Cone beam computed tomography: basics and applications in dentistry

The Evolution of Custom Subperiosteal Implants for Treatment of Partial or Complete Edentulism in Patients with Severe Alveolar Ridge Atrophy

Dental implants have always played an important role in dentistry and have been used to replace missing teeth since around 600 AD. They can be classified into three groups: endosteal, subperiosteal, and transosteal. Over time, different materials have been used to manufacture dental implants and these, in turn, can be divided into three groups: metals, ceramics, and polymers. Today, the most commonly used treatment for edentulism is the use of endosteal implants. However, such an approach cannot be used in patients with severe alveolar ridge atrophy and, in such cases, custom subperiosteal implants are an alternative. This review article focuses on historical developments and improvements that have been made over recent years in treatment options for patients suffering from edentulism and significant resorption of the alveolar ridge. These treatment options involve the utilization of custom subperiosteal implants. This paper looks at the historical evolution of these implants, the significance of diagnostic imaging, and the application of the contemporary methods of production, such as CAD-CAM and additive manufacturing. The research emphasizes the importance of accuracy and personalization provided by these emerging technologies that have rendered subperiosteal implants a more feasible and less intrusive alternative for patients suffering from significant bone loss.

Evaluation of the (clinical) relevance of gross anatomical teaching for dental students and practicing oral surgeons in Berlin

Knowledge of human anatomy is an important scientific basis for every dentist, and the adequacy of its provision by anatomy faculties is therefore constantly being adapted. Students' motivation to comprehend knowledge is a fundamental prerequisite and has been shown to increase when the relevance of the subject is clear. This study examines dental students' perceptions of the relevance of the anatomy curriculum, with particular reference to clinical practice and the dissection course, in conjunction with the perceptions of surgically specialized dentists. The distinctions between the participating groups concerning their perceived relevance are being discussed particularly regarding their applicability to improve the anatomical education of dental students. The overall aim is to find and highlight aspects of the clinical use of anatomical knowledge towards students, which they are unable to apprehend yet. A questionnaire consisting of information on demographics and professional competence as well as a Likert-style section was administered to dental students at Charité Universitätsmedizin in 2019/2020 (n = 322, 84.96%) and a modified version with congruent questions was administered retrospectively to oral surgeons practicing in Berlin in 2020 (n = 81, 63.3%). A Wilcoxon rank-sum test was used to examine differences in responses between the cohorts. Demographic data and professional competence were correlated with the participants' ratings of the given statements using Spearman's rank correlation coefficient. Both groups of respondents expressed a high level of appreciation of the overall relevance of anatomical knowledge, valued the teaching of all human anatomy for dental education, and recognized the relevance of anatomical knowledge for clinical practice. The importance of the dissection course was also rated relatively high by both groups of respondents. The overall appreciation of anatomical knowledge was more prevalent among oral surgeons. There were few correlations between demographics in our findings, showing slightly higher motivation in female students and a growing appreciation of anatomical knowledge as students qualification progressed. The demographics and post-qualification experience of the participating oral surgeons did not influence their perceptions. The results of this survey suggest that there is potential to increase the motivation of dental students to learn anatomy by emphasizing clinical relevance, as perceived by experienced practitioners, during the anatomy curriculum.

Novel AI-based tool for primary tooth segmentation on CBCT using convolutional neural networks: A validation study

BACKGROUND

Primary teeth segmentation on cone beam computed tomography (CBCT) scans is essential for paediatric treatment planning. Conventional methods, however, are time-consuming and necessitate advanced expertise.

AIM

The aim of this study was to validate an artificial intelligence (AI) cloud-based platform for automated segmentation (AS) of primary teeth on CBCT. Its accuracy, time efficiency, and consistency were compared with manual segmentation (MS).

DESIGN

A dataset comprising 402 primary teeth (37 CBCT scans) was retrospectively retrieved from two CBCT devices. Primary teeth were manually segmented using a cloud-based platform representing the ground truth, whereas AS was performed on the same platform. To assess the AI tool's performance, voxel- and surface-based metrics were employed to compare MS and AS methods. Additionally, segmentation time was recorded for each method, and intra-class correlation coefficient (ICC) assessed consistency between them.

