Dento maxillo facial radiology最新文献

Objectives: To evaluate the impact of ambient exposure of photostimulable phosphor (PSP) plates and digital enhancement on detecting internal root resorption (IRR).

Methods: Thirty-five single-rooted teeth were selected, including 15 with artificially induced IRR (via 3-hour immersion in 37% hydrochloric acid) and 20 controls. Three repeated periapical radiographs were acquired of each tooth using the parallelling technique and PSP plates from the Express, VistaScan Mini, and CS 7600 digital radiographic imaging systems. For each set of 3 X-ray exposures, prior to scanning, one PSP plate was kept shielded from ambient light, another was exposed to ambient light for 5 seconds, while the third was exposed for 10 seconds. The presence of IRR in the total sample of 315 radiographs was assessed by 4 independent examiners using a 5-point scale. Initially, digital enhancement was not allowed, and these images were considered originals. A second round was conducted with adjustments permitted (enhanced radiographs). Sensitivity, specificity, and area under the receiver operating characteristic curve were calculated and compared using 2-way analysis of variance (α = 0.05).

Results: No significant differences were found among different light exposure times across all systems (P > .05). In the CS 7600, enhanced radiographs showed significantly higher sensitivity and lower specificity compared to originals (P < .05).

Conclusions: Ambient light exposure of PSP for up to 10 seconds does not compromise IRR diagnosis. Digital enhancement in CS 7600 may increase detection but reduce specificity, requiring cautious interpretation to avoid overdiagnosis.

Objectives: This study aimed to evaluate the diagnostic ability of relative values of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) and diffusion kurtosis imaging (DKI) quantitative parameters for salivary gland tumours (SGTs).

Methods: A total of 107 patients with histopathologically confirmed SGTs (18 malignant [MTs], 38 pleomorphic adenomas [PAs], 31 Warthin tumours [WTs], 20 basal cell adenomas [BCAs]) underwent MRI with DKI and DCE-MRI sequences. Quantitative parameters included DCE-MRI-derived volume transfer constant (Ktrans), rate constant (Kep), fractional volume of the extravascular-extracellular space (Ve), plasma fraction (Vp), and DKI-derived mean kurtosis (MK) and mean diffusion (MD).The receiver operating characteristic (ROC) curve were used for statistical analysis. Statistical significance was set at P < 0.05.

Results: PAs exhibited the lowest MK (0.49 ± 0.15) among all groups (P < 0.05). Compared to WTs, PAs showed lower Kep (366.89 [260.06, 568.32]×10-³ min-1), higher MD (2.02 ± 0.42 × 10-³ mm2/s), and higher Ve (551.83 [388.10, 883.19]×10-³). PAs also displayed higher Ve, lower Kep, and lower Vp (85.42 [20.53, 332.72])×10-³) than BCAs, and lower Vp with higher Ve than MTs (all P < 0.05). WTs had significantly lower Ve (218.86 [142.07, 341.76]×10-³) than MTs (P = 0.001). BCAs demonstrated lower MK (0.61 ± 0.23) and higher MD (1.97 ± 0.44 × 10-³ mm2/s) compared to WTs and MTs (P < 0.05), alongside lower Ktrans (355.25 [211.88, 506.92]×10-³ min-1) and Ve (380.89 [271.28, 589.53]×10-³) than WTs (P < 0.05). Logistic regression analysis revealed enhanced discrimination: MK+Ve (AUC = 0.895) and MK + MD + Ve + Kep (AUC = 0.936) differentiated PAs from WTs; Kep + Vp + Ve distinguished PAs from BCAs (AUC = 0.843); MD + MK + Vp separated PAs from MTs (AUC = 0.854); Ktrans + MK differentiated WTs from BCAs (AUC = 0.856).

Conclusions: DKI and DCE-MRI parameters complement each other, enabling accurate SGT subtype differentiation. Combined use of these parameters achieves high diagnostic accuracy, and a stepwise diagnostic flowchart was designed to facilitate systematic discrimination among the four tumour types.

Objectives: To compare the measurement accuracy of cone-beam computed tomography (CBCT), high-resolution ultrasound (US), and intraoral scanning (IOS) with the gold-standard direct method in the measurement of peri-implant bone defects.

