Trueness of artificial teeth for CAD-CAM complete dentures fabricated with additive manufacturing implementing different denture base-tooth offset values: An in vitro study.

STATEMENT OF PROBLEM: Computer-aided design and computer-aided manufacturing (CAD-CAM) removable dentures have become popular. However, evaluations of the effect of denture base-tooth offset (DTO) values on the trueness of artificial teeth are lacking. PURPOSE: The purpose of this in vitro study was to digitally measure the trueness of the artificial teeth of CAD-CAM dentures fabricated with additive manufacturing using different DTO values and to determine the most accurate DTO value. MATERIAL AND METHODS: Seven study groups were formulated based on different DTO values, and 6 maxillary complete dentures were assigned to each group (n=42). A design software program was used to export the monoblock denture as control, the artificial teeth, and 7 different designs of denture bases with DTO values of 0.00, 0.01, 0.03, 0.05, 0.10, 0.15, and 0.20 mm. Denture bases were printed in denture base resin (Denture base RP; formlabs), artificial teeth were printed in tooth-shade resin (Denture teeth A2; formlabs), and both were then assembled and polymerized together. The dentures were scanned (InEos X5; Dentsply Sirona), scan data were imported in a measuring software program (GOM Inspect; GOM GmbH), and registration using local best fit was performed to align data. Color-coded maps for the surface comparison of each denture with the control denture scan were generated. Fitting center points were constructed for each artificial tooth, which were compared with their corresponding points on the data of the control scan. Multiple pairwise comparisons were performed after 1-way ANOVA to quantify and statistically evaluate the deviation values (α=.05). RESULTS: The 0.10-mm DTO group showed the lowest values when comparing artificial tooth deviations both individually and as types. On comparing the average deviations, statistically significant differences were identified among the 7 groups (P<.001). A nonstatistically significant difference was identified when the 0.10- and 0.05-mm DTO groups were compared. Lower deviation values were found in the premolars compared with the molars, in the incisors compared with the canines, and in posterior artificial teeth compared with anterior teeth. CONCLUSIONS: The 0.10-mm DTO value showed the highest trueness for the artificial teeth compared with the other DTO values tested in this study. The 0.05-mm DTO value is an alternative to the 0.10-mm DTO value for CAD-CAM dentures constructed by additive manufacturing. Anterior teeth of a CAD-CAM denture showed higher deviation values compared with posterior teeth.

The Need for Protocol-Based Training in Delivering Bad News in Dentistry: A Cross-Sectional Survey Among Dental Professionals in Jeddah, Saudi Arabia.

AIM:  This study aimed to explore the awareness and utilization of protocols (e.g., the SPIKES protocol) for delivering bad news among dental professionals and the perceived need for such training. METHODS:  This study employed a cross-sectional design. A web-based self-administered questionnaire was distributed among dental students, general dentists, and dental specialists/consultants in Jeddah City through social media groups. The questionnaire included questions regarding the knowledge, attitudes, and practices of delivering bad news in dentistry and the use of the SPIKES protocol. Descriptive statistics and bivariate and multivariate analyses were performed to determine the research objectives. RESULTS:  Two hundred and twelve participants responded to the questionnaire, with an almost equal distribution between genders. Specialists/consultants and dental students comprised 87.8% of the respondents. Most respondents (70%) were unaware of any protocols for delivering bad news, and approximately 89% were unaware of the SPIKES protocol. Only 7% reported using the SPIKES protocol to deliver bad news. The bivariate analysis revealed two significant associations. The first association indicated a variation in awareness based on professional status, and the second suggested that experience in delivering bad news affected perceptions of the importance of protocol-based training. Logistic regression models revealed that specialist/consultant status was significantly associated with decreased awareness of protocols (OR = 0.287, 95% CI 0.091-0.903) as compared to general dentists and that other variables, including sex and experience in delivering bad news, did not indicate a statistically significant effect. CONCLUSION:  Most dentists in Jeddah reported the need to be familiar with and practice delivering bad news in dentistry. They agreed that it would improve patients' acceptance of bad news if it were performed in a systematic and organized manner (e.g., the SPIKES protocol).

