Imaging Science in Dentistry最新文献

Purpose: Physiological dentin sclerosis is a distinctive phenomenon observed in transverse sections of the tooth root as a tooth ages. Since this effect has only been visualized 2-dimensionally, this pilot proof-of-concept study aimed to propose a novel method to visualize and quantify physiological sclerotic dentin 3-dimensionally using density-based micro-computed tomography (CT)-generated gray values.

Materials and methods: Forty single-rooted premolars of known chronological age from the Malay male population were scanned with a micro-CT scanner. The X-ray source was operated at 160 kV, 100 μA, and a voxel size of 48.8 μm. Three-dimensional volume datasets for each tooth were reconstructed, and volumetric analysis was performed on the root dentin region using the open-source software FIJI (ImageJ) (ver. 1.54k, National Institutes of Health, Bethesda, USA).

Results: Micro-CT imaging enabled the selection, isolation, and quantification of high-density areas in the tooth root that correspond to physiological sclerotic dentin. The generated gray value profile also reflected the characteristic butterfly-shaped pattern seen in transverse root sections. A comparison of premolars from different age groups revealed that individuals aged 31-60 years exhibited a larger butterfly-shaped area, reflecting the increase in high-density sclerotic dentin, compared with younger premolars.

Conclusion: In this pilot proof-of-concept study, visualization and measurement of physiological sclerotic dentin were shown to be feasible using micro-CT. However, the method is highly dependent on the capability of the micro-CT scanner and the performance of the image-processing software. Further research is needed to improve image quality using advanced micro-CT scanning techniques.

Purpose: This study compared nasal septum deviation (NSD), nasal deformities, and anterior nasal spine deviation (ANSD) and evaluated their relationships in patients with unilateral cleft lip and palate (UCLP), bilateral cleft lip and palate (BCLP), and no cleft, using cone-beam computed tomography (CBCT).

Materials and methods: A retrospective cross-sectional study was conducted in 98 individuals (43 with UCLP, 33 with BCLP, and 22 non-cleft individuals; aged 8-36 years). CBCT measurements of NSD, nasal morphology, and ANSD were obtained. Group differences and correlations among NSD, nasal deformities, and ANSD were analyzed using 1-way analysis of variance, paired t-tests, chi-square tests, and multinomial logistic regression (P<0.05).

Results: NSD was highly prevalent, affecting approximately 97% of patients with cleft lip and palate and 86% of non-cleft individuals. Cleft type was significantly related to the severity and shape classification of NSD; UCLP was associated with greater severity than BCLP, which was linked to greater severity than in non-cleft individuals. Conversely, age and sex displayed no significant relationships with NSD occurrence. Patients with UCLP exhibited the most pronounced nasal asymmetry and significantly greater ANSD, with deviation toward the non-cleft side consistently observed. In patients with BCLP, NSD and ANSD demonstrated a moderate to substantial positive correlation (r=0.47), although their deviations often occurred in opposite directions.

Conclusion: Patients with BCLP exhibit a comparatively symmetrical nasal appearance; however, the nasolabial area remains affected. Both NSD and ANSD contribute substantially to nasal deformities in patients with cleft lip and palate, particularly those with UCLP.

Purpose: This systematic review aimed to identify, appraise, and synthesize evidence on the diagnostic accuracy of artificial intelligence (AI) algorithms for detecting and classifying furcation defects on radiographic images, addressing limitations of traditional methods.

Materials and methods: A comprehensive search of databases and registers was conducted through April 2025. Inclusion criteria comprised diagnostic accuracy studies evaluating AI algorithms against a reference standard (clinical examination, expert consensus, or surgical findings) for furcation defect detection/classification on dental radiographs. Risk of bias was assessed using QUADAS-2. Because of study heterogeneity, a meta-analysis was not performed.

Results: Eight retrospective studies were included, utilizing various AI algorithms (e.g., ResNet, UNet, YOLO-v4, Vision Transformers) and radiographic modalities (periapical, panoramic, CBCT). Studies employing advanced deep learning models on 2D radiographs generally reported high diagnostic accuracy for detecting furcation involvement, with several reporting high sensitivity, specificity, and AUC values. However, performance varied by AI model and imaging modality. Proprietary AI tools showed suboptimal results in some studies. Classification of furcation severity was less consistently reported.