Methods: Forty standard-threaded and thirty-eight aggressive-threaded (Aggressor®) implants-identical in diameter and length (4.3/10 mm) but differing in macro-thread design-were placed into bovine rib bones in vitro. Dehiscence, 2/3-wall, and 4-wall (circumferential) defects were prepared around the implants. Each defect was measured for maximum width, depth, and height using CBCT, US, IOS, and direct manual measurement. Analyses were performed using the General Linear Model (ANOVA). A p-value < 0.05 was considered statistically significant.

Results: Intra-operator and inter-operator agreement showed high reliability (Gage R&R below 10%). For maximum width, defect type (F = 894.81, p < 0.001), method (F = 6.76, p < 0.001), and implant type (F = 5.39, p = 0.021) were significant. For maximum depth, defect type (F = 861.12, p < 0.001) and method (F = 3.39, p = 0.018) were significant. For maximum height, method (F = 12.62, p < 0.001) and defect type (F = 38.91, p < 0.001) were significant. The model demonstrated high explanatory power for width (R2=75.9%) and depth (R2=76.6%) measurements but lower for height (R2=20.7%). CBCT provided the most consistent results relative to direct measurements, followed by US, whereas IOS showed greater deviations.

Conclusions: CBCT showed the highest agreement with direct measurements, followed by US, while IOS exhibited greater variability. Defect type and measurement modality were the primary determinants of accuracy. These findings indicate that CBCT and US can be considered reliable tools for assessing peri-implant bone defects.

Objective: Radiation exposure remains a major concern in dentomaxillofacial imaging, especially for children and young adults who require repeated examinations. A precise, non-ionizing alternative for craniofacial measurement would have significant implications for clinical practice. Computed tomography (CT) and cephalometry are widely used but expose patients to ionizing radiation. Zero Echo Time Magnetic Resonance Imaging (ZTE-MRI) enable to visualize short-T2 tissues, including cortical bone, without radiation by minimizing TE toward zero; however, clinical head-and-neck use has been limited. The goal of the present study was to investigate the possibility of performing precise three-dimensional measurements of the craniofacial regions using ZTE-MRI.

Materials and methods: Twenty-nine participants (mean age 32.14±17.09 years; 23 female, 6 male) underwent MDCT and ZTE-MRI. Standard cephalometric landmarks were identified, yielding 27 linear and 21 angular variables. For each variable, linear regression analysis was performed for the results on MDCT (Multi-Detector CT) images and ZTE-MRI.

Results: Nineteen linear and eight angular variables had regression coefficients between 0.9 and 1.1 and 28 of the linear and 16 of the angular variables had R-square values of 0.81 or higher. 25 linear and 16 angular variables showed Cohen's effect sizes within the ±0.8 range.

Conclusions: Variables derived from skeletal reference points showed clinically acceptable results, indicating that ZTE-MRI is useful for these measurements. In contrast, variables involving dental reference points demonstrated lower agreement, making accurate measurement in these regions difficult.

Advances in knowledge: To our knowledge, this study is the first to show that ZTE-MRI allows feasible linear and angular craniofacial measurements used in dental practice and demonstrates good agreement with MDCT for major skeletal landmarks. These findings support its potential future clinical applicability for radiation-free bone assessment; however, further research is warranted to establish its performance across all measurements.

Objectives: This study aimed to analyze the correlation between disc position and condylar position and morphology through fused cone-beam computed tomography (CBCT) and magnetic resonance (MR) images.

Methods: Patients exhibiting temporomandibular disorder symptoms were included, and joints with poor osseous consistence were excluded. Angle of disc was measured in the fused image using the method proposed in this study. Joint spaces were measured, and condylar morphology was assessed in cone-beam computed tomography images. Statistical analysis was performed to examine the reliability of measurement method and the correlation between disc position and condylar position/morphology. A logistic regression model was used for identifying factors associated with anterior disc displacement.

Results: Our results showed that inter- and intra-observer agreement for measurements of disc angle and joint space were excellent (Intraclass correlation coefficient >0.9). Superior joint space, posterior joint space, and natural logarithm of the posterior-to-anterior joint space ratio showed significant correlations with the angle (P < 0.01) and significant differences between groups (P < 0.01). The posterior-to-anterior joint space ratio was significantly smaller in the mild displacement group. The logistic regression model demonstrated that beak-like shape in oblique sagittal view (OR = 5.235, P < 0.05) and reduced posterior-to-anterior ratio (OR = 0.301, P < 0.05) significantly increased the risk of anterior disc displacement.

