A novel extraoral registration method for a dynamic navigation system guiding zygomatic implant placement in patients with maxillectomy defects

Zygomatic implants (ZIs) are used for the oral rehabilitation of patients with maxillectomy defects as an alternative to extensive bone grafting surgeries. New technologies such as computer-assisted navigation systems can improve the accuracy and safety of ZI placement. The intraoral anchorage of fiducial markers necessary for navigation registration is not possible in the case of a severe maxillary defect and lack of residual bone. This technical note presents a novel extraoral registration method for a dynamic navigation system guiding ZI placement in patients with maxillectomy defects. Titanium microscrews were inserted in the mastoid process, supraorbital ridge, and posterior zygomatic arch as registration markers. The mean fiducial registration error (FRE) was 0.53 ± 0.20 and the deviations between the planned and placed ZIs were 1.56 ± 0.54 mm (entry point), 1.87 ± 0.63 mm (exit point), and 2.52 ± 0.84° (angulation). The study results indicate that the placement of fiducial markers at extraoral sites can be used as a registration technique to overcome anatomical limitations in patients after maxillectomy, with a clinically acceptable registration accuracy.     

中成药欧盟注册分析

自2004年起，欧盟和美国分别发布了《传统植物药注册程序指令》和《植物药产品指南》，掀起了中药的新篇章，西方发达国家第一次在法律层面上认可中药作为药品的地位，现通过对欧盟植物药注册法规法律的探讨以及注册成功案例的分析，为我国中成药国际化注册提供一定参考。     

Mixed Reality Combined with Three‐Dimensional Printing Technology in Total Hip Arthroplasty: An Updated Review with a Preliminary Case Presentation

Three‐dimensional (3D) printing technology, virtual reality, and augmented reality technology have been used to help surgeons to complete complex total hip arthroplasty, while their respective shortcomings limit their further application. With the development of technology, mixed reality (MR) technology has been applied to improve the success rate of complicated hip arthroplasty because of its unique advantages. We presented a case of a 59‐year‐old man with an intertrochanteric fracture in the left femur, who had received a prior left hip fusion. After admission to our hospital, a left total hip arthroplasty was performed on the patient using a combination of MR technology and 3D printing technology. Before surgery, 3D reconstruction of a certain bony landmark exposed in the surgical area was first performed. Then a veneer part was designed according to the bony landmark and connected to a reference registration landmark outside the body through a connecting rod. After that, the series of parts were made into a holistic reference registration instrument using 3D printing technology, and the patient's data for bone and surrounding tissue, along with digital 3D information of the reference registration instrument, were imported into the head‐mounted display (HMD). During the operation, the disinfected reference registration instrument was installed on the selected bony landmark, and then the automatic real‐time registration was realized by HMD through recognizing the registration landmark on the reference registration instrument, whereby the patient's virtual bone and other anatomical structures were quickly and accurately superimposed on the real body of the patient. To the best of our knowledge, this is the first report to use MR combined with 3D printing technology in total hip arthroplasty.     

Predictive value of the coronary artery calcium score and advanced plaque characteristics: Post hoc analysis of the PREDICT registry

BackgroundWhether coronary plaque characteristics assessed in coronary computed tomography angiography (CCTA) in association with the coronary artery calcium score (CACS) have predictive value for coronary events is unclear. We aimed to examine the predictive value of the CACS and plaque characteristics for the occurrence of coronary events.MethodsAmong 2802 patients who were analyzed in the PREDICT registry, 2083 with suspected coronary artery disease (CAD) were studied using post hoc analysis. High-risk plaques were defined as having ≥2 adverse characteristics, such as low computed tomographic attenuation, positive remodeling, spotty calcification, and napkin-ring sign. An adjudicative composite of coronary events (cardiac death, nonfatal acute coronary syndrome, and coronary revascularization ≥3 months after indexed CCTA) were analyzed.ResultsSeventy-three (3.5%) patients had coronary events and 313 (15.0%) had high-risk plaques. Multivariate Cox proportional hazard analysis showed that high-risk plaques remained an independent predictor of coronary events (adjusted hazard ratio [HR] 1.95, 95% confidence interval [CI] 1.13–3.34, P ?= ?0.0154), as well as the log-transformed CACS (adjusted HR 1.24, 95% CI 1.11–1.39, P ?= ?0.0002) and the presence of obstructive stenosis (adjusted HR 5.63, 95% CI 3.22–10.12, P 0.0001). In subgroup analyses, high-risk plaques were independently predictive only in the low CACS class (<100).ConclusionThis study shows that assessment of adverse features by coronary plaque imaging independently predicts coronary events in patients with suspected CAD and a low CACS. Our findings suggest that the clinical value of high-risk plaques to CACS and stenosis assessment appears marginal.     

中成药上市后再评价的现状、挑战与展望

本文检索近十年中成药上市后进行的临床研究,尤其是在SCI杂志上发表的高质量临床研究,回顾目前注册中成药中进行上市后再评价现状及与国际接轨的情况。列出目前中成药进入国际市场存在的问题,并以FDA、加拿大及欧盟对于植物药及草药的注册要求来详细陈述,指出中成药上市后再评价的必要性及未来的发展趋势。     

Evaluation of two dental registration-splint techniques for surgical navigation in cranio-maxillofacial surgery

