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A hybrid finite element/volume model that captures the flow and pressure drop characteristics in highly porous woven matrix media is developed. It is demonstrated that the characteristics of flow through a woven matrix composed of fibers with circular cross-section can be modeled using the finite element method with an equivalent woven matrix system composed of fibers with square cross-section. From simulations of fluid flow in a range of models with varying sizes, it is demonstrated that changes in the thickness of the finite element model in the fluid flow direction and defects in the lay-up of the woven matrix layers have significant effects on the pressure drops. Higher defect densities result in greater pressure drops as they disrupt the steady flow of fluid in the through-thickness direction. The pressure drops obtained in the finite element model simulations of thick models that contained some defective layers match well with experimental observations. [ABSTRACT FROM AUTHOR]

This study aims to investigate the effect of using an artificial intelligence (AI) system (Diagnocat, Inc., San Francisco, CA, USA) for caries detection by comparing cone-beam computed tomography (CBCT) evaluation results with and without the software. 500 CBCT volumes are scored by three dentomaxillofacial radiologists for the presence of caries separately on a five-point confidence scale without and with the aid of the AI system. After visual evaluation, the deep convolutional neural network (CNN) model generated a radiological report and observers scored again using AI interface. The ground truth was determined by a hybrid approach. Intra- and inter-observer agreements are evaluated with sensitivity, specificity, accuracy, and kappa statistics. A total of 6008 surfaces are determined as 'presence of caries' and 13,928 surfaces are determined as 'absence of caries' for ground truth. The area under the ROC curve of observer 1, 2, and 3 are found to be 0.855/0.920, 0.863/0.917, and 0.747/0.903, respectively (unaided/aided). Fleiss Kappa coefficients are changed from 0.325 to 0.468, and the best accuracy (0.939) is achieved with the aided results. The radiographic evaluations performed with aid of the AI system are found to be more compatible and accurate than unaided evaluations in the detection of dental caries with CBCT images.

Objectives: The aim of this cross-sectional study was to assess the proximity of maxillary second molar (MSM) and maxillary tuberosity (MT) to mandibular foramen (MF) to perform successful Vazirani-Akinosi nerve block (VANB) technique., Methods: Cone beam computed tomography (CBCT) images of 2613 sides of the jaw were selected for the study. The vertical distance from MSM to the MF and the vertical distance from MT to the MF and from MT to the posterior border of the ramus (PR) were measured and compared between males and females using independent samples t test., Results: The mean values of all vertical measurements were higher in males than in females, and the difference was statistically significant in case of the vertical distance from MSM to the MF and the vertical distance from MT to the PR (P < .05)., Conclusion: This study showed the gender differences in MSM and MT measurements used to locate MF in VANB technique. This fundamental knowledge should be considered in performing VANB technique., (© 2022. The Author(s) under exclusive licence to Japanese Society for Oral and Maxillofacial Radiology.)

Low-cost desktop-sized fused deposition modeling (FDM) printers have been widely embraced by small to large-scale institutions and individuals. To further enhance their utility and increase the range of materials that they can process, this work proposes a low-cost solution that adapts to low-cost desktop-sized extruders and enables them to fabricate filaments comprising a wide range of nonorganic reinforcing particles. This solution will fill a gap in the field, as low-cost fabrication techniques for reinforced filaments have been lacking. In the proposed solution, particles are heated and deposited on thermoplastic pellets to form a coating. Coated pellets are subsequently extruded using a low-cost desktop single-screw extruder. The effectiveness of the process is demonstrated by fabricating polylactic acid (PLA) filaments reinforced with two types of reinforcements, namely, dune sand and silicon carbide. Filaments' stiffness and strength were measured, and their microstructure along their lateral and longitudinal directions were investigated. Improvements in tensile strength (up to 8%) and stiffness (up to 4.5%) were observed, but at low reinforcement levels (less than 2 wt%). Results showed that the proposed process could be used to fabricate filaments with multiple types of particles. The produced filaments were successfully used to fabricate 3D parts using a commercial desktop FDM printer.

