Search Results (244)

Objectives: Facial soft tissue imaging is crucial in orthodontic treatment planning, and the structured light scanning technology found in the latest iPhone models constitutes a promising method. Currently, studies which evaluate the accuracy of smartphone-based three-dimensional (3D) facial scanners are scarce. This study compares smartphone scans with cone-beam computed tomography (CBCT) images. Materials and Methods: Three-dimensional images of 23 screened patients were captured with the camera of an iPhone 13 Pro Max and processed with the Scandy Pro application; CBCT scans were also taken as a standard of care. After establishing unique image pairs of the same patient, linear and angular measurements were compared between the images to assess the scanner’s two-dimensional trueness. Following the co-registration of the virtual models, a heat map was generated, and root mean square (RMS) deviations were calculated for quantitative assessment of 3D trueness. Precision was determined by comparing consecutive 3D facial scans of five participants, while intraobserver reliability was assessed by repeating measurements on five subjects after a two-week interval. Results: This study found no significant difference in soft tissue measurements between smartphone and CBCT images (p > 0.05). The mean absolute difference was 1.43 mm for the linear and 3.16° for the angular measurements. The mean RMS value was 1.47 mm. Intraobserver reliability and scanner precision were assessed, and the Intraclass Correlation Coefficients were found to be excellent. Conclusions: Smartphone facial scanners offer an accurate and reliable alternative to stereophotogrammetry systems, though clinicians should exercise caution when examining the lateral sections of those images due to inherent inaccuracies. Full article

(1) Background: This study aimed to evaluate the marginal and internal fit of ceramic crowns produced by various digital methods using microcomputed tomography (MCT) imaging. (2) Methods: The ceramic crown preparation was performed on typodont maxillary first premolar. The crown preparation was scanned with an intraoral scanner and a model scanner, and cone-beam computed tomography (CBCT) scans were performed with three different voxel sizes (0.075 mm, 0.1 mm, and 0.15 mm). The space between the crown and prepared teeth was measured at nine different points in both coronal and sagittal sections. Three different digital model acquisition techniques, namely, intraoral scanning, model scanning, and CBCT-based standard tessellation language (STL) reconstruction, were compared in terms of marginal and internal fit. (3) Results: Quantitative analyses revealed that model scanners exhibited the lowest marginal and internal gap values, indicating superior fit compared to intraoral scanners and CBCT-based models. The highest gap values were observed in the CBCT group with a voxel size of 0.15 mm. Overall, crowns obtained from model scanners demonstrated the highest success rates in both marginal and internal fit. (4) Conclusions: In conclusion, this study highlights the critical role of digital scanning accuracy in achieving clinically acceptable prosthetic fits and emphasizes the need for continued technological advancement. Full article

Cone-beam computed tomography (CBCT) offers low radiation, cross-sectional imaging that is a suitable alternative to conventional fan-beam computed tomography (FBCT). The initial experience using in-clinic CBCT in the Rhinology outpatient clinic at Waikato Hospital, New Zealand, is described. The first 5 months of CBCT use for Rhinologic imaging was compared to FBCT use in the equivalent 5-month period one year prior. Data relating to 61 CBCTs and 115 FBCTs was analysed. We compared the time and number of hospital visits required for a confirmed treatment decision (CTD) to be made and the duration of the clinic appointment at which the scan was requested between the two groups. The CBCT group required significantly less time (171 vs. 316 days, p < 0.001) and fewer hospital visits (1.5 vs. 3.2 visits, p < 0.001) before a CTD was made, but a longer appointment duration (86 vs. 53 min, p < 0.001). The use of in-clinic CBCT in Rhinology was therefore associated with reduced time and fewer hospital visits before definitive management was decided, but longer clinic appointments were observed. Increased access to CT imaging may result in increased demand. Expertise is required to optimise the quality of imaging, and we recommend that a dedicated Radiographer be allocated. Full article

Traditional color vision tests lack the sensitivity to detect subtle differences in individuals with normal color vision. The Konan ColorDx Cone Contrast Threshold (CCT) HD test allows the quantitative measurement of color discrimination thresholds for each cone type. This cross-sectional study established normative values for L-, M-, and S-cone contrast sensitivities and evaluated the effects of age and sex on color discrimination thresholds. Participants aged 15–79 years with normal color vision were included (n = 216; 55% female). CCTs were measured monocularly using the Konan ColorDx CCT HD test under standardized conditions, and the influences of age and sex on L-, M-, and S-cone sensitivities were evaluated. In all groups, L-cone sensitivity was the highest, followed by the M- and S-cone sensitivities. Overall contrast sensitivity was significantly higher in females than in males (mean difference = −0.041), especially for adolescents and young adults (20–24 years). Young adults outperformed middle-aged and older adults, with age-related decline most pronounced for S-cone sensitivity in those over 60. The right and left eye sensitivities did not differ. This study provides age- and sex-stratified normative data for the Konan Color Dx CCT HD test, supporting its use for clinical and occupational assessments. Full article

