Dento maxillo facial radiology最新文献

Objective: This work aimed to detect automatically periapical lesion on panoramic radiographs (PRs) using deep learning.

Methods: 454 objects in 357 PRs were anonymized and manually labeled. They are then pre-processed to improve image quality and enhancement purposes. The data were randomly assigned into the training, validation, and test folders with ratios of 0.8, 0.1, and 0.1, respectively. The state-of-art 10 different deep learning-based detection frameworks including various backbones were applied to periapical lesion detection problem. Model performances were evaluated by mean average precision, accuracy, precision, recall, F1 score, precision-recall curves, area under curve and several other Common Objects in Context detection evaluation metrics.

Results: Deep learning-based detection frameworks were generally successful in detecting periapical lesions on PRs. Detection performance, mean average precision, varied between 0.832 and 0.953 while accuracy was between 0.673 and 0.812 for all models. F1 score was between 0.8 and 0.895. RetinaNet performed the best detection performance, similarly Adaptive Training Sample Selection provided F1 score of 0.895 as highest value. Testing with external data supported our findings.

Conclusion: This work showed that deep learning models can reliably detect periapical lesions on PRs. Artificial intelligence-based on deep learning tools are revolutionizing dental healthcare and can help both clinicians and dental healthcare system.

Objectives: The purpose of this study was to evaluate the association between clinical manifestations of occlusal trauma of the teeth and maximum signal intensity of periodontal ligament space on MRI.

Methods: 20 subjects (males: 9, females: 11, mean age: 35.9 ± 14.0 years, range: 22-65 years) participated in this study. Subjective symptoms of bruxism, tooth mobility, fremitus, occlusal contact area, occlusal force, widening of the periodontal ligament space, and thickening of the lamina dura were defined as clinical manifestations of occlusal trauma. The total number of clinical manifestations was used to evaluate the degree of clinical occlusal trauma, with a score of 7 indicating the highest degree of occlusal trauma. The maximum signal intensity in the periodontal ligament space was evaluated by a specific T₂ weighted MRI sequence: IDEAL image.

Results: Spearman's rank correlation between the total clinical occlusal trauma score and maximum signal intensity in the periodontal ligament space was 0.529 for all teeth, 0.517 for anterior teeth, and 0.396 for molar teeth (p < 0.001 for all).

Conclusions: A significant correlation between the degree of occlusal trauma and the signal intensity of the periodontal ligament space suggests a new potential MRI-based method for objectively determining occlusal trauma.

Objectives: To identify clinical and tomographic prognostic factors for conservative and surgical treatment of medication-related osteonecrosis of the jaws (MRONJ).

Methods: A retrospective search identified patients treated with antiresorptive drugs (ARDs), diagnosed with Stage 1, 2 or 3 MRONJ, and having CBCT scans previous to conservative or surgical treatment. Following data collection, imaging assessment of the following parameters on each MRONJ site was performed: involvement of teeth and/or implants, presence of osteosclerosis, osteolysis, sequestrum formation, periosteal reaction, and pathological fractures. For statistical analysis, patients and lesions were divided into conservative and surgical treatment. Comparisons were made between successful and unsuccessful outcomes. Significance was set at p ≤ 0.05.

Results: 115 ARD-treated patients who developed 143 osteonecrosis lesions were selected. 40 patients and 58 lesions received conservative treatment, of which 14 patients (35%) and 25 lesions (43%) healed. Additionally, 75 patients and 85 lesions underwent surgery, with 48 patients (64%) and 55 lesions (65%) that healed. Clinical and tomographic risk factors for conservative treatment were MRONJ staging, tooth involvement, extensive osteosclerosis, and deep sequestrum formation (p < 0.05). Complementarily, poor prognostic indicators for surgical therapy were a short bisphosphonate (BP) holiday, MRONJ staging, absence of sequestrum formation, and presence of periosteal reaction (p < 0.05).

Conclusions: Lesions at Stage 3 MRONJ, with tooth involvement, or sequestrum formation showed poor outcomes when conservative treatment is chosen. Alternatively, surgical treatment is most effective when BPs are discontinued, in Stage 1 lesions, in the presence of sequestrum formation, and absence of periosteal reaction.

Objectives: To assess the effect of standard filtered back projection (FBP) and iterative reconstruction (IR) methods on CBCT image noise and processing time (PT), acquired with various acquisition parameters with and without metal artefact reduction (MAR).

Methods: CBCT scans using the Midmark EIOS unit of a human mandible embedded in soft tissue equivalent material with and without the presence of an implant at mandibular first molar region were acquired at various acquisition settings (milliamperages [4mA-14mA], FOV [5 × 5, 6 × 8, 9 × 10 cm], and resolutions [low, standard, high] and reconstructed using standard FBP and IR, and with and without MAR. The processing time was recorded for each reconstruction. ImageJ was used to analyze specific axial images. Radial transaxial fiducial lines were created relative to the implant site. Standard deviations of the gray density values (image noise) were calculated at fixed distances on the fiducial lines on the buccal and lingual aspects at specific axial levels, and mean values for FBP and IR were compared using paired t-tests. Significance was defined as p < 0.05.

