly and progresses rapidly,unconsciousness and seizure are the main manifestations.Imaging features of thalamic and subtentorial symmetry and multifocal lesions are specific for diagnosis,but the treatment and prognosis still face challenges and need further study.

Purpose To explore the value of iodine concentration(IC)and effective atomic number(Zeff)derived from dual-layer spectral detector CT in diagnosing the regional lymph nodes of gastric cancer.Materials and Methods From May 2021 to September 2022,108 patients pathologically confirmed with gastric cancer(92 non-metastatic lymph nodes and 116 metastatic lymph nodes),who underwent dual-phase enhanced dual-layer spectral detector CT scanning preoperatively in the Second Affiliated Hospital of Guangzhou University of Chinese Medicine,were included in the study.The imaging and clinical data of all cases were collected,retrospectively.According to preoperative CT images,the short diameter,margin and enhancement homogeneity of the lymph nodes were evaluated.The IC and Zeff were obtained from the delineated region of interest of the solid portion of the maximum layer of the target lymph nodes,and the normalization IC(nIC)and normalization Zeff(nZeff)were calculated.The difference of parameters between two groups were compared.The efficiency of differential diagnosis and combined diagnosis of each parameter was analyzed.The area under the receiver characteristic curve(AUC)for each parameter were compared.Results There were statistical differences in short diameter,margin and enhancement homogeneity between the two groups(t/x2=-7.575,30.971,20.913,all P＜0.001).In the benign lymph nodes group,all spectral parameters in the arterial phase(AP)were lower than those in malignant lymph nodes,while the parameters in the venous phase(VP)were higher(t=-10.723-12.610,all P＜0.001).Among the three conventional features,the AUC of short diameter was the highest(0.749).Compared with the AUC values of ICAP and ZeffVP,the AUC values of short diameter and quantitative parameters had no statistical difference(P＞0.05),but were lower than those of other spectral parameters.Among the spectral parameters,the AUC value of nICVP was the highest(0.925).The sensitivity and specificity of the spectral parameters were higher than those of conventional features.The diagnostic efficacy of the multi-parameter combined model was superior to that of the univariate model.The AUC value of the combined model with conventional features was 0.815.Among the combined model based on CT spectral parameters,the diagnostic efficacy of model combined with the parameters of arteriovenous phase was the highest(AUC=0.993).Conclusion The quantitative parameters of dual-phase enhancement derived from dual-layer spectral detector CT can effectively evaluate the characteristics of gastric cancer regional lymph nodes,and the diagnostic efficiency is higher than the conventional characteristics of lymph nodes.The multi-parameter combined model can improve the diagnostic efficiency.

Objective:To evaluate the efficacy of high-flow nasal cannula (HFNC) oxygen therapy in optimizing painless transesophageal echocardiography in elderly patients.Methods:Sixty American Society of Anesthesiologists Physical Status classification Ⅱ patients, regardless of gender, aged 60-75 yr, with body mass index of 18.5-23.9 kg/m 2, were randomized into 2 groups ( n=30 each) by a random number table method: group HFNC and conventional ventilation group (group C). Pure oxygen 10 L/min was inhaled for 3 min preoxygenation using the HFNC device in group HFNC. Group C inhaled pure oxygen at 6 L/min for 3 min preoxygenation via a nasal cannula. Sufentanil 0.1 μg/kg and remazolam 0.25-0.30 mg/kg were intravenously injected in turn. Group HFNC was connected to a high-flow humidification oxygen therapy device and inhaled pure oxygen at 60 L/min (37℃, FiO 2 100%). The flow rate of pure oxygen was maintained at 6 L/min (FiO 2 100 %) in group C. The patients were placed in left lateral decubitus position, esophageal ultrasound was performed after the eyelash reflex disappeared, and remazolam 0.1 mg/kg was intravenously injected intermittently when bucking and body movement were induced by operation stimulation. The occurrence of hypoxia-related adverse events, mandibular intervention and ventilation-related adverse events was observed during examination. The operation time, time of emergence from anesthesia and consumption of remazolam were recorded. Results:Compared with group C, the incidence of severe hypoxia and rate of mandibular intervention were significantly decreased (7%/0 and 53%/17%, P<0.05), the lowest intraoperative SpO 2 was increased ( P<0.05), and no significant change was found in the operation time, time of emergence from anesthesia and consumption of remazolam in group HFNC ( P>0.05). No ventilation-related adverse events occurred in both groups. Conclusions:HFNC can markedly optimize the ventilation management of elderly patients undergoing painless transesophageal echocardiography.