The prevalence and anatomical features of C-Shaped Mandibular Second Molars (MSMs) are rarely studied in Jordanian sub-population. This study then took a part to evaluate the prevalence of C-shaped in MSMs using cone-beam computed tomography (CBCT) in the Jordanian sub-population. It used a cross-sectional design and three thousand scans collected over eight years between 2011 and 2019. The data were then reviewed for whether they were fully formed of MSMs. A total of 2037 cases that had 2845 MSMs were evaluated to identify C-shaped canals at coronal, middle, and apical sites. An oblique slicing module perpendicular to the long axis of MSMs was used to evaluate the teeth. The type and frequency of C-shaped canals, as well as the correlations between sex and side (right/left) and between sex and groove direction (buccal/lingual) were measured using the chi-square test on SPSS software at the significance level of 95%. A total of 342 teeth of 243 patients were C-shaped molars, which comprised 12% of the patient's teeth and 99 of them as a bilateral C-shaped canal with mean age of 40 years and sex ratio of 2:1 between female and male. With the limitations of this study, the lingual groove and type 3 were the most common properties of MSM. Besides, the Jordanian population mostly had C-shaped canals., (© 2022. The Author(s).)

Abstract: Calvarial critical-size defect has been used to assess techniques and materials in the bone regeneration field. Previous studies utilized young adult rats with 3 months of age, which might not reflect the geriatric conditions. This study aimed to assess the dimensions of the calvarial critical-size defect in aged rats.Seventy-two rats in a randomized block design were allocated into a control young adult (11-12 weeks), and a test old group (22-24 months). Both groups were divided according to bone defect's size: 3 mm, 5 mm, and 7 mm defects, which were surgically created and followed for 4 and 8 weeks. Radiographic and histologic analyses were performed. Based on the results, additional groups with 4 mm defect size were added following the same protocols. Young groups yielded higher bone volumes, defect closure percentages, and density of newly formed bone. Closure of cranial defects was only observed in 3 mm defects in both age groups after 8 weeks; however, the 4 mm defect group demonstrated bony bridging after 8 weeks in young but not old rats. Results confirmed that 5-mm defect is considered a critical size for calvarial bone defects in young adult rats; however, 4 mm defect might be considered critical size for the aged rats after 8 weeks., Competing Interests: The authors report no conflicts of interest., (Copyright © 2021 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of Mutaz B. Habal, MD.)

(1) Background: When dental implants are placed at the esthetic zone, facial bone fenestration might be expected. This study aimed to evaluate the biomechanical effect of bone augmentation around implants with facial bone fenestration defects using the finite element method. (2) Methods: An anterior maxillary region model with facial concavity was constructed with a threaded implant inserted following the root direction, resulting in apical threads exposure to represent the fenestration model. Several bone coverage levels were simulated by gradually shifting the deepest concavity point buccally, mimicking bone augmentation surgeries with different bone fill results. Oblique forces were applied, and analysis was performed. (3) Results: Peak compressive stress magnitude and distribution varied according to the level of exposure and facial concavity depth. The fenestration model demonstrated a slightly lower peak peri-implant bone stress, smaller implant displacement, and smaller bone volume with strain levels above 200 µ strain. A gradual increase in compressive stress, implant displacement, and bone volume exhibited strain level above 200 µ strain was observed with the increased bone fill level of the facial bone fenestration. (4) Conclusions: Exposure of implants apical threads at the maxillary anterior region does not significantly affect the peri-implant stress and strain results. However, increasing the buccolingual width and eliminating the buccal concavity might increase the peri-implant bone volume exhibited favorable loading levels.

Objectives:  The diagnosis and treatment of patients with sleep disorders are the most challenging issues in dentistry. The aim of this study was to assess the knowledge among dental interns in Northern Jordan about sleep medicine and sleep disorders., Materials and Methods:  This cross-sectional study was performed using the Assessment of Sleep Knowledge in Medical Education (ASKME) questionnaire. The questionnaire was given to 88 dental interns (52 females and 36 males) in Northern Jordan. Chi-squared test was utilized for data analysis., Results:  The mean score of the ASKME questionnaire was 12 out of 30 (40%). The majority of dental interns (88.6%) correctly answered ≤ 50% of the questions. No association was found between gender and score results., Conclusions:  Dental interns in Northern Jordan have a low level of knowledge about sleep medicine and sleep disorders. Dental faculties should provide courses related to sleep medicine throughout undergraduate education., Competing Interests: None declared., (European Journal of Dentistry. This is an open access article published by Thieme under the terms of the Creative Commons Attribution-NonDerivative-NonCommercial-License, permitting copying and reproduction so long as the original work is given appropriate credit. Contents may not be used for commercial purposes, or adapted, remixed, transformed or built upon. (https://creativecommons.org/licenses/by-nc-nd/4.0/).)