Results: The overall mean for image noise (± SD) for FBP was 198.65 ± 55.58 and 99.84 ± 16.28 for IR. IR significantly decreased image noise compared to FBP at all acquisition parameters (p < 0.05). Noise reduction among different scanning protocols ranged between 29.7% (5 × 5 cm FOV) and 58.1% (5mA). IR increased processing time by an average of 35.1 s.

Conclusions: IR significantly reduces CBCT image noise compared to standard FBP without substantially increasing processing time.

Objectives: To assess the distortion of high-density materials using two CBCT devices presenting convex triangular and cylindrical fields of view (FOVs).

Methods and materials: Four high-density cylinders were individually placed in a polymethylmethacrylate phantom. 192 CBCT scans were acquired using the convex triangular and cylindrical FOVs of Veraviewepocs^® R100 (R100) and Veraview^® X800 (X800) devices. Using Horos^TM's software, two oral radiologists determined the cylinders' horizontal and vertical dimensional alterations. Nine oral radiologists subjectively identified each cylinder's axial shape distortion. Statistical analysis comprised Multiway ANOVA (α = 5%), and the Kruskal-Wallis test.

Results: The distortion in the axial plane was greater in the convex triangular FOVs for both devices in almost all the materials (p < 0.05). The evaluators subjectively identified a shape distortion in both FOVs for R100 device (p < 0.001), while no distortion was identified for X800 device (p = 0.620). A vertical magnification of all materials was observed in both FOVs for both devices (p < 0.05). No differences among vertical regions (p = 0.988) nor FOVs (p = 0.544) were found for the R100 device, while all materials showed higher magnification in all regions in the cylindrical FOV (p < 0.001) of the X800 device.

Conclusions: The convex triangular FOV influenced the axial distortion of the high-density materials in both devices. A vertical magnification was observed in both FOVs of both devices, but it was greater in the cylindrical FOV of the X800 device.

Objective: To develop a novel technique for localizing and reconstructing the greater palatine artery (GPA) using three-dimensional (3D) technology.

Methods: A miniaturized intraoral ultrasound transducer was used to imaging landmarks including the GPA, gingival margin (GM), and palatal masticatory mucosa (PMM). A 5-mm-thick solid hydrogel couplant was integrated to replace traditional ultrasound gel and avoid bubbles when moving the transducer.

Results: A panorama image provided the relative localization of landmarks including the GPA, PMM, and hard palate. Short- and long-axis imaging of GPA was performed in five subjects including 3D mapping of GPA branches and surrounding tissues in a volume of 10 mm × 8 mm × 10 mm. Full-mouth Doppler imaging was also demonstrated on both the dorsal and ventral tongue as well as buccal mucosa and sublingual region on two subjects.

Conclusions: This study can measure the vertical distance from the GM to the GPA and depth from PMM to GPA and visualize the GPA localization in a 3D manner, which is critical to evaluate the available volume of palatal donor tissues and avoid sectioning of GPA during surgical harvesting of the tissues. Finally, the transducer's small size facilitates full-mouth Doppler imaging with the potential to improve the assessment, diagnosis, and management of oral mucosa.

Objectives: Arrested pneumatisation (AP) is an anatomic variant of the sphenoid sinus. Since AP remains underrecognised, otolaryngologists and radiologists may mistake AP for a lesion and perform follow-up imaging studies. We investigated the imaging findings of CT, MRI, and F-18 fludeoxyglucose (FDG)-positron emission tomography (PET) for AP, and discussed the differences between AP and other skull base lesions.

Methods: We reviewed multidetector low CT imaging of 442 patients (285 men and 157 women; age range, 19-93 years; mean age, 67.8 years) who underwent FDG-PET/CT for head and neck tumours between January 2019 and December 2019. The imaging findings of AP were reviewed on CT, MRI, FDG-PET/CT, and compared with those of fibrous dysplasia, chordoma, chondrosarcoma, multiple myeloma, and bone invasion of nasopharyngeal carcinoma.

Results: AP was identified in 22 patients (14 men and 8 women; age range, 24-93 years; mean age, 67.0 years) based on criteria from previous reports. AP manifested with well-circumscribed sclerotic margins on CT, without evidence of expansion. AP showed high-signal intensity on T₁-/T₂ weighted MRI. FDG-PET revealed non-significant uptake [maximum standardised uptake value (SUV_max): 0.85 (range, 0.4-1.27)] in AP. Contrastingly, skull base lesions showed expansion, poorly circumscribed boundaries without osteosclerotic margins, and moderate-to-severe FDG uptake (SUV_max: 1.8-8.4).