Objective:To explore the current status of surgery for portal hypertension to grasp current status and future development of surgery in China.Methods:This study is jointly sponsored by China Hepatobiliary & Pancreatic Specialist Alliance & Portal Hypertension Alliance in China (CHESS).Comprehensive surveying is conducted for basic domestic situations of surgery for portal hypertension, including case load, surgical approaches, management of postoperative complications, primary effects, existing confusion and obstacles, liver transplantation(LT), laparoscopic procedures and transjugular intrahepatic portosystemic shunt(TIPS), etc.Results:A total of 8 512 cases of portal hypertension surgery are performed at 378 hospitals nationwide in 2021.Splenectomy plus devascularization predominated(53.0%)and laparoscopy accounted for 76.1%.Primary goal is preventing rebleeding(67.0%) and 72.8% of hospitals used preventive anticoagulants after conventional surgery.And 80.7% of teams believe that the formation of postoperative portal vein thrombosis is a surgical dilemma and 65.3% of hospitals practiced both laparoscopy and TIPS.The major reasons for patients with portal hypertension not receiving LT are due to a lack of qualifications for LT(69.3%)and economic factors(69.0%).Conclusions:Surgery is an integral part of management of portal hypertension in China.However, it is imperative to further standardize the grasp of surgical indications, the handling of surgical operation and the management of postoperative complications.Moreover, prospective, multi-center randomized controlled clinical studies should be performed.

Objective:To explore the efficacy of digital and 3D printing technologies on design of superficial iliac circumflex artery flap for coverage the donor site of anterolateral thigh flap(ALTF).Methods:Clinical data of 8 patients were studied retrospectively for treatment of soft tissue defects of hand in the Department of Hand Surgery, Wuxi NO.9 People's Hospital Affiliated to Soochow University, from April 2017 to October 2021. The patients were 6 males and 2 females, aged from 29 to 59 years(mean, 45.8 years). Cause of injury: 3 patients were crushed, 2 by hot pressing, and 3 by machine strangulation. Site of injury included: 5 cases were dorsal hand defects and 3 cases were palm defects. All the wounds were contaminated to varying degrees with soft tissue defects. The areas of soft tissue defect ranged from 11 cm×10 cm to 22 cm×14 cm. Four patients had combined injuries of open fracture of metacarpals and phalanges and 3 with tendon defects. All wounds were repaired by free ALTF transplantation. And the donor sites in the thigh were repaired by superficial iliac circumflex artery flaps. The secondary wounds caused by flap harvesting on abdominal wall were closed directly. The targeted perforator vessels were detected preoperatively by CTA combined with CDU. 3D printed models of the affected hand were obtained before operation for individualised repairs according to the shape and area of the wounds. After the operation, all patients entered scheduled follow-ups at the outpatient clinic and via internet by observing the flap shape and testing the recovery of sensory and movement of adjacent joint.Results:The shapes and sizes of the wounds and the flaps were found basically in accordance with those in the preoperative simulative designs. All flaps in 8 patients survived and the wounds healed completely. All patients entered follow-ups for 8 to 24(average, 17.5) months. The donor thighs presented good appearance and colour, pliability without bloating. The range of motion of the hips and knees was not affected. Only linear scars remained in the abdominal donor sites, with natural colour and appearance.Conclusion:Digital and 3D printing technologies in preoperative design of flaps can help to locate the perforator vessels intraoperatively and guide the individualised design of the flaps with improved operation efficiency and satisfactory appearance of the flaps.