BackgroundSurgical navigation requires precise registration of the pre-operative image dataset to the patient in the operation theatre. Different marker-based and marker-free registration techniques are available, each of them with advantages and disadvantages regarding precision and clinical handling. In this model study, the precision of two dental splint techniques for marker-based registration is analyzed.Materials and methodsA synthetic full-size human skull was registered with its cone beam computed tomography dataset using (a) a dentally-mounted “rapid” occlusal splint with five titanium screws directly attached to the splint, (b) an “extender”, a dentally-mounted occlusal splint with similar fiducials fixed to an extension of the splint. The target registration error was measured for 170 landmarks distributed over the viscero- and neurocranium in 10 repeats per splint type using the Vector Vision² (BrainLAB AG, Heimstetten, Germany) navigation system. Statistical and graphical evaluations were performed per anatomical region.ResultsIn the periorbital region, the rapid splint, with an average deviation of 1.50 mm (SD = 0.439) showed greater accuracy than the extender with 1.76 mm (SD = 0.525). The viscerocranial results for both splints were similar (extender 1.84 mm, SD = 0.559, rapid occlusal splint 1.86 mm, SD = 0.686). In the cranial vault region, registration with the extender (2.33 mm, SD = 0.685) proved to be more precise than with the rapid splint (2.86 mm, SD = 0.929).ConclusionsDue to the more compact dimension of the rapid occlusal splint, errors close to the splint were smaller compared to the extender technique. The advantage of greater distances between the registration fiducials on the extender is particularly important in areas such as the orbital roof, the cranial vault, and the lateral skull base.     

Pro-equity immunization and health systems strengthening strategies in select Gavi-supported countries

BackgroundAchieving universal immunization coverage and reaching every child with life-saving vaccines will require the implementation of pro-equity immunization strategies, especially in poorer countries. Gavi-supported countries continue to implement and report strategies that aim to address implementation challenges and improve equity. This paper summarizes the first mapping of these strategies from country reports.MethodsThirteen Gavi-supported countries were purposively selected with emphasis on Gavi’s priority countries. Following a scoping of different documents submitted to Gavi by countries, 47 Gavi Joint Appraisals (JAs) for the period 2016–2019 from the 13 selected countries were included in the mapping. We used a consolidated framework synthesized from 16 different equity and health systems frameworks, which incorporated UNICEF’s coverage and equity assessment approach – an adaptation of the Tanahashi model. Using search terms, the mapping was conducted using a combination of manual search and the MAXQDA qualitative analysis tool. Pro-equity strategies meeting the inclusion criteria were identified and compiled in an Excel database, and then populated on a tableau visualization dashboard.ResultsIn total, 258 pro-equity strategies were implemented by the 13 sampled Gavi-supported countries between 2016 and 2019. The framework determinants of social norms, utilization, and management and coordination accounted for more than three-quarters of all pro-equity strategies implemented in these countries. The median number of strategies reported per country was 17. Afghanistan, Nigeria, and Uganda reported the highest number of strategies that we considered as pro-equity.ConclusionFindings from this mapping can be useful in addressing equity gaps, reaching partially immunized, and ‘zero-dose’ vaccinated children, and valuable resource for countries planning to implement pro-equity strategies, especially as immunization stakeholders reimagine immunization delivery in light of COVID-19, and as Gavi finalizes its fifth organizational strategy. Future efforts should seek to identify pro-equity strategies being implemented across additional countries, and to assess the extent to which these strategies have improved immunization coverage and equity.     

Image Fusion of Real-Time Ultrasonography with Computed Tomography: Factors Affecting the Registration Error and Motion of Focal Hepatic Lesions

Factors affecting the registration error (RE) and motion of focal hepatic lesions (FHLs) in image fusion of real-time ultrasonography (US) with computed tomography (CT) images were prospectively assessed by focusing on respiratory movement and FHL location. Real-time US and pre-acquired CT images at end-inspiration were fused with FHLs for 103 patients. Three-dimensional US data containing FHLs were obtained during end-inspiratory/expiratory phases. Multivariate analysis revealed that diaphragm motion (p < 0.001), chronic liver disease (p = 0.02) and the absolute difference in distance between the FHL and the central portal vein (CPV) during respiration (p = 0.03) were the independent factors that revealed the maximum effect on RE. In contrast, diaphragm motion (p < 0.001) and distance between the FHL and CPV at inspiration (p = 0.036) revealed the maximum effect on FHL motion. In conclusion, RE and FHL motion are affected by the degree of respiratory movement and the location of the FHL. Therefore, image fusion with CT images should be used with caution if the degree of respiratory motion is significant or if the FHL is located at the periphery of the liver.     

Treatment effect analysis of curettage for jaw cysts based on volumetric assessment and image registration

The study was conducted to develop a visual and intuitive quantitative evaluation method for maxillary cystic lesions after curettage. Mimics 16.0 and Geomagic Studio 2013 were used to form a precise reconstruction of the cystic lesion morphology of 60 cases; the average reduction rates and 95% confidence interval were calculated. Computed tomography (CT) registration was performed before and after surgery to observe morphology features of the bone regeneration of the cystic area. The average reduction rates (RR) of the cysts after curettage were (43.56 ± 16.79)%, (54.33 ± 17.15)% and (68.53 ± 15.99)% at 3 months, 6 months and 12 months after surgery, respectively. The average monthly reduction rates (MRR) were (12.07 ± 4.35)%, (8.16 ± 2.84)% and (5.35 ± 1.52)% at 3 months, 6 months and 12 months after surgery, respectively. Correlation analysis by comparing with each group showed that the effect of sex and age in the 3-month group and the initial size in the 12-month group on RR and MRR were statistically significant. Within the limitations of the study it seems that the chosen approach for quantitative evaluation of the therapeutic effect of curettage for jaw cystic lesions might facilitate visual and quantitative follow-up of cyst curettage and timely detection of recurrence.