Objectives: The aim of this study was to assess the visibility of mandibular canal (MC) on cone beam CT (CBCT) images using a medical review monitor under two different calibration modes. The effect of age, gender, and location of the dental implant site was also assessed., Materials and Methods: CBCT images of 428 dental implant sites were selected for the study. Images were displayed twice on a medical review monitor using two different calibration modes: standard and DICOM, and two observers evaluated the visibility of the MC using four-point scoring scale (1-4, poor to excellent). Cohen Kappa was used to assess intra and inter-rater reliability. Chi-square test was used to compare proportions of MC visibility by gender and location and one-way ANOVA was used to compare mean age and MC visibility., Results: Each observer classified the visibility of MC with a total agreement of 100% between DICOM mode and standard mode (Kappa = 1, P < 0.001 for each observer). In each mode, a strong agreement (inter-rater reliability) was detected between the observers (Cohen's kappa = 0.88 for both modes, P < 0.001) with a percent agreement of 95.3% for each mode. Gender and location were not statistically associated with MC visibility (P > 0.05). Age, however, was a significant predictor of MC visibility (P < 0.05)., Conclusions: DICOM calibration had no added value over standard calibration for assessing the visibility of MC at dental implant sites on a medical review monitor. Only the age had significant effect on the visibility., Competing Interests: None

Background: Differences between dental students in terms of social, economic and cultural backgrounds are likely to impact their professional career plans. The aim of this study was to explore the professional career plans among final year dental students from different backgrounds at a single Middle Eastern institution (Jordan university of Science and Technology-JUST)., Methods: Fifth year dental students at JUST were invited to fill out a paper based self-administered questionnaire. Data was collected on students` demographics, their future career plans and the impact of social and economic changes on such plans, their interest in postgraduate studies and the specialty of choice in addition to the influence of a group of factors on that choice. Data was also collected on the value of non-academic workshops, guidance regarding career plans, participants` preferred pattern of work (full-time versus part-time) and retirement plans. Students were categorized according to their nationalities. Pearson's chi squared test, one way ANOVA and post hoc tests were used to measure statistical significance between measured variables and backgrounds of participants. The level of significance was set at P ≤ 0.05., Results: A total of 227 students completed the survey (response rate = 84%). 47% of the participants were Jordanians, 27% were Malaysians, 11% were from Gulf States (Saudi Arabia, Bahrain, Kuwait and Qatar), 10% were from conflict zones in the Middle East (Syria, Iraq, Palestine and Yemen) and 5% comprised students from other nationalities. Significant differences were found between students from different backgrounds in their funding sources (Chi square = 132, P < 0.01), practice plans (Chi square = 43, P < 0.01), the impact of social and economic changes on their career choices (Chi square = 34, P < 0.01), planned work pattern within the first 10 years post-graduation (chi square = 18, P < 0.05) and 10-20 years after graduation (69%, Chi square = 22, P < 0.01) and retirement plans (Chi square = 25, P < 0.05). Students from different nationalities agreed on most factors affecting their choice of a specialty, except for the reputation of the specialty (P < 0.05)., Conclusion: Several differences in career plans were found between dental students from variable backgrounds studying a single institution. Many of these disparities could reflect variations in socioeconomic backgrounds.

Objective: Using cone-beam computed tomography (CBCT) images, the aim of the study was to evaluate the usefulness of measuring radiographic density of the axis vertebra (RDAV) in patients at risk of osteoporosis., Materials and Methods: Two hundred and forty-seven old patients (109 males and 138 females) aged between 50 and 80 years (mean age: 59.68 ± 7.27) were examined by CBCT. Using InVivoDental, v. 5.0 (Anatomage Inc., San Jose, CA), RDAV and mental index (MI) were measured twice and correlated using Pearson's correlation coefficients. Patients were divided into two categories: high risk and low risk of osteoporosis using 3.1 mm of MI as a cutoff value, and the mean value of RDAV was compared and correlated using independent samples' t -test and regression analysis. Receiver-operating characteristic (ROC) curve analysis was also used to examine the predictive power of RDAV., Results: The mean value of RDAV was moderately correlated with MI ( r = 0.32), and in patients at low risk of osteoporosis, the mean value of RDAV was significantly higher than in patients at high risk of osteoporosis. In multivariate binary logistic regression, the odds of being at risk of osteoporosis decreased by 1% with one unit increase in RDAV (odds ratio = 0.988, 95% confidence interval: 0.983-0.993; P < 0.005). ROC analysis showed that the mean value of RDAV had a high predictive power for predicting patients at risk of osteoporosis (area under the curve = 0.761 for females and 0.649 for males)., Conclusions: Measuring RDAV is considered useful in predicting patients at risk of osteoporosis., Competing Interests: There are no conflicts of interest.