Conclusions: Condylar position and morphology demonstrated statistically significant association with disc position. Multivariate logistic regression analysis revealed that condylar position and morphology in sagittal views in cone-beam computed tomography images can serve as indicators for disc displacement.

Objectives: Federated learning (FL) may mitigate privacy constraints, heterogeneous data quality, and inconsistent labeling in dental diagnostic artificial intelligence (AI). FL was compared with centralized (CL) and local learning (LL) for tooth segmentation in panoramic radiographs across multiple data corruption scenarios.

Methods: An Attention U-Net was trained on 2066 radiographs from six institutions across four settings: baseline (unaltered data); label manipulation (dilated/missing annotations); image-quality manipulation (additive Gaussian noise); and exclusion of one faulty client with corrupted data. FL was implemented via the Flower AI framework. Per-client training- and validation loss trajectories were monitored for anomaly detection and a set of metrics (Dice, IoU, HD, HD95 and ASSD) were evaluated on a hold-out test set. From these metrics significance results were reported through Wilcoxon signed-rank test. CL and LL served as comparators.

Results: Baseline: FL achieved a median Dice of 0.94889 (ASSD: 1.33229), slightly better than CL at 0.94706 (ASSD: 1.37074) and LL at 0.93557-0.94026 (ASSD: 1.51910-1.69777). Label manipulation: FL maintained the best median Dice score at 0.94884 (ASSD: 1.46487) versus CL's 0.94183 (ASSD: 1.75738) and LL's 0.93003-0.94026 (ASSD: 1.51910-2.11462). Similar performance was observed when two faulty clients were introduced. Image noise: FL led with Dice at 0.94853 (ASSD: 1.31088); CL scored 0.94787 (ASSD: 1.36131); LL ranged from 0.93179-0.94026 (ASSD: 1.51910-1.77350). Similar performance was observed when two faulty clients were introduced, with CL performing slightly better than FL. Faulty-client exclusion: FL reached Dice at 0.94790 (ASSD: 1.33113) better than CL's 0.94550 (ASSD: 1.39318). Loss-curve monitoring reliably flagged the corrupted site.

Conclusions: FL matches or exceeds CL and outperforms LL across corruption scenarios while preserving privacy. Per-client loss trajectories provide an effective anomaly-detection mechanism and support FL as a practical, privacy-preserving approach for scalable clinical AI deployment.

Objectives: This study aimed to assess whether texture feature maps (TFMs) derived from CBCT images improve the detection of small simulated condylar defects and to examine the influence of voxel size.

Methods: Eight dry mandibles received three spherical defects (0.9, 1.0, 1.2 mm) in each condyle. CBCT scans were performed at voxel sizes of 0.20 mm and 0.40 mm. Sagittal and coronal slices were exported and processed in MaZda software to generate GLCM-based texture maps (contrast, entropy, etc). Three experienced radiologists independently evaluated randomized images for the presence of cortical defects. Kappa, McNemar, and Fisher tests (α = 0.05) were used.

Results: Contrast-based TFMs yielded the highest diagnostic performance, with Kappa values ranging from 0.78-1.00 and significant improvement over unprocessed images (p < 0.05). Entropy maps showed the poorest performance. There was no significant effect of voxel size or defect dimension. TFMs enhanced interobserver agreement.

Conclusions: Texture feature maps, especially based on contrast, may enhance visualization of subtle condylar bone defects independent of voxel size. This post-processing approach could provide a low-dose adjunct to improve CBCT diagnostic confidence in TMJ imaging.

Advances in knowledge: This study introduces the use of texture feature maps in CBCT evaluation of the mandibular condyle, demonstrating that contrast-based mapping enhances detection of subtle bone defects and may support early TMJ diagnosis.

Objectives: Upper airway assessment is crucial due to its impact on craniofacial growth and airway-related disorders. This retrospective observational cross-sectional study aimed to evaluate the upper pharyngeal airway space volume and minimum cross-sectional area in a normal sample from Upper Egypt population, analyzing age and gender-related variations using cone-beam computed tomography.