Objective:To investigate the changes in adaptive phenotypes of Yersinia pestis ( Yp) during successive passages in macrophages. Methods:A Yp strain of 201-MI was induced by 50 successive passages of Yp 201 strain in Raw264.7 cells. Phenotypic characteristics of 201 and 201-MI strains were compared by analyzing their survival rates in macrophages, growth curves, biofilm formation abilities, acid and hydrogen peroxide-stress tolerance, and virulence to mammal cells (Raw264.7 and HeLa cells) and mice. Results:Comparing with 201 strain, 201-MI strain showed various phenotypic changes, including higher survival rate in Raw264.7 cells, faster growth in iron-deficient medium, higher tolerance to acid and hydrogen peroxide, decreased biofilm formation ability, and less damages to Raw264.7 and HeLa cells. More-over, 201-MI strain showed decreased virulence to mice in both subcutaneous and intraperitoneal challenges. Preliminary comparative genomics analysis revealed some indel and nonsense mutations in 201-MI strain, which might account for its phenotype changes.Conclusions:After successive passages in macrophages, Yp showed some phenotypic changes, which might reflect its adaptive evolution under the pressure of macrophages. Detailed multi-omics analysis would be of great help to understand the underlying genetic mechanisms of these changes, and the related Yp-macrophage interaction processes as well.

Objective:To investigate the incidence and influencing factors of parastomal hernia in patients with permanent colostomy.Methods:The retrospective cohort study was conduc-ted. The clinicopathological data of 72 patients with permanent colostomy in the Beijing Friendship Hospital of Capital Medical University from January 2016 to June 2020 were collected. There were 50 males and 22 females, aged (66±12)years. Observations indicators: (1) follow-up; (2) analysis of factors affecting the incidence of parastomal hernia; (3) comparison of the incidence of parastomal hernia in patients with different age. Follow-up was conducted using outpatient examination. Patients were followed up once every 12 months after surgery to detect the incidence of parastomal hernia up to September 2021. Measurement data with normal distribution were represented as Mean± SD, and comparison between groups was conducted using the t test. Measurement data with skewed distribution were represented as M(range). Count data were expressed as absolute numbers and percentages, and comparison between groups was conducted using the chi-square test. Univariate analysis was conducted using the corresponding statistical methods based on data type. Multivariate analysis was conducted using the Logistic regression model. Kaplan-Meier method was used to draw the parastomal hernia occurrence curve and calculate the incidence rate of parastomal hernia and Log-rank test was used to analyze the incidence of parastomal hernia. Results:(1) Follow-up. All 72 patients were followed up for 23(range, 12?76)months. During the follow-up, there were 31 patients developed parastomal hernia, with the incidence as 20.8%(15/72), 36.1%(26/72) and 43.1%(31/72) at postoperative 1 year, postoperative 2 year and postoperative 5 year, respectively. Of the 31 patients with parastomal hernia, there were 21 cases of type Ⅰ, 3 cases of type Ⅱ and 7 cases of type Ⅲ. Patients with parastomal hernia recovered with conservative treatment. (2) Analysis of factors affecting the incidence of parastomal hernia. Results of univariate analysis showed that age, subcutaneous fat thickness and rectus abdominis thickness were related factors affecting the incidence of parastomal hernia ( χ2=7.98, t=?2.95, 2.02, P<0.05). Results of multivariate analysis showed that age, subcutaneous fat thickness and rectus abdominis thickness were independent factors affecting the incidence of parastomal hernia ( odds ratio=4.07, 3.19, 0.07, 95% confidence interval as 1.46?11.32, 1.43?7.09, 0.01?0.84, P<0.05). (3) Comparison of the incidence of parastomal hernia in patients with different age. Of the 72 patients, there were 37 cases with age <65 years and 35 cases with age >65 years. Of the 31 patients with parastomal hernia, there were 10 cases with age<65 years and all of them with type Ⅰ parastomal hernia, and the incidence of parastomal hernia in postoperative 1 year and postoperative 2 year was 13.5%(5/37) and 27.0%(10/37), respectively. There were 21 cases with age ≥65 years and cases with type Ⅰ, type Ⅱ and type Ⅲ parastomal hernia were 11, 3 and 7, respectively. The postoperative 1 year and postoperative 2 year incidence of parastomal hernia in the 21 cases was 28.6%(10/35) and 45.7%(16/35), respectively. There was a significant difference in the incidence of parastomal hernia between patients<65 years and ≥65 years ( χ2=9.28, P<0.05). Conclusion:Age, subcutaneous fat thickness and rectus abdominis thickness are independent factors affecting the incidence of parastomal hernia.