Objective: Using cone beam computed tomography (CBCT) images, the aim of the study was to evaluate the usefulness of measuring bone density of mandibular condyle (BDMC) in patients at risk of osteoporosis., Materials and Methods: Two hundred and four mandibular condyles (46 condyles from males and 158 condyles from females) were examined by CBCT. Using inVivo software (Anatomage, San Jose, Calif), BDMC and mental index (MI) were measured by two observers and correlated using Pearson's correlation coefficients. Patients were divided into high risk and low risk of osteoporosis using 3.1 mm of MI as a cutoff value, and the mean value of BDMC was compared and correlated using independent samples t -test and regression analysis. Receiver-operating characteristic (ROC) curve analyses were also used to examine the predictive power of BDMC., Results: The mean value of BDMC was moderately correlated with MI ( r = 0.38), and in female patients at low risk of osteoporosis, the mean value of BDMC was significantly higher than in patients at high risk of osteoporosis. In multivariate linear regression analysis, being at risk of osteoporosis is significantly affected by BDMC, age, and gender. ROC analysis showed that the mean value of BDMC had a moderate predictive power for predicting patients at risk of osteoporosis (area under the curve = 0.621 for females and 0.649 for males)., Conclusions: Measuring BDMC is considered useful in predicting patients at risk of osteoporosis., Competing Interests: There are no conflicts of interest.

The psychological aspects of chronic pain conditions represent a key component of the pain experience, and orofacial pain conditions are not an exception. In this review, we highlight how psychological factors affect some common oral mucosal and orofacial pain conditions (namely, oral lichen planus, recurrent aphthous stomatitis, burning mouth syndrome, and temporomandibular disorders) with emphasis on the significance of supplementing classical biomedical treatment modalities with appropriate psychological counseling to improve treatment outcomes in targeted patients. A literature search restricted to reports with highest relevance to the selected mucosal and orofacial pain conditions was carried out to retrieve data., Competing Interests: There are no conflicts of interest.

Objective: The aim of this study was to investigate the predictability of bone density at posterior mandibular implant sites using cone-beam computed tomography (CBCT) intensity values., Materials and Methods: CBCT cross-sectional images for 436 posterior mandibular implant sites were selected for the study. Using Invivo software (Anatomage, San Jose, California, USA), two observers classified the bone density into three categories: low, intermediate, and high, and CBCT intensity values were generated., Results: Based on the consensus of the two observers, 15.6% of sites were of low bone density, 47.9% were of intermediate density, and 36.5% were of high density. Receiver-operating characteristic analysis showed that CBCT intensity values had a high predictive power for predicting high density sites (area under the curve [AUC] =0.94, P < 0.005) and intermediate density sites (AUC = 0.81, P < 0.005). The best cut-off value for intensity to predict intermediate density sites was 218 (sensitivity = 0.77 and specificity = 0.76) and the best cut-off value for intensity to predict high density sites was 403 (sensitivity = 0.93 and specificity = 0.77)., Conclusions: CBCT intensity values are considered useful for predicting bone density at posterior mandibular implant sites., Competing Interests: There are no conflicts of interest.

Purpose: To compare the mesiodistal space measurements of single-implant sites on panoramic and oblique images generated by cone-beam CT (CBCT)., Methods: CBCT images for 101 single-implant sites of 66 patients referred for pre-surgical radiographic implant planning were selected for the study; 15-mm-thickness panoramic images were reformatted and used for measuring mesiodistal space dimensions. The measurements were repeated and compared with those of thin oblique images (200-300 μ) using Wilcoxon signed rank test. The correlation between measurements in addition to intra-observer agreement was evaluated by Pearson's correlation coefficients., Results: All mesiodistal space measurements on panoramic and oblique images generated by CBCT were strongly correlated and there were no statistically significant differences between them (P < 0.05)., Conclusions: Both panoramic and oblique images generated by CBCT can be used for measuring mesiodistal space dimensions of single-implant sites.

Engineering research may provide tools to the individual as well as to the public in general, to effectively monitor wellness and health patterns, such as metabolic rate and weight control. Ketone bodies and acetone gas emissions in exhaled breath and skin, in particular, may be used as biomarkers of fatty acid metabolism and may be used in diet control. Two types of technologies, resistive chemosensors and chemomechanical actuators are outlined here as examples of such tools currently under development and of great promise.