The Approach to Dental Caries Prevention in a Case of Agenesis of the Major Salivary Glands: A Case Report.

Xerostomia leads to great challenges for patients and dentists in managing and maintaining oral health due to the high risk of developing dental caries. We discuss a case of a 10-year-old male patient who presented with complaints of decayed teeth and difficulty chewing and swallowing food. He had bilateral congenital stenosis and stricture of lacrimal ducts and a family history of lacrimal gland agenesis and Hashimoto's disease. The diagnosis reached was agenesis of all major salivary glands confirmed by saliva testing and ultrasound examination of the glands. Comprehensive preventative, restorative, and maintenance protocols based on caries management by risk assessment (CAMBRA) were implemented, including fissure sealants, amalgam and composite resin restorations, professional and home-applied fluoride, chlorhexidine mouthwash, frequent water consumption, and two-monthly recalls. We were able to stabilize the patient's risk of dental caries for over three years. The implementation of stringent restorative, preventive, and maintenance protocols is key to improving and maintaining oral health in severe cases of xerostomia.

Artificial intelligence-based recurrence prediction outperforms classical histopathological methods in pulmonary adenocarcinoma biopsies.

INTRODUCTION: Between 10 and 50% of early-stage lung adenocarcinoma patients experience local or distant recurrence. Histological parameters such as a solid or micropapillary growth pattern are well-described risk factors for recurrence. However, not every patient presenting with such a pattern will develop recurrence. Designing a model which can more accurately predict recurrence on small biopsy samples can aid the stratification of patients for surgery, (neo-)adjuvant therapy, and follow-up. MATERIAL AND METHODS: In this study, a statistical model on biopsies fed with histological data from early and advanced-stage lung adenocarcinomas was developed to predict recurrence after surgical resection. Additionally, a convolutional neural network (CNN)-based artificial intelligence (AI) classification model, named AI-based Lung Adenocarcinoma Recurrence Predictor (AILARP), was trained to predict recurrence, with an ImageNet pre-trained EfficientNet that was fine-tuned on lung adenocarcinoma biopsies using transfer learning. Both models were validated using the same biopsy dataset to ensure that an accurate comparison was demonstrated. RESULTS: The statistical model had an accuracy of 0.49 for all patients when using histology data only. The AI classification model yielded a test accuracy of 0.70 and 0.82 and an area under the curve (AUC) of 0.74 and 0.87 on patch-wise and patient-wise hematoxylin and eosin (H&E) stained whole slide images (WSIs), respectively. CONCLUSION: AI classification outperformed the traditional clinical approach for recurrence prediction on biopsies by a fair margin. The AI classifier may stratify patients according to their recurrence risk, based only on small biopsies. This model warrants validation in a larger lung biopsy cohort.

Tribology of Coated 316L SS by Various Nanoparticles.

Background: Nanocoating of biomedical materials may be considered the most essential developing field recently, primarily directed at improving their tribological behaviors that enhance their performance and durability. In orthodontics, as in many medical fields, friction reduction (by nanocoatings) among different orthodontic components is considered a substantial milestone in the development of biomedical technology that reduces orthodontic treatment time. The objective of the current research was to explore the tribological behavior, namely, friction of nanocoated thin layer by tantalum (Ta), niobium (Nb), and vanadium (V) manufactured using plasma sputtering at 1, 2, and 3 hours on substrates made of 316L stainless steel (SS), which is thought to be one of the most popular alloys for stainless steel orthodontic archwires. The friction of coated 316L SS archwires coated with Ta, Nb, and V plasma sputtering is hardly mentioned in the literature as of yet. Results: An oscillating pin-on-plate tribological test using a computerized tribometer was performed by applying a load of 1 N for 20 minutes under the dry condition at room temperature (25°C) to understand their role in the tribological behavior of the bulk material. Ta and Nb were found to reduce the friction of their SS substrate significantly (45 and 55%, respectively), while V was found to deteriorate the friction of its substrate. Moreover, sputtering time had no substantial role in the friction reduction of coatings. Conclusions: Nanocoating of 316L SS bulk material by Nb and Ta with a 1-hour plasma sputtering time can enhance dramatically its tribological behavior. Higher coating hardness, smaller nanoparticle size, intermediate surface coating roughness, and lower surface binding energy of the coatings may play a vital role in friction reduction of the coated 316L SS corresponding to SS orthodontic archwires, predicting to enhance orthodontic treatment.