In the field of agriculture, various types of pesticides are used to control crop pests. These chemical agents are applied using nozzles with different geometries. Regardless of their configuration and operational liquid parameters, the applied liquid jet encounters issues with wind drift and penetration efficiency. Therefore, it is necessary to optimize the spraying process. In this study, 3D numerical calculations were performed using computational fluid dynamics (CFD). A two-phase flow model based on the volume of fluid (VOF) method was used to simulate the mixing of water and air. The k-ω SST turbulence model was adopted to capture vortex phenomena. A hollow cone nozzle geometry, commonly used in orchards, was selected. Simulations allowed the analysis of pressure, velocity, and turbulence kinetic energy (TKE) in selected cross-sections. Results show that the maximum velocity of the liquid jet at the nozzle outlet exceeded 23 m/s, with the highest TKE reaching 35 m²/s² in the vortex chamber. The computed spray cone angle was approximately 88°, while the experimental value was 80°, and the simulated mass flow rate differed by 16.7% from the measured reference. The critical flow region was identified between the vortex insert and the ceramic stem, where the highest gradients of pressure and velocity were observed. Full article

Objective: This ex vivo study aimed to evaluate the influence of different acquisition protocols, combining voxel size and field of view (FOV), across four cone-beam computed tomography (CBCT) systems, on the accuracy of alveolar bone level measurements for periodontal assessment. Materials and Methods: A dry human mandible was used, with standardized radiopaque markers placed on the cementoenamel junction (CEJ) of the buccal–mesial and buccal–distal aspects of teeth 34 and 43. CBCT scans were performed using four systems—Veraview^® X800, OP300 Pro^®, I-CAT Next Generation^®, and Orthophos XG^®—applying various combinations of field of view (FOV) and voxel resolution available in each device. Reference measurements were obtained in situ using a digital caliper. CBCT images were exported in DICOM format and analyzed with OnDemand3D software (version 4.6) to obtain paracoronal sections. Linear measurements from the CEJ to the alveolar crest were recorded in triplicate and compared to the gold standard using ANOVA and the Dunnett test (α = 0.05). Results: Protocols with smaller voxel sizes and limited FOVs generally yielded measurements closer to the gold standard. However, some larger-FOV protocols with intermediate voxel sizes also achieved comparable accuracy. Among the systems, the I-CAT showed lower agreement within in situ measurements, while others demonstrated reliable performance depending on the acquisition parameters. Conclusions: The findings suggest that CBCT protocols with smaller voxel sizes and reduced FOVs can enhance measurement accuracy in periodontal bone assessments. Nevertheless, intermediate protocols may offer a balance between diagnostic quality and radiation exposure, aligning with the ALADA principle. This study reinforces the need for standardized acquisition parameters tailored to periodontal imaging. Full article

Background/Objectives: Periodontal and implant therapies frequently require soft tissue augmentation for optimal outcomes. As the hard palate serves as the primary donor site, this study evaluated palatal masticatory mucosa thickness variations in a Saudi population of the Eastern Province using cone-beam computed tomography (CBCT) at a teaching dental hospital, providing site-specific data for clinical applications. Methods: A retrospective cross-sectional analysis of 215 CBCT scans from systemically healthy, non-smoking adults (>18 years) was conducted at the University Dental Hospital. Measurements were taken at 12 standardized sites (3 mm, 6 mm, and 9 mm from the cementoenamel junction) across maxillary canines, premolars, and first molars. Statistical analysis included Friedman’s test and t-tests. Results: Significant site variations were observed, with the second premolar region showing greatest thickness (3.48 ± 0.80 mm at 9 mm) and the first molar region the lowest (1.88 ± 0.63 mm at 3 mm) (p < 0.001). Mucosal thickness generally increased coronally to apically (p < 0.001). Age >35 years correlated with significantly thicker mucosa (p < 0.05), while no statistically significant gender-based differences were observed for all sites (p > 0.05). Conclusions: CBCT provides reliable, non-invasive assessment of palatal mucosa thickness. These findings offer region-specific data for consideration in periodontal and implant procedures involving soft tissue grafting. Full article