Objective: To determine if the differing contrast resolution of various LCD monitors affects the reliability or accuracy of measurements of proposed implant sites., Materials and Methods: Edentulous areas of human dry skulls were marked with radiopaque markers in order to standardize the plane of the transverse cross-sections of the ridges and path of measurements. The skulls were imaged by a CBCT device and the images stored in proprietary format on the workstation. The data sets were then transferred, with the proprietary reformatting software, to two different laptops using CDs. Transverse cross-sectional images of the ridges were reformatted on all three computers and ridge dimensions were recorded using the linear measurement tool of the proprietary software. Ridge dimensions were recorded directly from the three different monitors by two observers and compared to measurements recorded directly from the bone. The measurement errors and intra- and inter-examiner reliability were calculated for each monitor and compared with each other., Results: Intra- and inter-examiner reliability scores for the measurements recorded from all three devices were very high and ranged between 0.993-0.999. The mean of the absolute errors was 0.55 mm for the workstation, 0.61 mm for laptop 1 and 0.68 mm for laptop 2. The absolute errors were statistically significant for all three monitors (p-value < 0.001), but there was no statistically significant difference between the absolute errors obtained from the three monitors., Conclusions: No differences in the reliability or accuracy of measurements of implant site dimensions were obtained using color LCD monitors with different contrast resolution capabilities.

Objective: the aim of the study was to evaluate the usefulness of cone beam CT (CBCT) in temporomandibular joints (TMJs) with soft tissue pathology., Methods: 106 TMJs of 55 patients with temporomandibular disorder (TMD) were examined by MRI and CBCT. MR images were used for the evaluation of disc displacement, disc deformity, joint effusion and obscurity of temporal posterior attachment (TPA). CBCT images were evaluated for the presence or absence of osseous abnormalities. The chi(2) test was used to analyse the association between MRI and CBCT findings., Results: MRI of 106 TMJs revealed disc displacement, disc deformity, joint effusion and obscurity of the TPA in 68, 73, 28 and 27 joints, respectively. Of the 68 TMJs with disc displacement, anterior disc displacement without reduction (ADDWR) was seen most frequently (47/68). CBCT imaging found 65 TMJs were characterized by the presence of osseous abnormalities and were significantly associated with disc deformity and ADDWR (P < 0.05). There was no statistically significant association between the presence of joint effusion and obscurity of TPA and TMJ osseous abnormalities., Conclusions: TMD patients with confirmed ADDWR or disc deformity on MRI are at risk of having osseous abnormalities in the TMJ and further examination with CBCT is recommended.

Objective: With cone beam CT (CBCT) as the reference standard, the objective of this study was to determine the diagnostic accuracy of MRI for assessing osseous abnormalities of the temporomandibular joint (TMJ)., Methods: 106 TMJs from 55 patients with temporomandibular disorder were examined by CBCT and MRI. CBCT images were evaluated by two experienced oral radiologists with regard to the presence or absence of each of the following eight types of osseous abnormalities: Type 1, destructive and erosive osseous changes of the condyle; Type 2, flattening of the articular surface of the condyle; Type 3, deformity of the condyle; Type 4, sclerosis of the condyle; Type 5, osteophyte formation; Type 6, ankylosis; Type 7, erosion of the articular fossa and/or eminence; and Type 8, sclerosis of the articular fossa and/or eminence. For detection of these osseous abnormalities by MRI, proton density-weighted images and T(2) weighted images were evaluated independently by three observers. Using CBCT findings as the reference standard, the diagnostic performance of MRI for detecting various types of osseous abnormalities was evaluated by calculating its sensitivity and specificity., Results: Out of 106 joints, CBCT revealed Types 1, 2, 3, 4, 5, 6, 7 and 8 abnormalities in 25, 19, 26, 20, 14, 5, 19 and 22 joints, respectively. The mean sensitivities of MRI among the three observers for detecting Types 1, 2, 3, 4, 5, 6, 7 and 8 abnormalities were 61%, 30%, 82%, 40%, 48%, 34%, 61% and 41%, respectively, whereas the mean specificities were 86%, 92%, 91%, 95%, 84%, 98%, 89% and 91%, respectively., Conclusions: Although high specificity (84-98%) was obtained with MRI, this modality showed relatively low sensitivity (30-82%) for detecting osseous abnormalities of the TMJ. The value of MRI for the detection of TMJ osseous abnormalities is considered to be limited.