Objective:To evaluate the prognostic value of pretreatment systemic immune-inflammation index (SII) and lactate dehydrogenase (LDH) in non-metastatic nasopharyngeal carcinoma (NPC).Methods:We retrospectively collected the data of 839 patients with non-metastatic NPC from National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital and Sun Yat-sen University Cancer Center between January 2007 and October 2015. All patients received intensity modulated radiation based treatment. Optimal cutoff value of SII and LDH were determined by X-title software. The association between SII, LDH and clinical prognosis of non-metastatic NPC patients were analyzed. Kaplan-Meier method was used for survival analysis, and Log rank test was used for comparison of survival rates between groups. Propensity score matching (PSM) analysis was carried out to minimize the effects of confounding factors. The risk stratification model of prognosis by combining N stage, SII and LDH was constructed to compare the prognosis of patients in high risk group, middle risk group and low risk group, and the receiver operating characteristic (ROC) curve analysis was used to evaluate its prognostic value.Results:The optimal cutoff value of SII is 447.2×10 9/L for predicting the 5-year overall survival (OS) of NPC patients, and the best cutoff value of LDH is 198.9 U/L. The proportion of patients with stage T3-4 and stage III-IVB in high SII group was higher than that in low SII group ( P<0.001). Multivariate Cox regression analysis showed that N stage, SII and LDH were independent factors of OS, progression-free survival (PFS) and distant metastasis-free survival (DMFS) of NPC patients (N stage, HR=1.705, 95% CI: 1.247-2.332; HR=1.755, 95% CI: 1.342-2.295; HR=2.161, 95% CI: 1.515-3.082. SII, HR=1.525, 95% CI: 1.097-2.119; HR=1.518, 95% CI: 1.150-2.004; HR=1.837, 95% CI: 1.272-2.653. LDH, HR=2.041, 95% CI: 1.403-2.968; HR=1.725, 95% CI: 1.233-2.414; HR=2.492, 95% CI: 1.690-3.672, respectively). After PSM, SII was still an independent prognostic factor of OS, PFS and DMFS in NPC patients ( HR=1.52, 95% CI: 1.09-2.12; HR=1.52, 95% CI: 1.15-2.00; HR=1.82, 95% CI: 1.26-2.63, respectively). Combined with N 2-3 stage, SII (>447.2×10 9/L), and LDH (>198.9 U/L), patients were divided into high-(3 risk factors), intermediate- (2 risk factors) and low-risk (0-1 risk factors) groups. The 5-year OS rates of patients in low-, intermediate- and high-risk groups were 86.1%, 79.8% and 41.2% respectively, the 5-year PFS rates were 80.7%, 70.2% and 33.9% respectively, and the 5-year DMFS rates were 88.9%, 79.2% and 47.5% respectively. There were significant differences in OS, PFS and DMFS among these three groups ( P<0.001). Distant metastasis was the main failure pattern in low-, intermediate- and high-risk groups, and the highest rate of distant metastasis was 83.3% (15/31) in high-risk group. ROC curve of the risk stratification model for predicting 5-year OS of NPC patients is 0.610, which is higher than TNM stage (0.609), SII (0.574) and LDH (0.558). Conclusions:Pretreatment SII and LDH are significantly correlated with the prognosis of patients with non-metastatic NPC. The combination of SII, LDH and N stage can stratify the prognostic risk of NPC patients. The risk stratification model can enhance the accuracy of prognosis.

