Comparison of linear and angular measurements in CBCT scans using 2D and 3D rendering software

Accuracy of conventional versus cone-beam CT-synthesised lateral cephalograms for cephalometric analysis: A systematic review

OBJECTIVE

To assess the accuracy of cone-beam computed tomography (CBCT)-synthesised lateral cephalograms (CSLCs) compared with conventional lateral cephalograms for cephalometric analysis in human participants and skull models.

METHODS

The authors performed a search of PubMed, Scopus, Google Scholar and Embase databases on 4 October 2021. Included studies met the following criteria: published in English; compared conventional lateral cephalograms and CSLCs; assessed hard- and soft-tissue landmarks; and were performed on human or skull models. Data extraction from eligible studies was performed by two independent reviewers. The quality of evidence was assessed using the Joanna Briggs Institute (JBI) Critical Appraisal Checklist tool - diagnostic accuracy studies.

RESULTS

A total of 20 eligible articles were included in this systematic review. Of these 20 studies, 17 presented with a low risk of bias, while three were found to have a moderate risk of bias. Hard- and soft-tissue analyses were evaluated for each imaging modality. The findings reveal that CSLCs are accurate and comparable to conventional lateral cephalograms for cephalometric analysis and demonstrate good inter-observer reliability. Four studies reported a higher accuracy with CSLCs.

CONCLUSION

Overall, the diagnostic accuracy and reproducibility of CSLCs were comparable to conventional lateral cephalograms in cephalometric analysis. It is justified that patients who have an existing CBCT scan do not need an additional lateral cephalogram, minimising unnecessary radiation exposure, expenses and time for the patient. Larger voxel sizes and low-dose CBCT protocols can be considered to minimise radiation exposure.

REGISTRATION

This study was registered with PROSPERO (CRD42021282019).

Assessing the reliability of CBCT-based AI-generated STL files in diagnosing osseous changes of the mandibular condyle: a comparative study with ground truth diagnosis

OBJECTIVES

This study aims to evaluate the reliability of AI-generated STL files in diagnosing osseous changes of the mandibular condyle and compare them to a ground truth (GT) diagnosis made by six radiologists.

METHODS

A total of 432 retrospective CBCT images from four universities were evaluated by six dentomaxillofacial radiologists who identified osseous changes such as flattening, erosion, osteophyte formation, bifid condyle formation, and osteosclerosis. All images were evaluated by each radiologist blindly and recorded on a spreadsheet. All evaluations were compared and for the disagreements, a consensus meeting was held online to create a uniform GT diagnosis spreadsheet. A web-based dental AI software was used to generate STL files of the CBCT images, which were then evaluated by two dentomaxillofacial radiologists. The new observer, GT, was compared to this new STL file evaluation, and the interclass correlation (ICC) value was calculated for each pathology.

RESULTS

Out of the 864 condyles assessed, the ground truth diagnosis identified 372 cases of flattening, 185 cases of erosion, 70 cases of osteophyte formation, 117 cases of osteosclerosis, and 15 cases of bifid condyle formation. The ICC values for flattening, erosion, osteophyte formation, osteosclerosis, and bifid condyle formation were 1.000, 0.782, 1.000, 0.000, and 1.000, respectively, when comparing diagnoses made using STL files with the ground truth.

CONCLUSIONS

AI-generated STL files are reliable in diagnosing bifid condyle formation, osteophyte formation, and flattening of the condyle. However, the diagnosis of osteosclerosis using AI-generated STL files is not reliable, and the accuracy of diagnosis is affected by the erosion grade.

Cone beam computed tomography evaluation of the relationship between atlantodental interval and skeletal facial morphology in adolescents

Introduction

In the pediatric population, computed tomography examination of the upper cervical spine plays an important role in the diagnosis of neurological injuries involving that region. Due to the interconnected nature of the craniofacial structures, a structural change in one is expected to also cause changes in the other structures.

Objective

The aim of this study was to evaluate relationships between atlantodental interval, cervical vertebral morphology, and facial structure in healthy adolescents using cone beam computed tomography.

Methods

Thirty subjects aged 14–20 years (10 males, mean age: 17.2 years; 20 females, mean age: 17.9 years) were included in the study. The anterior, lateral and posterior atlantodental intervals, and vertical and anteroposterior dimensions of the first and second cervical vertebrae were evaluated from cone beam computed tomography images. Facial morphology was evaluated using 7 parameters on lateral cephalometric cone beam computed tomography images and 6 parameters on posteroanterior images. The Mann–Whitney U test and Wilcoxon test were used for statistical analyses.

Results

Comparisons between males and females showed that most parameters were larger in males, with significant differences in vertical facial dimensions (anterior lower face height: p = 0.05; anterior upper face height: p = 0.001), (distance between the most internal point of the frontozygomatic suture and midsagittal reference plane; p = 0.01), (the distance between the deepest point of the right alveolar maxillar process and midsagittal reference plane; p = 0.001), and C2 vertebral dimensions. The anterior and lateral atlantodental interval values correlated with maxilla position relative to the mandible angle, and the anterior atlantodental interval correlated with lower anterior facial height (p = 0.05). Dimensional measurements of the C1 and C2 vertebrae were correlated with both anterior facial heights and some posteroanterior parameters.