For crop protection, electrostatic spraying technology significantly improves deposition uniformity and pesticide utilization through the “wraparound-adsorption” effect of charged droplets. However, existing electrostatic nozzles using hydraulic atomization suffer from low charge-to-mass ratios due to unclear principles for optimizing electrode parameters. To this end, this study designs and evaluates a novel air-assisted hydraulic-atomization hollow-cone electrostatic nozzle. First, the air-assisted hollow-cone nozzle was designed. High-speed imaging was then employed to obtain morphological parameters of the liquid film (length: 2.14 mm; width: 1.96 mm; and spray angle: 49.25°). Based on these parameters, an electric field simulation model of the electrostatic nozzle was established to analyze the influence of electrode parameters on the charging performance and identify the optimal parameter combination. Finally, feasibility and efficiency evaluation experiments were conducted on the designed electrostatic nozzle. The experimental results demonstrate that cross-sectional dimensions of the electrode exhibit a positive correlation with the surface charge density of the pesticide liquid film. In addition, optimal charging performance is obtained when the electrode plane coincides with the tangent plane of the liquid film leading edge. Based on these charging laws, the optimal electrode parameters were determined as follows: 2.0 × 2.0 mm cross-section with an electrode-to-nozzle tip distance of 3.8 mm. With these parameters, the nozzle achieved a droplet charge-to-mass ratio of 4.9 mC/kg at a charging voltage of 3.0 kV. These charged droplets achieved deposition coverages of 12.19%, 5.72%, and 5.91% on abaxial leaf surfaces in the upper, middle, and lower soybean canopies, respectively, which is a significant improvement in deposition uniformity. This study designed a novel air-assisted hollow-cone electrostatic nozzle, elucidated the optimization principles for annular induction electrodes, and achieved improved spraying performance. The findings contribute to enhanced pesticide application efficiency in crops, providing valuable theoretical guidance and technical references for electrostatic nozzle design and application. Full article

Background: The association between diabetes and periodontal disease is well established, but its impact on intrabony periodontal defects remains unclear. Aims: This study examines the relationship between diabetes and intrabony periodontal defects using cone beam computed tomography (CBCT). Methods: A retrospective analysis of 99 CBCT images from Imam Abdurrahman bin Faisal University (2010–2022) was conducted. Intrabony periodontal defects were assessed, and logistic regression was used to analyze their association with diabetes. Results: Intrabony periodontal defects were detected in 66% of the sample, with 36% exhibiting multiple defects. Crude logistic regression showed a significant association between diabetes and intrabony periodontal defects (OR 3.986, 95% CI 1.454–10.922) and defect count (OR 3.382, 95% CI 1.430–8.003). However, multiple regression analysis did not confirm diabetes as an independent predictor (adjusted OR 0.740, 95% CI 0.087–6.314). Conclusions: Diabetes was not significantly associated with the prevalence or number of intrabony periodontal defects after adjusting for the confounders. However, these findings highlight the multifactorial nature of periodontal bone loss and the need for comprehensive patient assessment. Clinically, this underscores the importance of integrating both systemic and local periodontal evaluations in diabetic patients to improve early detection and personalized treatment planning. Further research with larger, more diverse samples and integrated clinical assessments is needed to refine our understanding of this relationship and enhance patient management. Full article

Background/Objectives: Orthodontic temporary anchorage devices (TADs) in the lateral maxillary region are useful tools for successful orthodontic treatment. Radiological anatomical knowledge is crucial for the successful placement of TADs. The use of cone-beam computed tomography (CBCT) is essential for evaluating the relationship between the ideal placement point (IPP) and dental structures, particularly in cases with anatomical limitations. Accordingly, this study aims to assess the anatomical conditions for orthodontic mini-implant (MI) insertion in the posterior maxilla using CBCT as the gold standard. Methods: This retrospective study included 62 patients (37.1% male, 62.9% female) aged 11 to 50 years. CBCT scans (sagittal and axial cross-sections) were used to evaluate interdental bone characteristics in different regions. The evaluated regions were defined as follows: Region 1 (canine and first premolar), Region 2 (first and second premolars), Region 3 (second premolar and first molar), and Region 4 (first and second molars). All parameters were assessed at three predefined levels: A, B, and C, located 4, 3, and 2 mm, respectively, from the alveolar crest. At the aforementioned levels, we performed measurements, such as the interdental width (IDW) in the mesiodistal direction and buccopalatal depth (BPD). The last observation was the relationship between the ideal TAD placement point (IPP) and dental structures, such as contact points (CPs) and cusp tips (C1-cusp of mesial tooth, C2-cusp of distal tooth, in each region). Results: A statistically significant positive correlation was found between the IDW and BPD at Levels A, B, and C in Region 1, while a negative correlation was observed between the IDW and BPD at Level C in Region 2′. The highest percentages of IDW exceeding 3 mm were found in Region 4 at Level A (67.7%), followed by Region 1′ and 2′, both at Level A. The mean interdental width measured at each level on the right and left sides was highest at Level A, exceeding 3 mm, and the width decreased with each successive level. The mean BPD measured at each level on the right and left sides was also highest at Level A. Conclusions: This methodological approach could assist in ensuring precise and efficient implant insertion. Furthermore, it can be concluded that the safe zone for buccal and interdental mini-implant placement is located 4 mm from the alveolar crest at Level A. Also, the CBCT analysis algorithm may serve as a valuable tool for clinicians in determining optimal TAD placement in different dental regions. Full article