Methods: Ninety cone beam computed tomography scans of patients aged 18 to 60 years were evaluated. The sample was divided into three groups (Group I: ≤20 years, Group II: 21-40 years, and Group III: >40 years). Each group was further divided into two subgroups according to gender. Nasopharyngeal, oropharyngeal, hypopharyngeal, and total airway volumes, as well as the minimum cross-sectional area, were calculated using Dolphin 3D® software. Two-way ANOVA with Bonferroni post hoc test was used for statistical analysis.

Results: The findings revealed significant gender differences. Males exhibited larger airway dimensions across all age groups except for nasopharyngeal volumes in adults over 20 years. A decline in airway volumes and minimum cross-sectional area in individuals over 40 years. The most constricted airway area predominantly occurred in the oropharynx. A strong positive correlation exists between minimum cross-sectional area and airway volumes. Very good inter- and intra-observer agreement.

Conclusions: Upper pharyngeal airway dimensions in a sample of the Upper Egyptian population are influenced by age and gender, highlighting the need for age and gender specific considerations in the diagnosis and treatment.

Advances in knowledge: This study is the first to evaluate age and gender-related variations in upper pharyngeal airway volume within the Upper Egypt population. Also, it introduces a discriminant model that provides a probabilistic classification of the site of minimum cross-sectional area with 62.2% accuracy.

Objectives: To evaluate image quality of radiographs obtained with photostimulable phosphor (PSP) plates after cleaning with 2% chlorhexidine.

Methods: Eight PSP plates were used: four from Express system and four from VistaScan system. Two plates from each system were wiped with 2% chlorhexidine in aqueous solution (CHX AQ), and the other two plates from each system with 2% chlorhexidine in alcoholic solution (CHX AL). Before cleaning and after every five cleaning cycles (up to 100 cleanings), two radiographs of an acrylic block and two of an aluminum step wedge were acquired with each PSP plate. The image's gray values were measured to assess image brightness, noise, uniformity, and contrast. Two-way repeated measures ANOVA followed by Sidak's post hoc test analyzed the influence of the number of cleanings and substance type on these parameters (α = 0.05).

Results: Considering the number of cleanings, image brightness varied for CHX AL in the Express system and CHX AQ in the VistaScan system, with no consistent pattern (p < 0.05). Noise varied for both substances in the VistaScan system, also without a clear pattern (p < 0.05). In the Express system, regarding the substance type, CHX AL resulted in lower brightness and CHX AQ in lower noise after 75 cleanings (p < 0.05). Contrast and uniformity were not affected by either the number of cleanings or the substance type (p > 0.05). Despite numerical variations in some objective parameters, overall image quality remained stable across all cleanings for both substances. No artefacts were observed in the images.

Conclusion: Regarding image quality, 2% chlorhexidine-whether aqueous or alcohol-based-can be recommended for PSP plates cleaning.

Objective: This review aims to systematically summarize the current studies on the correlation between different degrees of anterior disc displacement (ADD) and temporomandibular joint (TMJ) space.

Materials and methods: Study protocol was carried out based on the preferred reporting items for systematic review and meta-analysis protocols (PRISMA). The PubMed, Scopus, Web of Science and China National Knowledge Infrastructure (CNKI) databases were searched to find the relevant articles from database up to February 13, 2025. Studies that evaluated the correlation between ADD and TMJ spaces were included. We excluded intervention studies, case reports, case series, reviews, systematic reviews, opinion articles, book chapters, and studies involving populations with comorbidities potentially affecting the joints. The risk of bias was assessed using the QUADAS-2 tool.

Results: Of the 1109 articles retrieved, a total of 10 articles on the correlation between different degrees of ADD and TMJ spaces were included after evaluation of the title, abstract, and full text. Throughout different degree of anterior disc displacement (ADD), variations in anterior joint space (AJS) and posterior joint space (PJS) exist due to condyle displacement. When the progresses further to anterior disc displacement without reduction (ADDWoR), the superior joint space (SJS) becomes narrow.

Conclusion: There was a stepwise correlation between the TMJ spaces and the degree of ADD. The AJS and PJS tends to be various in different ADD groups, and the SJS tends to be narrowed in ADDWoR patients. Future studies should standardize methodologies to validate its clinical applicability.