RESULTS

AS revealed high performance in segmenting primary teeth with high accuracy (98 ± 1%) and dice similarity coefficient (DSC; 95 ± 2%). Moreover, it was 35 times faster than the manual approach with an average time of 24 s. Both MS and AS demonstrated excellent consistency (ICC = 0.99 and 1, respectively).

CONCLUSION

The platform demonstrated expert-level accuracy, and time-efficient and consistent segmentation of primary teeth on CBCT scans, serving treatment planning in children.

Image fusion-based low-dose CBCT enhancement method for visualizing miniscrew insertion in the infrazygomatic crest

Digital dental technology covers oral cone-beam computed tomography (CBCT) image processing and low-dose CBCT dental applications. A low-dose CBCT image enhancement method based on image fusion is proposed to address the need for subzygomatic small screw insertion. Specifically, firstly, a sharpening correction module is proposed, where the CBCT image is sharpened to compensate for the loss of details in the underexposed/over-exposed region. Secondly, a visibility restoration module based on type II fuzzy sets is designed, and a contrast enhancement module using curve transformation is designed. In addition to this, we propose a perceptual fusion module that fuses visibility and contrast of oral CBCT images. As a result, the problems of overexposure/underexposure, low visibility, and low contrast that occur in oral CBCT images can be effectively addressed with consistent interpretability. The proposed algorithm was analyzed in comparison experiments with a variety of algorithms, as well as ablation experiments. After analysis, compared with advanced enhancement algorithms, this algorithm achieved excellent results in low-dose CBCT enhancement and effective observation of subzygomatic small screw implantation. Compared with the best performing method, the evaluation metric is 0.07-2 higher on both datasets. The project can be found at: https://github.com/sunpeipei2024/low-dose-CBCT .

Evaluation of a 3D-Printed Cleft Palate Obturator Using a Low-Dose Cone Beam Computed Tomography Acquisition Protocol: A Proof-of-Concept Study

Cone beam computed tomography (CBCT) technology is increasingly utilized in the head and neck region and is valuable in treatment planning for cleft palate patients, potentially enabling the creation of 3D-printed obturators to assist with feeding and speech. This technical report investigates the feasibility of using data from a 360-degree CBCT scan to accurately produce a cleft palate obturator and assesses whether a lower-dose 180-degree CBCT scan can achieve a comparable result. A simulated cleft palate was crafted on a dehydrated human skull, which was then scanned using both 360-degree and 180-degree CBCT scanning protocols. Two obturators were digitally designed based on the segmented images from each scan and subsequently 3D printed. Evaluation of the segmented images and 3D-printed obturators from both protocols demonstrated clear visualization of anatomical landmarks and identical scores across all parameters, suggesting that the 180-degree CBCT scan can produce an obturator of comparable quality to that of the 360-degree scan, with the added benefit of reduced radiation exposure.

Root Canal Instrumentation: Current Trends and Future Perspectives

The evolution of root canal instrumentation techniques has significantly impacted the field of endodontics, enhancing both the efficiency and outcomes of treatments. This review outlines the transition from manual to mechanical and rotary instruments, highlighting the role of nickel-titanium (NiTi) alloys and smart technologies in advancing procedural precision and reducing patient discomfort. Key historical developments and technological innovations, such as digital imaging and navigation systems, are explored for their contributions to improved clinical outcomes and patient satisfaction. Additionally, the review addresses the challenges presented by the complex anatomy of the root canal system and the advent of current instrumentation techniques. The potential of emerging trends, including artificial intelligence and advances in materials science, is discussed in the context of future endodontic practices. Despite the progress, challenges related to using advanced instrumentation methods, ethical considerations, and the cost factor of new technologies persist. The present review underscores the ongoing need for research and development to further refine root canal instrumentation techniques, ensuring that advancements in endodontic care remain patient-centered and accessible.

