Categories
Nevin Manimala Statistics

Pure titanium denture large-span frameworks additively manufactured with selective laser melting

Zhonghua Kou Qiang Yi Xue Za Zhi. 2021 Jul 9;56(7):646-651. doi: 10.3760/cma.j.cn112144-20210405-00162.

ABSTRACT

Objective: To investigate the accuracy of pure titanium and cobalt-chromium alloy frameworks fabricated using the additive manufacturing (AM) of selective laser melting technology (SLM) for the mandibular implant-supported fixed prostheses and the maxillary removable partial denture (RPD), and to provide a reference for clinical application of SLM pure titanium frameworks. Methods: One edentulous mandibular model with implants and screw fixed abutments at bilateral canines and the first molars was selected and used as the mandibular full arch implant-supported model. At the same time, a Kennedy class Ⅰ maxillary dentition defect model was selected. The digital models were obtained by scanning the dental models, and the metal frameworks of the mandibular full arch implant-supported denture and the maxillary RPD (design model) were designed using the 3 Shape software. Meanwhile, 12 mandibular frameworks in the cobalt-chromium alloy and the pure titanium (6 in each group were treated with heat treatment, while the other 6 were not treated), and 7 maxillary frameworks in the cobalt-chromium alloy and the pure titanium were respectively made by SLM with the improved dual-laser metal printer. The axial direction of the printing powder accumulation was taken as the Z-axis. During the design process, the software (3Shape Dental System 2018) automatically generated the X-axis and Y-axis, X axis was the sagittal axis of the dental model and Y axis was the coronal axis of the dental model. The deviation of the interface center of the abutment of the digital model of the mandibular frameworks from the design model in the X, Y and Z axes was analyzed. As for the trueness of the mandibular framework, the larger the deviation data was, the worse the trueness was. The deviation of the whole maxillary framework and 7 measuring points (palatal plate center point and bilateral occlusal rests, I bars, proximal plates) were analyzed. The fitness of the whole maxillary framework to the design model was expressed by root mean square (RMS) of the deviation data, and the fitness of measuring points was expressed by the mean±standard deviation of the data. The trueness differences of each group before and after heat treatment of the mandibular framework and the fitness of the maxillary framework were compared. Results: The cobalt-chromium alloy frameworks showed lower trueness on the X, Y, Z-axes [(96.3±12.1), (86.3±11.4), (61.2±13.2) μm] than did the pure Ti frameworks [(82.3±11.2), (72.2±10.2), (51.2±11.6) μm] by SLM, and the heat treatment could reduce the discrepancy between the SLM frameworks and STL models, for pure titanium frameworks [(62.4±11.3), (55.2±13.2), (41.3±10.8) μm] and for cobalt-chromium alloy [(84.5±10.5), (72.3±11.2), (54.2±11.6) μm]. For the thin RPD major frameworks, pure titanium had better fitness [(121.3±17.0) μm] than cobalt-chromium alloy [(174.0±18.3) μm] by SLM, and the difference was statistically significant (P<0.05). Conclusions: Pure titanium frameworks fabricated by SLM additive manufacturing technology exhibited better fitness and trueness than did the Co-Cr frameworks after heat treatment respectively, and this satisfied the requirements of implant-supported fixed prostheses and RPD major metal frameworks.

PMID:34275219 | DOI:10.3760/cma.j.cn112144-20210405-00162

Categories
Nevin Manimala Statistics

Quantitative evaluation of printing accuracy of multi-color and multi-hardness three-dimensional printing dental model with photopolymer jetting

Zhonghua Kou Qiang Yi Xue Za Zhi. 2021 Jul 9;56(7):652-658. doi: 10.3760/cma.j.cn112144-20210315-00120.