Clinical management and infection control protocols during the COVID-19 pandemic: An online survey.

BACKGROUND: SARS-CoV-2 (COVID-19) is considered a highly infectious and life threatening disease. OBJECTIVE: The present paper aims to evaluate various aspects of preventive measures and clinical management of the scheduled visits for orthodontic patients to the dental clinics during the outbreak of COVID-19, and to assess how orthodontists dealt with this challenge. METHODS: Orthodontists in private and public clinics were invited to fill a questionnaire that addressed infection control protocols and concerns about clinical management of patients in the clinics during the pandemic. Frequncies and percentages of the responses were obtained and compared using Chi-square tests. RESULTS: About 77% of those working in private clinics, and 63% of those working in private and governmental clinics performed room disinfection following each patient. In case of patients needing urgent management and have active infection, 56% of the participants provided care under high infection control measures; on the contrary, 64% provided symptomatic intervention including orthodontic wax, analgesics and sometimes mouthwash. CONCLUSION: The COVID-19 pandemic has had a negative impact on the orthodontic treatments. All pre-cautionary measures have to be made available in the clinic in order to minimize the spread of viral infection with continuous dental health care training.

Surface Characterization of Stainless Steel 316L Coated with Various Nanoparticle Types.

Background: Material tribology has widely expanded in scope and depth and is extended from the mechanical field to the biomedical field. The present study aimed to characterize the nanocoating of highly pure (99.9%) niobium (Nb), tantalum (Ta), and vanadium (V) deposited on 316L stainless steel (SS) substrates which considered the most widely used alloys in the manufacturing of SS orthodontic components. To date, the coating of SS orthodontic archwires with Nb, Ta, and V using a plasma sputtering method has never been reported. Nanodeposition was performed using a DC plasma sputtering system with three different sputtering times (1, 2, and 3 hours). Results: Structural and elemental analyses were conducted on the deposited coatings using XRD, FESEM, and EDS showing a unique phase of coating metals over their substrates with obvious homogeneous even deposition. A highly significant positive correlation was found between sputtering time and thickness of the achieved coatings. AFM revealed a reduction in the surface roughness of 316L SS substrates sputtered with all coating materials, significantly seen in V coatings. Conclusions: Sputtering time and coating material play a significant role in terms of microstructure and topography of the achieved coatings being the best in the Ta group; moreover, surface roughness was significantly improved by V coatings. Likewise, it is found to be sputtering time independent for all used coatings.

The value of prognostic and predictive parameters in early-stage lung adenocarcinomas: A comparison between biopsies and resections.

INTRODUCTION: Since lung adenocarcinoma (LUAD) biopsies are usually small, it is questionable if their prognostic and predictive information is comparable to what is offered by large resection specimens. This study compares LUAD biopsies and resection specimens for their ability to provide prognostic and predictive parameters. METHODS: We selected 187 biopsy specimens with stage I and II LUAD. In 123 cases, subsequent resection specimens were also available. All specimens were evaluated for growth pattern, nuclear grade, fibrosis, inflammation, and genomic alterations. Findings were compared using non-parametric testing for categorical variables. Model performance was assessed using the area under the curve for both biopsies and resection specimens, and overall (OS) and disease-free survival (DFS) was calculated. RESULTS: The overall growth pattern concordance between biopsies and resections was 73.9%. The dominant growth pattern correlated with OS and DFS in resected adenocarcinomas and for high-grade growth pattern in biopsies. Multivariate analysis of biopsy specimens revealed that T2-tumors, N1-status, KRAS mutations and a lack of other driver mutations were associated with poorer survival. Model performance using clinical, histological and genetic data from biopsy specimens for predicting OS and DSF demonstrated an AUC of 0.72 and 0.69, respectively. CONCLUSIONS: Our data demonstrated the prognostic relevance of a high-grade growth pattern in biopsy specimens of LUAD. Combining clinical, histological and genetic information in one model demonstrated a suboptimal performance for DFS prediction and good performance for OS prediction. However, for daily practice, more robust (bio)markers are required to predict prognosis and stratify patients for therapy and follow-up.