Boron neutron capture therapy (BNCT) is a specialized cancer treatment that leverages the high absorption cross-section of boron for thermal neutrons. When boron captures neutrons, it undergoes a nuclear reaction that produces alpha particles and lithium ions, which have high linear energy transfer (LET) and can effectively damage nearby cancer cells while minimizing harm to surrounding healthy tissues. This targeted approach makes BNCT particularly advantageous for treating tumors situated in sensitive areas where traditional radiation therapies may pose risks to critical structures. In this study, the deuterium–deuterium (DD) neutron generator, specifically the DD-110 model (neutron yield Y = 1 × 10¹⁰ n/s), served as the neutron source for BNCT. The fast neutrons produced by this generator were thermalized to the epithermal energy range using a beam-shaping assembly (BSA). The BSA was designed with a moderator composed of 32 cm of MgF₂, a reflector made of 76 cm of Pb, and filters including 3 cm of Pb and 1.52 cm of Bi. A collimator, featuring a 10 cm high Pb cone frustum with a 12 cm aperture diameter, was also employed to optimize beam characteristics. The entire system’s performance was modeled and simulated using the MCNPX code, focusing on parameters both in-air and in-phantom to evaluate its efficacy. The findings indicated that the BSA configuration yielded an optimal thermal-to-epithermal flux ratio (${\phi }_{ther}$/${\phi }_{epth}$) of 0.19, a current-to-flux ratio of 0.87, and a gamma dose-to-epithermal flux ratio of 1.71 × 10⁻¹³ Gy/cm², all aligning with IAEA recommendations. The simulated system showed acceptable ratios for ${\phi }_{ther}$/${\phi }_{epth}$, gamma dose to epithermal flux, and beam collimation. Notably, the advantage depth was recorded at 5.5 cm, with an advantage ratio of 2.29 and an advantage depth dose rate of 4.1 × 10⁻⁴ Gy.Eq/min. The epithermal neutron flux of D110 exceeded D109, but D110’s fast neutron contamination increased ~6.6 times. On the other hand, D110’s gamma contamination decreased by 30%. Based on these findings, optimizing neutron source characteristics is crucial for BNCT efficacy. Future research should focus on developing advanced neutron generators that balance these factors, aiming to produce optimal neutron yields for enhanced treatment outcomes and broader applicability. Full article

This study investigated the historical Kabasakal Mosque minaret’s seismic performance in the Şahinbey district of Gaziantep province. After the 6 February 2023 Kahramanmaraş earthquake, the cone and honeycomb sections of the minaret were damaged. The minaret is a typical masonry structure with a cylindrical body and open balconies belonging to the Ottoman period, and the damage that occurred primarily in the weak areas, such as the honeycomb and the cone, caused serious structural problems due to the earthquakes. In the study, a finite element model (FEM) of the minaret was created. Nonlinear time-history analyses were performed using earthquake records recorded in the district where the minaret is located in the finite element model. First, the original state of the minaret (OM model) was analyzed, and its collapse mechanisms were investigated. Then, a proposal was developed to strengthen the minaret’s honeycomb and cone sections with steel rings. This reinforcement was tested with numerical analyses, and the dynamic performances of both the original and reinforcement models were compared. The durability and seismic performance of local materials commonly used in regional structures, such as Urfa stone, were evaluated. It was observed that the proposed reinforcement method reduced the displacement demands in critical areas and increased the overall rigidity of the structure. The study emphasizes the importance of reinforcement methods in protecting historical structures and reveals the proposed solution’s applicability to similar structures. Full article