ABSTRACT

Objective: To quantitatively evaluate the accuracy of multi-color and multi-hardness dental models printed by using the photopolymer jetting (PJ) technology, and to provide protocol for the clinical application. Methods: A maxillary partially edentulous (Kennedy class Ⅱ subclass 1) standard digital model obtained through scanning and processing was selected as reference data. Five monochromatic DLP (digital light processing) models with single hardness were printed by printer DLP-800d based on DLP technology (DLP group), and five multi-color and multi-hardness PJ models were printed by printer J300Plus based on PJ technology (PJ group). Scan the printed model and register the scanning data to the reference data in Geomagic Studio 2013 software. The three-dimensional (3D) deviations of the whole and each area, including residual dentition, abutments adjacent to the edentulous area, gingiva, gingiva in the distal-extended edentulous area, gingiva in other edentulous areas, gingiva supporting the removable partial denture (RPD), were calculated and represented by the root mean square error (RMS) value. The smaller the RMS value was, the higher the trueness of printing was. The scanning data of the five models in the same group were registered in pairs to calculate the 3D deviation. The smaller the RMS value was, the higher the precision of printing was. The threshold of clinical acceptability was 200 μm. Statistical analysis was performed to compare the difference of trueness and precision between the two groups. Results: The overall trueness of the DLP group [57.70 (2.10) μm] was significantly better than that of the PJ group [71.00 (7.70) μm]. The overall precision of the DLP group [15.20 (5.05) μm] was significantly better than that of the PJ group [37.55 (15.55) μm]. The overall trueness and precision of both groups were within the clinically acceptable range. Conclusions: The domestic PJ printer used in this study can print multi-color and multi-hardness dental models with good trueness and precision, which can provide integrated 3D printing technology support for realizing the simulation of regional hardness differentiation between soft and hard tissues of dental models.

PMID:34275220 | DOI:10.3760/cma.j.cn112144-20210315-00120

Categories
Nevin Manimala Statistics

Deep learning-based dental plaque detection on permanent teeth and the influenced factors

Zhonghua Kou Qiang Yi Xue Za Zhi. 2021 Jul 9;56(7):665-671. doi: 10.3760/cma.j.cn112144-20201014-00526.

ABSTRACT

Objective: To develop an artificial intelligence system for detecting dental plaque on permanent teeth and find the influenced factors. Methods: Photos of the labial or buccal surfaces of the permanent teeth were taken by using an intraoral camera (1 280×960 pixels; TPC Ligang, Shenzhen, China) before and after applying the plaque-disclosing agent (Cimedical, Japan) in 25 volunteers [12 males, 13 femals, aged (23±3) years] recruided in accordance with the inclusion criteria from the students of Peking University School of Stomatology from October 2018 to June 2019. A total of 549 groups of photos were captured and then divided into a training dataset containing 440 groups of photos and a test dataset including 109 groups of photos. The scopes of teeth and dental plaque on photos were labeled using LabelMe (Windows 3.2.1, MIT, U S A). A DeepLab based deep learning system was designed for the intelligent detection of dental plaque on permanent teeth. The mean intersection over union (MIoU) was employed to indicate the detection accuracy. Matlab (Windows R2017a, MathWorks, U S A) was used to extract the plaque edge line of 109 groups of photos and to calculate the number of pixels for the measurement of the complexity of the plaque edge line. The percentage of dental plaque area was calculated. Multivariate linear regression was used to explore whether tooth site, plaque percentage, number of plaque edge line pixels and lens light spot location would influence the detection accuracy, of which P<0.05 was considered statistically significant. Results: The MIoU of the permanent tooth model was 0.700±0.191 when 440 photos were used for training and 109 photos were used for testing. In the regression model of significance test (P<0.05), the percentage of plaque and the number of pixels on the edge of plaque had significant influence on the accuracy of dental plaque detection. The standardized coefficient of the number of pixels of the plaque edge line is -0.289, and the standardized coefficient of the percentage of plaque is -0.551. Conclusions: In the present study, an artificial intelligence system was built to detect dental plaque area on tooth photos collected by family intraoral camera. The system showed the ability to detect the dental plaque of permanent teeth. The more complex the marginal line of dental plaque and higher the percentage of dental plaque are, the lower the accuracy of plaque recognition is.

PMID:34275222 | DOI:10.3760/cma.j.cn112144-20201014-00526

Categories
Nevin Manimala Statistics

Comparison between periapical radiography and cone beam computed tomography for the diagnosis of anterior maxillary trauma in children and adolescents

Dent Traumatol. 2021 Jul 18. doi: 10.1111/edt.12706. Online ahead of print.

ABSTRACT

BACKGROUND/AIMS: Under-estimating the damage caused by trauma to the dental structures may delay treatment. Timely and accurate diagnosis remains challenging in clinical practice. Radiography is an important modality for the diagnosis of traumatic injuries. The aim of this study was to compare the efficacy of periapical radiography and cone beam computed tomography for the diagnosis of trauma to the anterior maxillary dentoalveolar region in children and adolescents.

MATERIAL AND METHODS: Images of patients who underwent both periapical radiography and cone beam computed tomography simultaneously because of trauma to the anterior maxillary region between January 2016 and January 2020 were analyzed retrospectively. Pairwise comparison between the receiver operating characteristic curves was performed to statistically compare the two methods for the diagnosis of crown fractures, root fractures, alveolar bone fractures and luxations, tooth resorption, and periapical radiolucencies.