Accuracy of markerless registration methods of DICOM and STL files used for computerized surgical guides in mandibles with metal restorations: An in vitro study.

STATEMENT OF PROBLEM: Digital imaging and communications in medicine (DICOM) files together with surface scans must be accurately registered in virtual implant planning software programs to match real-life dimensions and ensure correct plan transfer through computer-aided manufactured surgical guides. PURPOSE: The purpose of this in vitro study was to evaluate the accuracy of 3 different registration methods of DICOM data with and without metal restorations and a metal artifact reduction (MAR) tool for surface scans. MATERIAL AND METHODS: Thirteen dentate mandibles were assigned to each group of this study (n=39). Baseplate wax was adapted to the bone surfaces of each mandible, and 5 radiopaque markers were attached. A desktop scanner was used to obtain control scans. The groups of metal-free mandibles (MFM) and mandibles with metal restorations (MRM) were scanned to obtain DICOM data without a MAR tool. Additional DICOM data for the MRM were obtained with the MAR tool (MRM-MAR). Point-based registration (PBR), best-fit registration (BFR), and automatic registration (AR) were used to align standard tessellation language (STL) and DICOM data, and 3 data sets were exported. Radiographic markers on each data set were compared with those on the control scan, and positional deviations were calculated and statistically evaluated with 1-way ANOVA followed by multiple pairwise comparisons, independent samples t test, and 2-way ANOVA (α=.05). RESULTS: Within each group, PBR had the lowest deviation values with statistical significance in the MFM and the MRM-MAR groups (P<.001). AR showed failure in the MRM and the MRM-MAR groups. Statistically significant differences were found on comparing the average deviations among the 3 groups for PBR only (P<.001). No association was found between deviation values and the presence or absence of metal restoration, while a positive association was found with the type of registration method (P<.001). CONCLUSIONS: PBR had the highest accuracy level compared with AR and BFR methods. An increase in the number of calculations resulted in more deviation values. The MAR tool had a positive effect on PBR in mandibles with metal restorations.

Evaluation of retention and wear of a titanium-formed stud overdenture attachment with different interimplant angulations after simulated clinical use: An in vitro study.

STATEMENT OF PROBLEM: How implant alignment impacts stud attachment retention and wear-induced alterations, notably when the attachment exhibits metal-to-metal frictional interlocking, is unclear. PURPOSE: The purpose of this in vitro study was to evaluate the effect of the interimplant angulation on retention forces and wear changes before and after 2 years of simulated clinical use of implant overdentures retained by titanium stud overdenture attachments. MATERIAL AND METHODS: The canine regions of 3 identical edentulous mandibular models were used to receive 2 dental implants analogs with TiTach attachments (Dental Evolutions, Inc) at interimplant angulations of 0, 30, and 60 degrees. Six identical overdentures were constructed over each model (n=6). A universal testing machine was used to determine overdenture retention forces at 0, after 1440, and after 2880 insertion and removal cycles to simulate the average insertion and removal cycles in 12 and 24 months. A stereomicroscope, a laser microscope, and a scanning electron microscope were used to evaluate the wear in the attachments. A linear regression model, ANOVA, and the Kruskal-Wallis tests were used to analyze the data (α=.05). RESULTS: All groups demonstrated reduced retention over the study duration (P<.001). The retention forces of the 0- and 30-degree groups were not significantly different after 2880 insertion and removal cycles, but both were significantly higher than those of the 60-degree group (P=.002). Within each group, the wear pattern of the matrix cap was more noticeable than that of the patrix abutment, with increased wear changes as interimplant angulation increased (P<.001). CONCLUSIONS: TiTach attachments could retain overdentures on parallel and divergent implants with a 30-degree angle of interimplant angulation. However, at a 60-degree angle of interimplant angulation, considerable reduction in retention forces and increased wear changes were observed after 2 years of simulated clinical use.

Protease production and molecular characterization of a protease dipeptidyl-aminopeptidase gene from different strains of Sordaria fimicola.