Conclusion

Sagittal, vertical, and transverse facial dimensions and positions were strongly associated with C1 and C2 vertebral dimensions, and the maxillomandibular relationship may affect atlantodental interval. Therefore, including craniofacial features in assessment of the atlantodental area and vertebral distances in adolescents may be beneficial.

A comparative study of digital lateral radiography and virtual cone-beam computed assisted cephalogram in cephalometric measurements

Objectives: To assess discrepancies in cephalometric measurements from digital lateral radiography and virtual cone-beam computed assisted tomography cephalogram. Materials and methods: Forty digital lateral radiographs and forty virtual cephalograms obtained by cone-beam computed assisted tomography were analyzed, corresponding to forty patients from the nstituto de Diagnóstico Maxilofacial in Lima, Peru. The principal investigator, who had been previously calibrated, made two measurements within a timespan of fifteen days using the analysis of Steiner and the NemoCeph software, and the difference between the obtained measurements was evaluated to determine if it was significant. Results: For digital lateral radiographs the difference varied between 0.00º - 0.45º and 0.01mm - 0.16mm, with statistical significance for distance between Pg and NB for lateral virtual cephalograms between 0.03º - 0.73º and 0.01mm - 0.43mm, with statistical significance for SE distance. The comparison between the two types of image in the first measurement showed a difference of 0.08º - 1.15º and 0.00mm - 1.43mm with statistical significance for four angular measurements and one linear. The comparison between the two types of image in the second measurement showed a difference of 0.13º - 1º and 0.02mm - 1.32mm with a statistically significant difference for three angular and two linear measurements. Conclusions: The difference between the two types of image is minimal; Both evaluated methods can be used effectively.

Evaluation of calcium (Ca2+) and hydroxide (OH-) ion diffusion rates of indirect pulp capping materials

INTRODUCTION

The aim of this study was to evaluate and compare the calcium (Ca2+) and hydroxide (OH-) ion release of 4 artificially produced pulp capping materials (MTA, Biodentin, TheraCal LC, Calsimol) used for indirect pulp capping treatment.

METHODS

In total, 70 freshly extracted human third molar teeth were used for the study. Cavities of extracted teeth were prepared by round burs. The remaining dentin thickness (1 ± 0.3 mm) tissue was measured by a micrometer and cone beam computerized tomography. Indirect pulp capping was performed in the cavities using Calcimol, MTA, TheraCal LC and Biodentin. The leached Ca2+ were measured using optical emission spectrometry and the release of OH- ions using a pH meter. The measurements were performed after 24 hours, 7 days and 28 days in saline solution. Statistical analysis was performed using 1-way and 2-way analysis of variance (ANOVA) tests (p<0.05).

RESULTS

Ca2+ ions were detected in treated saline solution during the experimental period for all materials. All the measurements of Biodentin and Theracal LC levels for Ca2+ ions were higher than those of the other materials (p<0.05). For all materials, Ca2+-ion release increased during the first 7 days followed by a linear decrease during the subsequent study periods. The Biodentine group showed the highest OH- ion rates compared to the other materials in the 24-hour examination period, while the scores gradually decreased during the subsequent measurement periods (p<0.05).

CONCLUSIONS

Tricalcium silicate materials such as Biodentine and TheraCal LC used in this study may be preferable for indirect pulp capping because of their stimulation of hard tissue formation and ion-releasing ability.

Comparison of hand and semiautomatic tracing methods for creating maxillofacial artificial organs using sequences of computed tomography (CT) and cone beam computed tomography (CBCT) images

INTRODUCTION

The aim of this study was to compare the paranasal sinus volumes obtained by manual and semiautomatic imaging software programs using both CT and CBCT imaging.

METHODS

121 computed tomography (CT) and 119 cone beam computed tomography (CBCT) examinations were selected from the databases of the authors' institutes. The Digital Imaging and Communications in Medicine (DICOM) images were imported into 3-dimensonal imaging software, in which hand mode and semiautomatic tracing methods were used to measure the volumes of both maxillary sinuses and the sphenoid sinus. The determined volumetric means were compared to previously published averages.

RESULTS

Isometric CBCT-based volume determination results were closer to the real volume conditions, whereas the non-isometric CT-based volume measurements defined coherently lower volumes. By comparing the 2 volume measurement modes, the values gained from hand mode were closer to the literature data. Furthermore, CBCT-based image measurement results corresponded to the known averages.

CONCLUSIONS

Our results suggest that CBCT images provide reliable volumetric information that can be depended on for artificial organ construction, and which may aid the guidance of the operator prior to or during the intervention.