RESULTS: A total of 190 patients met the inclusion criteria. There were 120 (63.2%) males and 70 (36.8%) females, with a mean age of 11.1 years (range: 6-17 years). A crown fracture was observed in 144 teeth, while a root fracture was observed in 71 teeth. Alveolar fracture and luxation were observed in 44 incisors. During follow-up, tooth resorption and periapical radiolucencies were observed in 25 and 33 teeth, respectively. Pairwise receiver operating characteristic curve analysis revealed that cone beam computed tomography was significantly superior to periapical radiography for the diagnosis of root fractures, alveolar fractures and luxations, and tooth resorption (p < .05). However, no significant differences were found for the diagnosis of crown fractures and periapical radiolucencies (p > .05).

CONCLUSIONS: Cone beam computed tomography in the low-dose mode was better for diagnosing root and bone fractures and resorption, but no different to periapical radiographs for crown fractures and periapical radiolucencies in pediatric patients.

PMID:34275178 | DOI:10.1111/edt.12706

Categories
Nevin Manimala Statistics

Clinical evaluation of air-polishing with erythritol powder followed by ultrasonic calculus removal versus conventional ultrasonic debridement and rubber-cup polishing for the treatment of gingivitis: a split-mouth randomized controlled clinical trial

Int J Dent Hyg. 2021 Jul 18. doi: 10.1111/idh.12537. Online ahead of print.

ABSTRACT

OBJECTIVES: To evaluate the clinical efficacy in the short-term resolution of gingivitis of a novel protocol involving full-mouth erythritol-powder air-polishing followed by ultrasonic calculus removal.

METHODS: 41 healthy patients completed the study. Following a split-mouth design, quadrants 1-4 and 2-3 were randomly allocated to receive air-polishing followed by ultrasonic calculus removal (A+US) or traditional full-mouth ultrasonic debridement followed by polishing with a rubber cup and prophylactic paste (US+P). Bleeding on probing (BoP) and Plaque Index (PI) were collected at baseline and 2 and 4 weeks. Moreover, the Residual Plaque Area (RPA), treatment time and patient comfort/satisfaction were evaluated at the end of the treatment.

RESULTS: Both treatments showed a significant reduction of BoP and PI. At 4 weeks A+US seems to reach a statistically significant lower BoP (8.7% [6.9;10.9] vs 11.6%[9.3;14.4], p<0.0001) and PI (10.7% [8.9;13.0] vs 12.3% [10.2;14.9], p= 0.033). Moreover, A+US treatment time lasted on average 9,2% less than US+P (p<0.0001), and was the preferred treatment for a significantly higher number of patients (73.2% vs 17.1%, p= 0.0001).

CONCLUSION: The A+US protocol is suitable for the short-term resolution of plaque-induced gingivitis.

PMID:34275193 | DOI:10.1111/idh.12537

Categories
Nevin Manimala Statistics

Patient specific prediction of temporal lobe epilepsy surgical outcomes

Epilepsia. 2021 Jul 18. doi: 10.1111/epi.17002. Online ahead of print.

ABSTRACT

OBJECTIVE: Drug-resistant temporal lobe epilepsy (TLE) is the most common type of epilepsy for which patients undergo surgery. Despite the best clinical judgment and currently available prediction algorithms, surgical outcomes remain variable. We aimed to build and to evaluate the performance of multidimensional Bayesian network classifiers (MBCs), a type of probabilistic graphical model, at predicting probability of seizure freedom after TLE surgery.

METHODS: Clinical, neurophysiological, and imaging variables were collected from 231 TLE patients who underwent surgery at the University of California, San Francisco (UCSF) or the Montreal Neurological Institute (MNI) over a 15-year period. Postsurgical Engel outcomes at year 1 (Y1), Y2, and Y5 were analyzed as primary end points. We trained an MBC model on combined data sets from both institutions. Bootstrap bias corrected cross-validation (BBC-CV) was used to evaluate the performance of the models.

RESULTS: The MBC was compared with logistic regression and Cox proportional hazards according to the area under the receiver-operating characteristic curve (AUC). The MBC achieved an AUC of 0.67 at Y1, 0.72 at Y2, and 0.67 at Y5, which indicates modest performance yet superior to what has been reported in the state-of-the-art studies to date.