The current research was designed to reach extracellular protease production potential in different strains of Sordaria fimicola which were previously obtained from Dr. Lamb (Imperial College, London) from North Facing Slope and South Facing Slope of Evolution Canyon. After initial and secondary screening, two hyper-producers strains S2 and N6 were selected for submerged fermentation and cultural conditions including temperature, pH, incubation period, inoculum size, substrate concentration, and different carbon and nitrogen sources were optimized for enzyme production. S2 strain showed maximum protease production of 3.291 U/mL after 14 days of incubation at 30 °C with 7 pH, 1% substrate concentration and 1 mL inoculum, While N6 strain showed maximum protease production of 1.929 U/mL under fermentation optimized conditions. Another aim of the present research was to underpin the biodiversity of genetics and post-translational modifications (PTMs) of protease DPAP (peptidyl-aminopeptidase) in Sordaria fimicola. Five polymorphic sites were observed in amino acid sequence of S. fimicola strains with reference to Neurospora crassa. PTMs prediction from bioinformatics tools predicted 38 phosphorylation sites on serine residues for protease peptidyl-aminopeptidase in S1 strain of S. fimicola while 45 phosphorylation sites on serine in N7 strain and 47 serine phosphorylation modifications were predicted in N. crassa. Current research gave an insight that change in genetic makeup effected PTMs which ultimately affected the production of protease enzyme in different strains of same organism (S. fimicola). The production and molecular data of the research revealed that environmental stress has strong effects on the specific genes through mutations which may cause genetic diversity. S. fimicola is non- pathogenic fungus and has a short life cycle. This fungus can be chosen to produce protease enzyme on a commercial scale.

Comparison of the strain developed around implants with angled abutments with two reinforced polymeric CAD-CAM superstructure materials: An in vitro comparative study.

STATEMENT OF PROBLEM: The strain developed around implants with angled abutments should be considered when selecting a superstructure material. Studies that evaluated the strain developed around implants with angled abutments when using fiber-reinforced polymer as the implant superstructure material are lacking. PURPOSE: The purpose of this in vitro study was to assess the strain developed around implants with angled abutments (15 and 25 degrees) of biocompatible high-performance polymer (BioHPP) and reinforced nanohybrid polymer with a multilayered glass fiber (TRINIA) superstructure under axial and oblique loading. The strain developed around implants was evaluated by using strain gauges. MATERIAL AND METHODS: Thirty-two polyurethane test blocks were divided into 2 main groups (n=16) according to the degrees of buccal tilting of the implant platform (15 and 25 degrees). Each group was divided into 2 subgroups (n=8), and each subgroup received different superstructure materials (BioHPP or TRINIA). Two buccal and palatal strain gauges were installed on their corresponding prepared sites to measure the microstrains in the medium surrounding the implant. A universal testing machine was used to apply the static load from 0 to 100 N in the axial and 45-degree oblique direction, with the loading tip of the device on the loading point at the central fossa of the crown. For each tested implant, loads were applied, microstrains were recorded with the strain gauges, and the strain developed around the implant was statistically evaluated with 1-way ANOVA, followed by multiple pairwise comparisons by using the Bonferroni adjusted significance level (α=.05). RESULTS: For superstructure materials, the microstrain values recorded around implants restored with TRINIA were significantly lower than those restored with BioHPP in all groups (P<.001). The 25-degree implant angulation recorded significantly higher microstrain than 15 degrees buccally and palatally when axial and oblique loads were applied (P<.05). The microstrain was significantly higher in the oblique load than in the axial load in both the BioHPP and TRINIA groups in 15- and 25-degree implant angulations on the buccal and palatal sides (P<.001). CONCLUSIONS: The strain developed around dental implants was significantly affected by the superstructure material. The microstrain was considerably higher when the implant abutment angulation increased. When a 45-degree loading direction was used, this tendency became more pronounced.

Simultaneous renal infarction and splenic infarction as a possible initial manifestation of COVID-19: A case report.

We recommend testing for SARS-CoV-2 in a patient with an unexplained thromboembolic event, even in the absence of fever or respiratory symptoms.

Aortic arch thrombosis complicated by an embolic stroke in a patient with COVID-19: A case report.