Conclusion: AI algorithms, particularly advanced deep learning models applied to well-annotated 2D radiographs, show promise for accurate furcation defect detection. Nonetheless, the field exhibits methodological and reporting heterogeneity. Future research should prioritize standardized protocols, direct comparisons with clinicians, and development of clinically translatable AI tools to improve early and accurate diagnosis of furcation involvement.

Purpose: Haller cells (HCs) represent an anatomical variation in the maxillofacial region, frequently linked to sino-nasal pathologies. Numerous regional studies have reported the prevalence of HCs using various imaging modalities. This systematic review aims to evaluate the prevalence of HCs as reported in the existing literature.

Materials and methods: A comprehensive literature search was carried out across multiple databases, including ScienceDirect, PubMed, Scopus, Dentistry and Oral Sciences (EBSCO), Ovid, and LILACS. Different keyword combinations employing Boolean logic were used to identify relevant studies. Data extraction procedures adhered closely to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The quality of studies was assessed using the Critical Appraisal Skills Program (CASP) checklist for cross-sectional studies.

Results: After data extraction, 9 studies qualified for critical analysis. The highest reported prevalence of HCs was 66.84%, whereas the lowest was 16%. Across these 9 studies, the average prevalence was 32.40%. Unilateral HCs predominated in most reported studies. Four studies provided details regarding the shapes of HCs, while size information was available in three studies. Eight of the 9 included studies demonstrated strong evidence quality according to the CASP checklist.

Conclusion: Approximately one-third of radiographic scans analyzed in published studies revealed the presence of HCs. Unilateral HCs were found to be more common than bilateral HCs. The most frequently reported shapes were round, ovoid, and teardrop, with the majority measuring between 2 and 4 mm.

Purpose: This study aimed to establish an expert consensus on a set of principles for radiation protection in oral and maxillofacial radiology in Korea. Although national and international guidelines exist, their practical application to dental radiology remains limited, with key clinical components not subject to mandatory enforcement. Therefore, guidelines tailored specifically to dental radiology are necessary to ensure consistent and effective radiation safety.

Materials and methods: A modified Delphi method was utilized, involving 20 experts-7 specialists in oral and maxillofacial radiology and 13 in medical radiology. A Guideline Development Committee initially drafted the principles, which were refined over 3 rounds of email-based surveys. Panelists evaluated each principle using a 9-point Likert scale, with quantitative scores and qualitative feedback informing the revision process.

Results: Consensus was reached on 10 principles, addressing radiographic justification, imaging scope limitations, pregnancy considerations, pediatric optimization, portable radiography, radiation dose monitoring and equipment operation. Final agreement scores approached 9.0, with standard deviations ≤0.7, confirming strong expert consensus.

Conclusion: The finalized principles constitute a structured, evidence-based guideline aligned with international standards while addressing specific challenges unique to oral and maxillofacial radiology. They offer practical strategies to enhance patient safety and standardize radiographic decision-making. Further research should investigate their clinical implementation and recommend periodic updates to reflect evolving technologies.

Purpose: This study aimed to evaluate artefact expression and volumetric distortion of endodontic obturation materials with varying radiopacity in root canal-treated teeth using cone-beam computed tomography (CBCT).

Material and methods: The radiopacity test was performed according to ANSI/ADA standards for AH Plus sealer, Bio-C Sealer, and conventional and bioceramic cones. Upper incisors were selected and instrumented with WaveOne Gold files (45/05). Teeth were individually positioned into empty sockets of a human jaw, and CBCT scans were initially performed (control group). Each tooth was subsequently filled with different combinations of root filling materials. Mean dentin gray values, image noise, and filling material volumes were measured and segmented. Data comparisons among groups were conducted using analysis of variance and the paired t-test (α=0.05).

Results: The conventional cone and AH Plus demonstrated the highest radiopacity. CBCT images exhibited significantly higher mean gray values, noise, and volumetric distortion for groups with conventional cones and AH Plus sealer (P<0.05).

Conclusion: Bioceramic materials, which had lower radiopacity, generated fewer artefacts and less volumetric distortion compared to conventional gutta-percha cones and AH Plus sealer.

Purpose: This study assessed the effectiveness of an educational video in reducing tongue positioning errors on panoramic radiographs.