SIGNIFICANCE: The MBC can more precisely encode probabilistic relationships between predictors and class variables (Engel outcomes), achieving promising experimental results compared to other well-known statistical methods. Multisite application of the MBC could further optimize its classification accuracy with prospective data sets. Online access to the MBC is provided, paving the way for its use as an adjunct clinical tool in aiding pre-operative TLE surgical counseling.

PMID:34275140 | DOI:10.1111/epi.17002

Categories
Nevin Manimala Statistics

Systematic review with meta-analysis: neoplasia detection rate and post-endoscopy Barrett’s neoplasia in Barrett’s oesophagus

Aliment Pharmacol Ther. 2021 Jul 18. doi: 10.1111/apt.16531. Online ahead of print.

ABSTRACT

BACKGROUND: Neoplasia detection rate, the proportion of Barrett’s oesophagus patients with high-grade dysplasia or oesophageal adenocarcinoma detected at index surveillance endoscopy has been proposed as a quality metric. However, the correlation between neoplasia detection rate and a clinically relevant outcome like post-endoscopy Barrett’s neoplasia remains unknown. Post-endoscopy Barrett’s neoplasia refers to the rate of high-grade dysplasia or oesophageal adenocarcinoma on repeat endoscopy within one year of an index screening examination revealing non-dysplastic Barrett’s oesophagus or low-grade dysplasia.

AIM: To assess correlation between neoplasia detection rate and post-endoscopy Barrett’s neoplasia.

METHODS: We performed a systematic search of multiple databases from date of inception to June 2021 to identify cohort studies reporting both neoplasia detection rate and post-endoscopy Barrett’s neoplasia. Data from each study were pooled using a random effects model, and their correlation assessed using meta-regression. Heterogeneity was assessed and a priori planned subgroup analyses were conducted.

RESULTS: Ten studies with 27 894 patients with Barrett’s oesophagus were included. The pooled neoplasia detection rate and post-endoscopy Barrett’s neoplasia were 5.0% (95% CI: 3.4%-7.1%, I2 = 97%) and 19.6% (95% CI: 10.1%-34.7%, I2 = 96%), respectively. Meta-regression revealed a statistically significant inverse relationship between the two variables (coefficient -3.50, 95% CI: -4.63 to -2.37, P < 0.01). With every 1% increase of neoplasia detection rate, post-endoscopy Barrett’s neoplasia decreased by 3.50%. Heterogeneity was high despite adjusting for study quality and performing several subgroup analyses.

CONCLUSION: We observed a statistically significant inverse correlation between neoplasia detection rate and post-endoscopy Barrett’s neoplasia. Additional studies are needed to further validate this correlation.

PMID:34275161 | DOI:10.1111/apt.16531

Categories
Nevin Manimala Statistics

Development of machine learning algorithms to predict achievement of minimal clinically important difference for the KOOS-PS following total knee arthroplasty

J Orthop Res. 2021 Jul 18. doi: 10.1002/jor.25125. Online ahead of print.

ABSTRACT

As cost-effective measures become increasingly implemented in the US healthcare system, changes in patient-reported outcome measure (PROM) scores can be utilized to indicate patient satisfaction following procedures including total knee arthroplasty (TKA). The primary aim of this study was to develop and evaluate machine learning algorithms to predict achievement of the minimal clinically important difference (MCID) for the Knee Injury and Osteoarthritis Outcome Score-Physical Function Short Form (KOOS-PS) at 1-year following TKA. A retrospective review of primary TKA patients between 2016 and 2018 was performed. Variables considered for prediction included demographics and preoperative PROMs. The KOOS-PS MCID was calculated via a distribution-based method. Five machine learning algorithms were developed and tested by discrimination, calibration, Brier score, and decision curve analysis. Among the 744 patients who met the inclusion criteria, 385 (72.8%) patients achieved the MCID. The elastic-net penalized logistic regression model was selected as the best performing model (c-statistic 0.77, calibration intercept -0.02, calibration slope 1.15, and Brier score 0.14). The most important variables for MCID achievement were preoperative KOOS-PS score, preoperative VAS Pain, preoperative opioid use, preoperative PROMIS global mental health score, age, and sex. Algorithms were incorporated into an open-access digital application available at https://sorg-apps.shinyapps.io/tka_koos_mcid/. This study is the first to predict the probability of achieving the KOOS-PS MCID following TKA using a machine learning-based approach. The results were used to develop a clinical decision aid based on commonly collected predictive variables to preoperatively predict an individual patient’s likelihood of attaining an acceptable outcome following TKA.