INTRODUCTION: Aortic thrombosis is an uncommon condition with serious embolic complications. COVID-19 is currently recognized to be associated with both venous and arterial thrombosis. However, only a limited number of COVID-19 cases associated with aortic thrombosis have been reported in the literature since the beginning of the pandemic. CASE PRESENTATION: A 66-year-old lady was admitted to our hospital with acute ischemic stroke. Floating aortic arch thrombus was detected incidentally on CT imaging. Interestingly, the patient reported a history of fever and cough and was found to have COVID-19 pneumonia based on nasopharyngeal polymerase chain reaction (PCR) and imaging. The patient received three months of anticoagulant therapy, and repeated imaging study did not reveal any aortic thrombus. CLINICAL DISCUSSION: COVID-19 related aortic thrombosis has been reported chiefly in severe cases. The SARS-CoV-2 can directly infect the endothelium of the vessels, which might explain the occurrence of arterial thrombosis in milder COVID-19 cases with the absence of the hyperinflammatory state. The management guideline for aortic thrombosis is scarce and based only on case reports and series. CONCLUSION: Aortic thrombosis is a devastating condition that can be easily missed without clinical suspicion. Our patient developed acute ischemic stroke, most likely embolic originating from the aortic thrombus. The clinician should consider this condition in any COVID-19 patient presenting with thromboembolic events, such as stroke or acute limb ischemia. Further study is required to explain the pathophysiology of arterial/venous thrombosis in mild-moderate COVID-19 cases.

Do orthodontists aim to decrease the duration of fixed appliance treatment?

OBJECTIVES: The aim of the present study was to investigate the trends in the use of fixed appliance and accelerated orthodontics to decrease the treatment duration. Further, this study aimed to assess the effect of demographic factors on the participant's choice of treatment modality. METHODS: This was a cross-sectional study in the form of questionnaire-based online survey especially designed and distributed to 265 orthodontists via email. The questions aimed to collect basic information about the participants and respondents' choices for decreasing the treatment duration. The data were analyzed according to gender, level of academic education and years of clinical experience using Chi-square test. RESULTS: A response rate of 85.2% was reported. Most of the orthodontists aimed to reduce the treatment duration by the biomechanical (66.8%) and surgical approaches (27.4%). The use of sliding mechanics (69.4%) and one-step retraction was more common (66.3%). MBT bracket prescription was more prevalent (51.7%), followed by Roth (41.1%). Conventional brackets were used more than self-ligating brackets, and aesthetic brackets were avoided by one third of the respondents. NiTi wires were the most commonly used wires during the alignment stage (44.2%). However, the effect of gender, years of clinical experience and specialty level of education showed some effects on the use of certain techniques and clinical practice of the respondents. CONCLUSIONS: Most of the orthodontists aimed to decrease orthodontic treatment duration by using biomechanical and surgical approaches. Gender and clinical experience to a certain extent affected the participants' choice during orthodontic treatment.

An Incidental Finding of Scalp Angiosarcoma: A Case Report.

Scalp angiosarcoma is a malignant tumor of the vascular endothelial cells. We present the case of an elderly male patient with a history of urinary bladder transitional cell cancer and trauma (falling on his head) who came to the emergency department with scalp swelling, which was found on brain imaging to infiltrate into the skull, reaching the dural matter. A biopsy was done, which showed angiosarcoma, which is rare for that area. Further studies are recommended to establish if there is a possible genetic association between both cancers (urinary bladder transitional cell cancer and scalp angiosarcoma) as both arise from endothelial cells.

Moral injury and the COVID-19 pandemic: A philosophical viewpoint.