Materials and methods: An educational video instructing patients on proper tongue positioning during panoramic radiograph acquisition was sent via WhatsApp (WhatsApp Inc., Menlo Park, CA, USA) at the time of appointment scheduling. Patients were instructed to view the video again before their appointment. Collected data included patients' sex, age, scheduling method, educational background, the necessity for panoramic radiograph retake, and the reason for retake. The frequency of retakes due to tongue positioning errors was compared with retrospective data from patients who did not receive the video, resulting in the evaluation of 1,088 panoramic radiographs. Descriptive data analyses were conducted, and simple and multiple logistic regression models were applied with a significance level of 5%.

Results: Of the 1,088 panoramic radiographs evaluated, 69 displayed tongue positioning errors. Of these, 53 radiographs were from patients without access to the educational video, whereas only 16 were from patients who had received the video (P<0.05). Patients without video access were 2.07 times more likely to exhibit tongue positioning errors than those who had access. The other variables assessed (sex, age, scheduling method, and educational background) did not significantly influence tongue positioning errors (P>0.05).

Conclusion: Providing patients with an educational video on proper tongue positioning significantly reduced tongue positioning errors on panoramic radiographs.

Purpose: Classifying cervical vertebral maturation (CVM) stages aids in determining the peak period of growth and in predicting growth rates and patterns. This study aimed to develop a multistage framework for the automated classification of CVM.

Materials and methods: The dataset consisted of 2325 lateral cephalograms. Two orthodontists independently classified these images into 6 categories. One object detection model (Faster RCNN) and 2 classification models (ResNet 101) were implemented using the Python programming language and the PyTorch library. The first classification model divided images into 2 primary groups (CS1-CS3 and CS4-CS6) based on the morphology of the C4 vertebra. The second model subsequently classified each primary group into their respective subcategories. Each classification model was trained and evaluated using a 10-fold cross-validation strategy. The learning process of the models was visualized with gradient-weighted class activation maps.

Results: The overall framework achieved an accuracy of 82.96%. Object detection for region-of-interest extraction reached mAP50 and mAP75 values of 100%. The first classification model demonstrated an accuracy of 99.10% on the hold-out test set. The classifier for CS1-CS3 images showed higher accuracy than the classifier for CS4-CS6 images (86.49% vs. 82.80%).

Conclusion: The accuracy achieved by this fully automated framework was promising.

Purpose: This study analyzed cone-beam computed tomography images of 27 patients with multiple myeloma at different disease stages to identify jawbone destruction patterns and assess their associations with clinical data.

Materials and methods: In this cross-sectional study, 2 trained examiners performed standardized, consensus-based image analyses. Lesions were classified into 4 distinct bone destruction patterns: diffuse, multilocular, unilocular, and punched-out. Clinical data were collected from medical records.

Results: The sample included 51.8% male and 48.2% female patients, predominantly between 42 and 60 years old. All cases exhibited diffuse bone destruction affecting both jaws. Multilocular and unilocular patterns were observed in 51.9% and 29.6% of cases, respectively, while no punched-out lesions were identified. The unilocular pattern was significantly associated with cases classified as International Staging System stage I and Durie-Salmon stage IIIA.

Conclusion: Among the studied cases of multiple myeloma, the most frequently observed bone destruction patterns were diffuse and multilocular. The absence of punched-out lesions may be attributable to the use of 3-dimensional imaging. A clear association was identified between the unilocular pattern and disease staging.

Purpose: This study aimed to evaluate the influence of different cone-beam computed tomography (CBCT) image reconstruction parameters (slice thickness, noise filter application and orthogonal plane) on the calculation of bone fractal dimension and, based on those findings, to determine the optimal protocol for this type of assessment.

Materials and methods: The sample consisted of 18 patients who underwent CBCT scans of the mandible and bone densitometry examinations. Four mandibular regions of interest were selected from the scans, with various image reconstruction parameters applied. Fractal dimension was calculated using the box-counting method. Two independent observers performed the evaluations, and all analyses were conducted with a significance level of 5%.

Results: The retromolar triangle and mandibular body regions did not demonstrate statistically significant differences when different tomographic reconstruction parameters were applied (P>0.05). The mandibular base did not display a consistent pattern that could define the influence of these parameters on its evaluation. The symphysis region showed improved performance in fractal analysis when using sagittal plane images with a 1 mm slice thickness.

Conclusion: Operator-dependent parameters inherent to navigation software can influence fractal dimension analysis, with variations depending on the region of interest. The most appropriate parameters for this evaluation were identified as the sagittal plane with a 1 mm slice thickness. Among the regions assessed, the mandibular body was found to be the most suitable for fractal dimension analysis in CBCT.