Performance of cone-beam computed tomography (CBCT) in comparison to conventional computed tomography (CT) and magnetic resonance imaging (MRI) for the detection of bone invasion in oral squamous cell cancer (OSCC): a prospective study

BACKGROUND

Oral squamous carcinoma (OSCC) is often diagnosed at late stages and bone erosion or invasion of the jawbone is frequently present. Computed tomography (CT) and magnetic resonance imaging (MRI) are known to have high diagnostic sensitivities, specificities, and accuracies in detecting these bone affections in patients suffering from OSCC. To date, the existing data regarding the impact of cone-beam computed tomography (CBCT) have been weak. Therefore, this study aimed to investigate whether CBCT is a suitable tool to detect bone erosion or invasion in patients with OSCC.

METHODS

We investigated in a prospective trial the impact of CBCT in the diagnosis of bone erosion or invasion in patients with OSCC who underwent surgery. Every participant received a CBCT, CT, and MRI scan during staging. Imaging modalities were evaluated by two specialists in oral and maxillofacial surgery (CBCT) and two specialists in radiology (CT and MRI) in a blinded way, to determine whether a bone affection was present or not. Reporting used the following 3-point system: no bony destruction ("0"), cortical bone erosion ("1"), or medullary bone invasion ("2"). Histological examination or a follow-up served to calculate the sensitivities, specificities, and accuracies of the imaging modalities.

RESULTS

Our results revealed high diagnostic sensitivities (95.6%, 84.4%, and 88.9%), specificities (87.0%, 91.7%, and 91.7%), and accuracies (89.5%, 89.5%, and 90.8%) for CBCT, CT, and MRI. A pairwise comparison found no statistical difference between CBCT, CT, and MRI.

CONCLUSION

Our data support the routine use of CBCT in the diagnosis of bone erosion and invasion in patients with OSCC as diagnostic accuracy is equal to CT and MRI, the procedure is cost-effective, and it can be performed during initial contact with the patient.

Do Cone Beam CT Picture Archiving and Communication Systems Viewer Interfaces Meet the Expectations of Dental Professionals From a Usability Perspective?

Background Cone beam computed tomography (CBCT) has revolutionized dental and maxillofacial imaging by providing high-resolution 3D visualizations, essential for accurate diagnosis and treatment planning. Despite its clinical advancements, the usability of CBCT viewer interfaces, which play a crucial role in the effective interpretation of imaging data, remains a critical concern. Objective This study aims to evaluate the usability of a CBCT viewer interface in clinical settings, focusing on the effectiveness, efficiency, and satisfaction perspectives, to identify potential areas for improvement. Methods Twenty-two participants (N=22) were assigned the task of locating the mental foramen in a mandible dataset, selected randomly, using the multiplanar reconstruction (MPR) mode of a CBCT viewer interface on a local network. The task's effectiveness was gauged by the completion rate, while efficiency was measured through the duration of the task, the number of mouse clicks, and the cursor's path in both pixels and meters. Satisfaction or perceived usability was evaluated using the system usability scale (SUS-TR), and computer system usability questionnaire (T-CSUQ), among other scales, with participants also providing open-ended feedback. Demographic characteristics served as classification variables. Results All participants completed the given task. No demography-related differences in efficiency were observed. Perceived usability (SUS-TR: 60.68±19.58, T-CSUQ: 43.63±16.34) was below the industry standards, categorizing the system as a detractor. Commonly reported issues included accessing the MPR window, cursor behavior, and unclear error messages. The mean SUS-TR score negatively correlated with efficiency-related variables (p<0.05 for each). Conclusions The study's findings indicate that the CBCT viewer interface does not fully meet dental professionals' usability expectations, as evidenced by the task's completion rate, efficiency metrics, and below-average usability scores. Despite the successful task completion by all participants, the identified issues in interface design, such as difficulties in accessing the MPR window and unclear error messages, highlight significant areas for improvement. To enhance user satisfaction and efficiency, future developments of CBCT viewer interfaces should incorporate feedback from end-users and prioritize user-friendly design principles.