Background/Objectives: C-shaped canals represent a challenge in endodontic procedures. The present study aimed to investigate the prevalence and characteristics of C-shaped canals in mandibular second molars in Guayaquil, Ecuador. Methods: CBCT records from two radiology centers were examined (2020–2022). A total of 400 CBCT scans (800 mandibular second molars) were analyzed using Fan’s classification. Data on the presence or absence of C-shaped canals, gender, and bilateral occurrence were collected. Statistical analysis included the test for differences in proportions and the chi-squared test to assess the significance of correlations between variables. Results: C-shaped canals were found in 28% of mandibular second molars, affecting 33.75% of the patient sample. The prevalence was significantly higher in females (42.9%) compared to males (20.4%). Bilateral occurrences were observed in 63% of affected patients. Morphologic variability was pronounced, with Fan C1 and C4 dominating in the coronal and apical thirds, respectively, while a shift toward Fan C2 and C3 was observed in the middle third. Only 19.2% of the teeth maintained a consistent morphology. Conclusions: C-shaped canals were found in 28% of mandibular second molars and occurred predominantly in females. Notably, most cases were bilateral, highlighting the importance of effectively adapting endodontic techniques to treat this unique anatomical variation. Further research into genetic and environmental influences could deepen our understanding and help develop refined diagnostic and therapeutic strategies. Full article

Background: One of the parameters of maximum interest regarding the quality of the intraoral hard tissues is represented by the bone density, with direct clinical implications. The evaluation of this extremely important clinical parameter can be achieved by several imaging methods, of which the most known in dentistry is represented by the cone beam computed tomography (CBCT). Objectives: The purpose of the study is to obtain a quantitative analysis of bone mineral density changes in patients who underwent treatments of photobiomodulation (PBM), as complementary to a surgical approach in oral surgery and implantology. Methods: The study included the retrospective analysis of maxillary cone beam computed tomography of 28 patients without pathology or medication known to affect bone metabolism or its qualitative and quantitative properties. All patients from the study group followed the same laser PBM treatment protocol after placing dental implants; the PBM protocol implied the intraoral use of a gallium aluminum arsenide laser (GaAlAs) of 808 nm, 450 mW, in pulsed mode, administering an energy of 6 J in 3 points corresponding to each inserted dental implant—mesial, distal, and apical—totaling 18 J/implant. Treatment sessions were performed immediately postoperatively and at a subsequent distance of 48 h for 2 weeks (a total of eight sessions). For every patient, bone density was analyzed before and after PBM treatment, in the same areas of interest, within the same anatomical landmarks. A comparison was also made between the results obtained for the anterior maxilla and the posterior maxilla. All the measurements made were analyzed statistically, the results being presented in the dedicated section. Results: Based on the data analysis, the comparison between the lasered and non-lasered groups reveals that patients who underwent PBM showed a statistically significant improvement in bone mineral density, with the mean increasing from 530.91 HU before treatment to 842.55 HU after treatment (t-test: p < 0.001). In contrast, the non-lasered group showed no significant improvement, with a slight decrease in bone mineral density, as the mean dropped from 495.19 HU before treatment to 462.16 HU after treatment (t-test: p = 0.47). Conclusions: The study demonstrated results with statistical significance regarding the mineral bone density improvement of patients who underwent laser PBM treatment. This positive effect of laser therapy has been shown, both at the level of the vestibular cortical bone and at level of the trabecular bone, independent of the patient’s sex, for the anterior maxilla and at the lateral areas also. Full article

Background/Objectives: Clinical photography is an essential component of orthodontic records, alongside radiographs, dental scanners, and cone beam computed tomography. However, neither the American Association of Orthodontists nor the Spanish Society of Orthodontics provides a standardized protocol for dental photography. This study aimed to evaluate the current practices, challenges, and training needs related to clinical photography among orthodontists in Spain. Methods: A cross-sectional survey was designed using Google Forms^® and distributed to orthodontists practising in Spain. A sample size of 303 participants was calculated (95% confidence level; 0.1 precision). The questionnaire covered photographic practices, equipment usage, self-assessed skills, interest in training, and legal considerations. Descriptive and inferential analyses were performed using R software (significance level 0.05; version 4.4.1). Results: A total of 304 valid responses were analyzed, with a predominance of female participants (77.96%) and a mean age of 37.54 years (SD: 9.08). Digital single-lens reflex (DSLR) cameras with macro lenses and ring flashes were the most used equipment (68.09%). The primary software for cropping and editing images were Windows Photos (28.95%) and MacOS Photos (16.12%). Male participants rated their photography skills higher than female participants (p = 0.003), and those with full-time orthodontic training considered their skills better than those with other types of training (p = 0.014). Photography was most valued for diagnosis in the exclusive orthodontics group (p = 0.019). Additionally, 75.99% of respondents expressed interest in improving their photography skills through specialized courses. Conclusions: This study highlights significant variability in photographic practices among orthodontists in Spain. The findings emphasize the need for standardized photography protocols to enhance diagnostic accuracy, clinical documentation, and professional training. Full article