A CT-based technique to predict optimal projection for self-expanding TAVI in patients with different aortic valve anatomies

Background Optimal projection is essential for valve deployment during transcatheter aortic valve implantation (TAVI). The purpose of this study was to propose an approach to predict optimal projection in TAVI candidates with different aortic valve anatomies. Methods 331 patients undergoing self-expanding TAVI were included and the so-called non-coronary cusp (NCC)-parallel technique was utilized, which generated the predicted projection by connecting NCC commissures on the transverse plane on the pre-procedural computed tomography images. Results 37.8% of the study cohort were bicuspid aortic valve (BAV) patients. Around 80% of both NCC-parallel views and final views were in the right anterior oblique (RAO) and caudal (CAU) quadrant. There was less than 5° change required from the NCC-parallel view to the final implanted view in 79% of tricuspid aortic valve (TAV) patients but only in 27% (13/48) of type 0 BAV patients with coronary arteries originated from the different cusps. After excluding the above mentioned BAV patients, 62.3% (48/77) of BAV patients needed less than 5° change to achieve optimal projection and only in 8 patients, the angular change was larger than 10° in either left/right anterior oblique or cranial/caudal direction. Conclusions The NCC-parallel technique provides reliable prediction for optimal projection in self-expanding TAVI in all TAV and most BAV patients, with a vast majority of views in the RAO and CAU quadrant.

A Modified Tseng’s Method for Solving the Modified Variational Inclusion Problems and Its Applications

The goal of this study was to show how a modified variational inclusion problem can be solved based on Tseng’s method. In this study, we propose a modified Tseng’s method and increase the reliability of the proposed method. This method is to modify the relaxed inertial Tseng’s method by using certain conditions and the parallel technique. We also prove a weak convergence theorem under appropriate assumptions and some symmetry properties and then provide numerical experiments to demonstrate the convergence behavior of the proposed method. Moreover, the proposed method is used for image restoration technology, which takes a corrupt/noisy image and estimates the clean, original image. Finally, we show the signal-to-noise ratio (SNR) to guarantee image quality.

Measurement of the lower canine pulp chamber through periapical radiography for age estimation

Objectives: The principle of measurement using the TCI (Tooth Coronal Index) method is to compare the pulp chamber height with a person's chronological age based on the formation of secondary dentin. The purpose of this study is to estimate age based on pulp chamber height in lower canines using periapical radiographs with TCI measurement. Materials and Methods: This study is an observational analytic study using 42 samples of periapical radiographs with the parallel technique of the lower canines. Samples were measured for CH and CPCH heights to determine TCI values and then linear regression was made to determine their biological age. Finally, the difference between biological and chronological age is calculated to determine the approximate age. Results: The mean difference between chronological age and biological age was ± 5.05 years and an average biological age of 29.38 years. Conclusion: TCI method based on pulp chamber height in lower canines using periapical radiographs can be used to estimate age with the difference between chronological age and biological age of ±5.05 years.

A New 13-Level Switched-Capacitor Inverter with Reduced Device Count

This paper proposed a new voltage-boosting 13-level switched-capacitor (SC) cost-effective inverter. The proposed topology comprises fourteen transistors, three capacitors and a single DC source to produce a 13-level staircase waveform. The capacitor voltage balancing problem is inherently solved by the series/parallel technique. Structural description, working principle, calculation of optimum values of capacitance and modulation scheme are briefly described. The comparative analyses with the existing SC multilevel inverter (MLI) in terms of voltage gain, blocking voltage, total standing voltage (TSV), component per level factor and cost function illustrate the merits of the proposed topology. Further, simulation and experimental results at different loading conditions verify the feasibility of the proposed topology.

Clinical Efficacy of a Micro-locking Plate Vertical or Parallel Technique for Treatment of Dubberley B-type Capitellar Fractures

ObjectiveTo evaluate the clinical efficacy of micro-locking plate through vertical or parallel technique for treatment of Dubberley B-type capitellar fractures.MethodsA retrospective analysis was performed in 24 patients (seventeen males and seven females, with an average age of 44.9 years, range from 19 to 75 years) with capitellar fractures that were treated with micro-locking plate using vertical or parallel technique between January 2016 to January 2019. The inclusion criteria include closed capitellar fracture, anterior elbow joint movement normal before injury, recent capitellar fracture with times of injury within past 3 weeks. Fractures classified according to Dubberley included 4 cases of type IB, 8 cases of type IIB and 12 cases of type IIIB. Radiographic evaluation was performed. Surgery time, blood lose, range of motion of the elbow, forearm rotation and complications was recorded. Elbow joint function was evaluated by Mayo Elbow Performance Score (MEPS).ResultsThe mean follow-up period was 19.6 months (range, 12–36 months). The average clinical healing time for fractures was 11.2 ± 3.2 weeks (range, 8–20 weeks). Fracture united in all patients. Two patients showed slight delayed union, but union was achieved eventually. The mean time from injury to surgery was 6.3 ± 3.1 days (range, 2–15 days). The average surgical time was 68.1 ± 11.5 minutes(range, 50–90 minutes), and the mean blood loss was 75.2 ± 26.5 mL༈range, 40–120 mL). The mean range of flexion was 122.5°±10.5°༈range, 95°-140°). The mean range of extension was 8.5°±5.8°༈range, 0°-20°). The mean range of pronation was 79.7°±8.0°༈range, 65°-90°). The mean range of supination was 80.5°±7.1°༈range,60°-90°). The mean MEPS at final follow-up was 89.8 ± 9.0 (range, 60–100). Based on the MEPS, 18 (75%) patients had excellent, 5 (20.8%) patients had good and 1 (4.2%) patient had fair. None of the 24 patients suffered vascular or nerve injury. One patient showed superficial infection, which terated with surgical dressing.Conclusions The micro-locking plate accroding to vertical or parallel technique is an excellent method for Dubberley B-type capitellar fractures.

Peri-implantitis and Severity Level

Objectives Different diagnostic criteria were used for diagnosis of peri-implant diseases. The aim of this cross-sectional study was to explore prevalence of peri-implant diseases and subclassify peri-implantitis based on different levels of radiographic and clinical findings. Materials and Methods Two hundred patients having 655 dental implants were included in this study. In addition to clinical measurements, standard long-cone parallel technique was used to evaluate marginal bone level around implants. Following diagnosis of peri-implant diseases, peri-implantitis was further subclassified using a severity leveling in terms of marginal bone level and probing depth. Results Mean age of 200 subjects was 52.8 ± 12.2 years and 63% were females. In total, bleeding on probing was present in 93% and suppuration in 27% of implants. On subject basis, 2.5% were diagnosed as healthy, 28% with peri-implant mucositis (PM), and 69.5% with peri-implantitis, whereas on implant basis, 3.6% were healthy, 36% presented PM, and 60.4% peri-implantitis. Furthermore, when severity leveling was applied, peri-implantitis prevalence changed markedly and ranged from 14.5 to 31.0% at the subject level and from 10.0 to 22.0% at the implant level. Subgingival restoration margins were observed in 70.6% of patients for implants with PM and in 44% patients for implants with peri-implantitis. Most of the implants with peri-implantitis were with platform match (71.5%). Conclusions Applying different thresholds to the peri-implantitis definition yielded different prevalence rates ranging from 10 to 31%. As no established diagnostic criteria are being used today, results from clinical studies may not reflect the true disease prevalence.