The success rate of mini-screws for incisors intrusion and patient age, gender, and insertion angle in the maxilla using CBCT and implant-guided surgery. A split-mouth, randomized control trail

BACKGROUND AND OBJECTIVES

The intrusion of anterior teeth is a routine procedure in orthodontics, which has been performed efficiently with the help of mini-screws in the anterior region, especially the upper maxilla. This study aimed to investigate the effect of insertion angle and sociodemographic features on the success rate of mini-screws at the anterior maxillary region.

MATERIALS AND METHODS

Twenty-nine patients (18 Females and 11 Males) aged 18-40 years old were involved in the current study. A split-mouth design was carried out in which recruited patients needed bilateral anterior screws at the labial bone in the region of the incisor for the intrusion of upper anterior incisor teeth as part of their orthodontic treatment with a fixed appliance (upper right side received 90-degree insertion angle mini-screw and 45° for left side) using a surgical guide fabricated from patients CBCT and intraoral scans. The mini-screws were inserted at the attached gingiva bilaterally to achieve intrusion of upper anterior teeth with a power chain ligated from the main archwire to the anterior min-implants. The patient was recalled monthly for orthodontic appliance activation and screw assessment for 6 months. The intrusion force was 15 g on each side.

RESULTS

The results of the study showed that screw stability was higher in the male group than the female group at the 6th monthly follow-up visit with a statistically significant difference between both genders (P = .044). Concerning insertion angle, results showed a statistically significant difference between 45° and 90° as an insertion angle with a P-value <.01 in most of the follow-up months.

CONCLUSION

This study found that male patients with mini-screws inserted at 90° showed greater screw stability over time.

Evaluation of the Success of Autogenous Block Grafting in Atrophic Maxillary and Mandibular Ridges Prior to and After Implant Placement

BACKGROUND

Dental implantology's success relies on adequate bone volume and quality, necessitating bone augmentation for implant placement. Primary lateral bone augmentation, utilizing autogenous block grafts, addresses horizontal bone loss.

OBJECTIVE

This study aims to evaluate the efficacy of autogenous block grafting, specifically ramus and fibula blocks, in addressing severe atrophic ridges before and after implant placement.

METHODS

Twenty-one patients underwent block grafting, predominantly using the ramus technique (80/20 ratio). CBCT measurements assessed horizontal grafting outcomes. Implant success and bone volume changes were analyzed.

RESULTS

Post-grafting, bone width increased from 1.8-3.1 mm to 4.5-6 mm, exceeding critical thresholds. Implant success reached 95%, indicating the grafting techniques' effectiveness.

CONCLUSION

Autogenous block grafting, especially with ramus and fibula blocks, transforms severe atrophic ridges, enabling successful implant integration. Long-term follow-up is essential for a comprehensive evaluation.

CLINICAL RELEVANCE

This study provides crucial insights into autogenous block grafting's transformative impact on challenging cases, guiding future applications in reconstructive dentistry.

A Review on Cone-Beam Computed Tomography and its Application in Dentistry

Cone-beam computed tomography (CBCT), which has benefits over traditional radiography in this age of cutting-edge technology, has become increasingly popular in oral radiology. The utilization of CBCT is experiencing significant growth in several dental specialties, mainly for diagnostic purposes and treatment planning. Image acquisition and 3D imaging have helped the clinical use of cone-beam technology. The equipment has a user-friendly interface, minimum image distortion, and images compatible with many planning and simulation software applications. The present literature review aims to discuss CBCT and its various applications in dentistry.

Impact of 3D imaging techniques and virtual patients on the accuracy of planning and surgical placement of dental implants: A systematic review

Aim

The integration of advanced technologies, including three-dimensional (3D) imaging modalities and virtual simulations, has significantly influenced contemporary approaches to preoperative planning in implant dentistry. Through a meticulous analysis of relevant studies, this review synthesizes findings related to accuracy outcomes in implant placement facilitated by 3D imaging in virtual patients.

Methods

A comprehensive literature search was conducted across relevant databases to identify relevant studies published to date. The inclusion criteria were studies utilizing 3D imaging techniques, virtual patients, and those focusing on the accuracy of dental implant planning and surgical placement. The selected studies were critically appraised for their methodological quality.