Objective:To evaluate the prognostic value of pretreatment systemic immune-inflammation index (SII) and lactate dehydrogenase (LDH) in non-metastatic nasopharyngeal carcinoma (NPC).Methods:We retrospectively collected the data of 839 patients with non-metastatic NPC from National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital and Sun Yat-sen University Cancer Center between January 2007 and October 2015. All patients received intensity modulated radiation based treatment. Optimal cutoff value of SII and LDH were determined by X-title software. The association between SII, LDH and clinical prognosis of non-metastatic NPC patients were analyzed. Kaplan-Meier method was used for survival analysis, and Log rank test was used for comparison of survival rates between groups. Propensity score matching (PSM) analysis was carried out to minimize the effects of confounding factors. The risk stratification model of prognosis by combining N stage, SII and LDH was constructed to compare the prognosis of patients in high risk group, middle risk group and low risk group, and the receiver operating characteristic (ROC) curve analysis was used to evaluate its prognostic value.Results:The optimal cutoff value of SII is 447.2×10 9/L for predicting the 5-year overall survival (OS) of NPC patients, and the best cutoff value of LDH is 198.9 U/L. The proportion of patients with stage T3-4 and stage III-IVB in high SII group was higher than that in low SII group ( P<0.001). Multivariate Cox regression analysis showed that N stage, SII and LDH were independent factors of OS, progression-free survival (PFS) and distant metastasis-free survival (DMFS) of NPC patients (N stage, HR=1.705, 95% CI: 1.247-2.332; HR=1.755, 95% CI: 1.342-2.295; HR=2.161, 95% CI: 1.515-3.082. SII, HR=1.525, 95% CI: 1.097-2.119; HR=1.518, 95% CI: 1.150-2.004; HR=1.837, 95% CI: 1.272-2.653. LDH, HR=2.041, 95% CI: 1.403-2.968; HR=1.725, 95% CI: 1.233-2.414; HR=2.492, 95% CI: 1.690-3.672, respectively). After PSM, SII was still an independent prognostic factor of OS, PFS and DMFS in NPC patients ( HR=1.52, 95% CI: 1.09-2.12; HR=1.52, 95% CI: 1.15-2.00; HR=1.82, 95% CI: 1.26-2.63, respectively). Combined with N 2-3 stage, SII (>447.2×10 9/L), and LDH (>198.9 U/L), patients were divided into high-(3 risk factors), intermediate- (2 risk factors) and low-risk (0-1 risk factors) groups. The 5-year OS rates of patients in low-, intermediate- and high-risk groups were 86.1%, 79.8% and 41.2% respectively, the 5-year PFS rates were 80.7%, 70.2% and 33.9% respectively, and the 5-year DMFS rates were 88.9%, 79.2% and 47.5% respectively. There were significant differences in OS, PFS and DMFS among these three groups ( P<0.001). Distant metastasis was the main failure pattern in low-, intermediate- and high-risk groups, and the highest rate of distant metastasis was 83.3% (15/31) in high-risk group. ROC curve of the risk stratification model for predicting 5-year OS of NPC patients is 0.610, which is higher than TNM stage (0.609), SII (0.574) and LDH (0.558). Conclusions:Pretreatment SII and LDH are significantly correlated with the prognosis of patients with non-metastatic NPC. The combination of SII, LDH and N stage can stratify the prognostic risk of NPC patients. The risk stratification model can enhance the accuracy of prognosis.