PMID:34275163 | DOI:10.1002/jor.25125

Categories
Nevin Manimala Statistics

Safety and Effectiveness Analysis of Dolutegravir in Patients with HIV-1: Interim Report of Post-Marketing Surveillance in Japan

Adv Ther. 2021 Jul 18. doi: 10.1007/s12325-021-01842-3. Online ahead of print.

ABSTRACT

INTRODUCTION: Dolutegravir (DTG), a novel HIV-integrase strand transfer inhibitor (INSTI), is usually used with multiple antiretrovirals (ARVs) for treatment of HIV. DTG is now approved as Tivicay tablets in over 120 countries and Triumeq combination tablets (DTG/abacavir [ABC]/lamivudine [3TC]) in over 90 countries. In Japan, these formulations have been marketed since 2014 and 2015. The post-marketing prospective surveillance has been conducted as part of the HIV-Related Drug (HRD) cooperative survey aimed to collect actual drug use information in all of these DTG-treated patients in accordance with conditions for initial approvals.

METHODS: The survey has been conducted to evaluate long-term safety and effectiveness of DTG since 2014, for approximately 6 years. The safety was evaluated by incidence of adverse drug reactions (ADRs) and change in body weight. The effectiveness was evaluated by plasma HIV RNA copies/mL and peripheral CD4+ cell counts.

RESULTS: Of 2292 patients in 30 Japanese sites, 565 (24.65%) reported ADRs. The most common ADR was blood creatinine increased (4.28%). Incidence of ADRs was statistically significantly higher in patients with severe symptoms (Centers for Disease Control and Prevention [CDC] categories B and C) than those with category A, and in patients with comorbidities than those without comorbidities. Whereas incidence of ADRs was statistically significantly lower in antiretroviral therapy (ART)-experienced patients than that in ART-naïve patients. Incidence of ADRs related to suicide or self-injurious behavior was statistically significantly higher in patients with comorbidities of psychiatric disorders than those without comorbidities. The body weight tended to increase over time and those changes and percentage changes from baseline were greater in ART-naïve patients compared with ART-experienced patients. HIV RNA copies/mL and CD4+ cell counts showed favorable shifts from baseline in both ART-naïve and ART-experienced patients.

CONCLUSION: The results of the survey identified no new safety and effectiveness risks in Japanese patients with HIV/AIDS treated with DTG.

PMID:34275116 | DOI:10.1007/s12325-021-01842-3

Categories
Nevin Manimala Statistics

Assessment of the Benefits and Cost-Effectiveness of Population-Based Breast Cancer Screening in Urban China: A Model-Based Analysis

Int J Health Policy Manag. 2021 Jul 4. doi: 10.34172/ijhpm.2021.62. Online ahead of print.

ABSTRACT

BACKGROUND: To decrease the burden of breast cancer (BC), the Chinese government recently introduced biennial mammography screening for women aged 45-70 years. In this study, we assess the effectiveness and cost-effectiveness of implementing this programme in urban China using a micro-simulation model.

METHODS: The ‘Simulation Model on radiation Risk and breast cancer Screening’ (SiMRiSc) was applied, with parameters updated based on available data for the Chinese population. The base scenario was biennial mammography screening for women aged 45-70 years, and this was compared to a reference population with no screening. Seven alternative scenarios were then simulated by varying the screening intervals and participant ages. This analysis was conducted from a societal perspective. The discounted incremental cost-effectiveness ratio (ICER) was compared to a threshold of triple the gross domestic product (GDP) per life years gained (LYG), which was 30 785 USD/LYG. Univariate sensitivity analyses were conducted to evaluate model robustness. In addition, a budget impact analysis was performed by comparing biennial screening with no screening at a time horizon of 10 years.

RESULTS: Compared with no screening, the base scenario was cost-effective in urban China, giving a discounted average cost-effectiveness ratio (ACER) of 17 309 USD/LYG. The model was most sensitive to the cost of mammography per screen, followed by mean size of self-detected tumours, mammographic breast density and the cumulative lifetime risk of BC. The efficient frontier showed that at a threshold of 30 785 USD/LYG, the base scenario was the optimal scenario with a discounted ICER of 25 261 USD/LYG. Over 10 years, screening would incur a net cost of almost 38.1 million USD for a city with 1 million citizens.

CONCLUSION: Compared to no screening, biennial mammography screening for women aged from 45-70 is cost-effective in urban China.

PMID:34273933 | DOI:10.34172/ijhpm.2021.62