Results

After a rigorous analysis, 21 relevant articles were included out of 3021 articles. This study demonstrates the versatility and applicability of these technologies in both in vitro and in vivo settings. Integrating Computer-Aided Design/Computer-Aided Manufacturing (CAD/CAM), cone bean computed tomography (CBCT), and advanced 3D reconstruction methodologies showcases a trend toward enhanced precision in implant planning and placement. Notably, the evaluation parameters varied, encompassing distances, discrepancies, and deviations in the implant placement. The ongoing integration of systems such as dynamic navigation systems, augmented reality, and sophisticated software platforms shows a promising trajectory for the continued refinement of virtual reality applications in dental implantology, providing valuable insights for future research and clinical implementation. Moreover, using stereolithographic surgical guides, virtual planning with CBCT data, and 3D-printed templates consistently demonstrates enhanced precision in dental implant placement compared to traditional methods.

Conclusion

The synthesis of the available evidence underscores the substantial positive impact of 3D imaging techniques and virtual patients on dental implant planning and surgical placement accuracy. Utilizing these technologies contributes to a more personalized and precise approach that enhances overall treatment outcomes. Future research directions and potential refinements to the application of these technologies in clinical practice should be discussed.

Diagnostic performance of cone-beam computed tomography for apical periodontitis: a systematic review and meta-analysis

Purpose

We aimed to conduct a systematic review and meta-analysis of studies examining the performance of cone-beam computed tomography (CBCT) imaging in apical periodontitis (AP) prediction. This was done to address the contradictory results reported in the existing literature on this topic.

Material and methods

We searched the Embase, PubMed, Cochrane library, and Scopus databases for literature published from inception to 30 June 2023 without language restriction using appropriate keywords. We included studies that reported the diagnostic accuracy values of CBCT in AP detection among humans by comparing AP diagnosis with a control group without lesions. We pooled the diagnostic accuracy values using a random effects model and presented the estimates as percentage and 95% confidence interval (CI). The heterogeneity between the surveys was explored by I2 statistic.

Results

Out of 301 citations initially identified, a total of 8 eligible studies were finally included. According to the analyses, the overall pooled sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) estimated for CBCT were 94.6% (95% CI: 90.2-97.1; I2 = 55.9%, p = 0.026), 91.2% (95% CI: 81.7-96.0; I2 = 81.6%, p < 0.001), 93.0% (95% CI: 87.4-96.2; I2 = 56.5%, p = 0.024), and 92.3% (95% CI: 82.3-96.8; I2 = 86.4%, p < 0.001), respectively. The overall pooled sensitivity, specificity, PPV, and NPV of digital radiography were 61.0% (95% CI: 38.3-79.8; I2 = 94.4%, p < 0.001), 97.3% (95% CI: 85.6-99.5; I2 = 86.7%, p < 0.001), 98.3% (95% CI: 92.0-99.6; I2 = 74.4%, p = 0.002), and 41.6% (95% CI: 28.0-56.6; I2 = 89.5%, p < 0.001), respectively.

Conclusions

CBCT imaging has excellent diagnostic accuracy in AP prediction. Also, CBCT has better discriminant test performance for AP than digital radiography.

Deep learning for classifying the stages of periodontitis on dental images: a systematic review and meta-analysis

BACKGROUND

The development of deep learning (DL) algorithms for use in dentistry is an emerging trend. Periodontitis is one of the most prevalent oral diseases, which has a notable impact on the life quality of patients. Therefore, it is crucial to classify periodontitis accurately and efficiently. This systematic review aimed to identify the application of DL for the classification of periodontitis and assess the accuracy of this approach.

METHODS

A literature search up to November 2023 was implemented through EMBASE, PubMed, Web of Science, Scopus, and Google Scholar databases. Inclusion and exclusion criteria were used to screen eligible studies, and the quality of the studies was evaluated by the Grading of Recommendations Assessment, Development and Evaluation (GRADE) methodology with the QUADAS-2 (Quality Assessment of Diagnostic Accuracy Studies) tool. Random-effects inverse-variance model was used to perform the meta-analysis of a diagnostic test, with which pooled sensitivity, specificity, positive likelihood ratio (LR), negative LR, and diagnostic odds ratio (DOR) were calculated, and a summary receiver operating characteristic (SROC) plot was constructed.