INTRODUCTION: Much has changed in healthcare during the coronavirus disease (COVID)-19 pandemic. Medicine, a profession of traditional principles and virtues, has faced unprecedented challenges in the light of scarce and unequal distribution of ventilators, testing, and personal protective equipment. Healthcare workers have been- and are increasingly likely to be- forced into situations that require difficult decision making under life-and-death conditions. Concepts of "medical necessity" and "maximum benefit" challenge healthcare systems that already struggle to manage unequal treatment and access to services, giving rise to moral distress and moral injury on the front lines. METHODS: This article focuses on moral injury in the context of coronavirus disease (COVID)-19 pandemic. I review recent literature to highlight the psychological impact of many morally-injurious events that have been reported during the COVID-19 pandemic. With the help of a clinical vignette, I point out how healthcare systems adopt many utilitarian policies in times of excessive healthcare burden. A viewpoint is offered that many morally injurious events happen when healthcare workers, traditionally practicing Kantian and virtue ethics, are forced to follow utilitarian policies of healthcare system. CONCLUSION: One form of moral injury may arise from inherent conflicts between individual deontological moral judgments and organizational utilitarian moral judgments. More research is needed to validate the philosophical viewpoint as well as to explore whether increased awareness and education of key principles within moral philosophy can better equip healthcare workers in situations when public health takes precedence over individual health.

Retention Protocols and Factors Affecting Retainer Choice among Iraqi Orthodontists.

BACKGROUND: To identify the most common retention protocols practiced by Iraqi orthodontists using a specially designed e-survey. Furthermore, this study aimed to assess the effect of sociodemographic factors on the participant's choice. METHODS: Two hundred and twenty-five questionnaires with 23 multiple choice questions were sent to members of the Iraqi Orthodontic Society. The questionnaire was organized into four sections representing information about sociodemographic status of the orthodontists, factors affecting the selection of the retention system, commonly used retainers in the upper arch and lower arch, and duration of the retention system. The chi-square test was used to test the significant association between different variable and sociodemographic factors. RESULTS: The response rate was 87.5%. The majority of the respondents considered the original malocclusion (80.2%) and clinical experience (49.7%) as the main factors for choosing the retention protocol. In the maxillary arch, a combination of vacuum-formed retainer and fixed retainer (35%) was mostly applied; in the mandibular arch, a fixed retainer was mainly used (46.7%). Most of the respondents recommended initial full-time wearing of a removable appliance (78.2%), especially in the first 3-6 months (47.2%). According to the respondents, bonding a fixed retainer to all anterior teeth was most common (79.7%), fabricated, and adapted directly inside the patient's mouth (75.1%). More than half used flowable composite (54.8%) and recommend leaving the retainer forever (53.8%). Most of the variables showed a statistically significant association between the sociodemographic factors and type, duration, and fabrication of the retainer used. CONCLUSIONS: A combination of removable and fixed retainers was commonly used in orthodontics retention, and sociodemographic factors significantly affected retainer choice.

Predictive and prognostic value of 256-slice computed tomography angiography in patients with suspected coronary artery diseases.

BACKGROUND: Coronary computed tomography angiography (CCTA) is commonly used to diagnose coronary artery diseases (CADs). We aimed to determine the utility of CCTA among patients suspected with CAD at the Prince Sultan Cardiac Center Qassim. MATERIALS AND METHODS: CCTA results of 425 cardiac patients, complaining of chest pain with suspected CAD, were used to classify coronary artery stenosis into two types: obstructive if the luminal stenosis was ≥50% or nonobstructive if it was <50%. Follow-ups were conducted through clinic or phone-based interviews to document any of the following endpoints: nonfatal myocardial infarctions (MIs) or cardiac deaths (CDs), representing the major cardiac events. All other cardiac cases, including hospitalization with unstable angina, and/or late coronary revascularization, were documented. RESULTS: Patients with a normal coronary artery were 278 (65.5%). The number of patients with nonobstructive and obstructive diseases was 85 (20%) and 62 (14.5%), respectively. After 19.6 ± 7 months of follow-up, 21 cardiac events occurred in twenty patients: five major adverse events (two CDs and three nonfatal MIs), ten hospitalizations due to unstable angina, and six late coronary revascularizations. Furthermore, the cumulative all-cardiac-event rates in patients with normal coronary arteries, nonobstructive CAD, and obstructive CAD were 3 (1%), 7 (8.2%), and 11 (17.7%), respectively. However, patients with normal CCTA had no major cardiac events during the follow-up. CONCLUSION: CCTA can provide valuable prognostic information on patients with suspected CAD. Patients are likely to have excellent intermediate outcomes if the coronary arteries are confirmed to be normal by CCTA.