Conclusions: The characteristic imaging findings of AP, namely non-expansile on CT and non-uptake on FDG-PET, may aid in its differentiation from other skull base lesions.

Objectives: To evaluate the reliability and reproducibility of an artificial intelligence (AI) software in identifying cephalometric points on lateral cephalometric radiographs considering four settings of brightness and contrast.

Methods and materials: Brightness and contrast of 30 lateral cephalometric radiographs were adjusted into four different settings. Then, the control examiner (ECont), the calibrated examiner (ECal), and the CEFBOT AI software (AIs) each marked 19 cephalometric points on all radiographs. Reliability was assessed with a second analysis of the radiographs 15 days after the first one. Statistical significance was set at p < 0.05.

Results: Reliability of landmark identification was excellent for the human examiners and the AIs regardless of the type of brightness and contrast setting (mean intraclass correlation coefficient >0.89). When ECont and ECal were compared for reproducibility, there were more cephalometric points with significant differences on the x-axis of the image with the highest contrast and the lowest brightness, namely N(p = 0.033), S(p = 0.030), Po(p < 0.001), and Pog'(p = 0.012). Between ECont and AIs, there were more cephalometric points with significant differences on the image with the highest contrast and the lowest brightness, namely N(p = 0.034), Or(p = 0.048), Po(p < 0.001), A(p = 0.042), Pog'(p = 0.004), Ll(p = 0.005), Ul(p < 0.001), and Sn(p = 0.001).

Conclusions: While the reliability of the AIs for cephalometric landmark identification was rated as excellent, low brightness and high contrast seemed to affect its reproducibility. The experienced human examiner, on the other hand, did not show such faulty reproducibility; therefore, the AIs used in this study is an excellent auxiliary tool for cephalometric analysis, but still depends on human supervision to be clinically reliable.

Objectives: To investigate the accuracy of fused CBCT images in diagnosing three distinct groups of bone changes characterized by volume and thickness decrease in patients with temporomandibular joint osteoarthrosis (TMJ OA) during follow-up.

Methods: In this retrospective study, 109 patients (176 TMJs) with TMJ OA were included. Two consecutive CBCT images for the same patient were registered and fused. Then, three image sets were established: without fusion, fused 2D image, and fused 3D image. Three residents randomly and independently evaluated whether there was condylar resorption with the three image sets respectively. The samples diagnosed as condylar resorption by the expert panel were divided into three subgroups according to the volume and thickness decrease calculated after segmentation. The inter- and intraobserver agreement, receiver operating characteristic (ROC), and area under the curve (AUC) evaluated the diagnostic capability for different subgroups.

Results: For the volume decrease more than 50 mm³ and thickness decrease more than 1 mm groups, the AUC values for fused image sets were higher than those without fusion (p < 0.01). For the volume decrease within 50 mm³ and thickness decrease within 1 mm groups, the AUC values for fused 2D image sets were higher than the image sets without fusion (p < 0.05), but there was no significant difference between the fused 3D image sets and the image sets without fusion (p = 0.48 for volume decrease, p = 0.37 for thickness decrease).

Conclusions: The fused images can improve the diagnostic accuracy and repeatability for the samples with at least 50 mm³ volume decrease or 1 mm thickness decrease compared with the image groups without fusion.

Objectives: Early pre-clinical inflammatory changes in periodontal and/or periapical lesions, which typically precede bone loss, are challenging to diagnose using ionizing-radiation-based imaging modalities. MRI provides relevant additional diagnostic information of inflammatory processes in soft and hard tissues. The aim of the present study is to undertake a systematic review of the literature on MRI in the diagnosis of periodontal and/or periapical disease.

Methods and materials: The PubMed/MEDLINE and Scopus bibliographic databases were searched (2000-2021) using the search string: ("MRI" or "magnetic resonance imaging") and ("periodontitis" or "periodontal" or "apical pathology" or "endodontic pathology" or "periapical" or "furcation" or "intrabony"). The search was limited to studies published in English. The studies were assessed independently by three reviewers, focusing on the MRI sequences, imaging modalities (radiographs, cone beam CT (CBCT), and MRI), disease definition, assessed parameters, and outcome measurements.

Results: The search strategy yielded 34 studies, from which 13 were included. Overall, the findings of MRI were in agreement with CBCT. The studies showed that MRI provided diagnostic information of the hard and soft tissue components affected by periodontal and/or periapical disease with a fairly high sensitivity and specificity. However, the assessed parameters (e.g. MRI acquisition protocols, and disease definition) differed substantially.

Conclusions: The included studies indicate that the use of MRI in the diagnosis of periodontal and/or periapical disease is feasible and promising. More studies are needed to define the accuracy of this non-ionizing-radiation-based diagnostic modality, in the assessment of periodontal and/or periapical lesions.