RESULTS

Thirteen studies were included in the meta-analysis. After excluding an outlier, the pooled sensitivity, specificity, positive LR, negative LR and DOR were 0.88 (95%CI 0.82-0.92), 0.82 (95%CI 0.72-0.89), 4.9 (95%CI 3.2-7.5), 0.15 (95%CI 0.10-0.22) and 33 (95%CI 19-59), respectively. The area under the SROC was 0.92 (95%CI 0.89-0.94).

CONCLUSIONS

The accuracy of DL-based classification of periodontitis is high, and this approach could be employed in the future to reduce the workload of dental professionals and enhance the consistency of classification.

Reliability and accuracy of a semi-automatic segmentation protocol of the nasal cavity using cone beam computed tomography in patients with sleep apnea

OBJECTIVES

The objectives of this study included using the cone beam computed tomography (CBCT) technology to assess: (1) intra- and inter-observer reliability of the volume measurement of the nasal cavity; (2) the accuracy of the segmentation protocol for evaluation of the nasal cavity.

MATERIALS AND METHODS

This study used test-retest reliability and accuracy methods within two different population sample groups, from Eastern Asia and North America. Thirty obstructive sleep apnea (OSA) patients were randomly selected from administrative and research oral health data archived at two dental faculties in China and Canada. To assess the reliability of the protocol, two observers performed nasal cavity volume measurement twice with a 10-day interval, using Amira software (v4.1, Visage Imaging Inc., Carlsbad, CA). The accuracy study used a computerized tomography (CT) scan of an OSA patient, who was not included in the study sample, to fabricate an anthropomorphic phantom of the nasal cavity volume with known dimensions (18.9 ml, gold standard). This phantom was scanned using one NewTom 5G (QR systems, Verona, Italy) CBCT scanner. The nasal cavity was segmented based on CBCT images and converted into standard tessellation language (STL) models. The volume of the nasal cavity was measured on the acquired STL models (18.99 ± 0.066 ml).

RESULTS

The intra-observer and inter-observer intraclass correlation coefficients for the volume measurement of the nasal cavity were 0.980-0.997 and 0.948-0.992 consecutively. The nasal cavity volume measurement was overestimated by 1.1%-3.1%, compared to the gold standard.

CONCLUSIONS

The semi-automatic segmentation protocol of the nasal cavity in patients with sleep apnea and by using cone beam computed tomography is reliable and accurate.

CLINICAL RELEVANCE

This study provides a reliable and accurate protocol for segmentation of nasal cavity, which will facilitate the clinician to analyze the images within nasoethmoidal region.

The Influence of Slice Thickness, Sharpness, and Contrast Adjustments on Inferior Alveolar Canal Segmentation on Cone-Beam Computed Tomography Scans: A Retrospective Study

This retrospective study aims to investigate the impact of cone-beam computed tomography (CBCT) viewing parameters such as contrast, slice thickness, and sharpness on the identification of the inferior alveolar nerve (IAC). A total of 25 CBCT scans, resulting in 50 IACs, were assessed by two investigators using a three-score system (good, average, and poor) on cross-sectional images. Slice thicknesses of 0.25 mm, 0.5 mm, and 1 mm were tested, along with varying sharpness (0, 6, 8, and 10) and contrast (0, 400, 800, and 1200) settings. The results were statistically analyzed to determine the optimal slice thickness for improved visibility of IAC, followed by evaluating the influence of sharpness and contrast using the optimal thickness. The identified parameters were then validated by performing semi-automated segmentation of the IACs and structure overlapping to evaluate the mean distance. Inter-rater and intra-rater reliability were assessed using Kappa statistics, and inferential statistics used Pearson's Chi-square test. Inter-rater and intra-rater reliability for all parameters were significant, ranging from 69% to 83%. A slice thickness of 0.25 mm showed consistently "good" visibility (80%). Sharpness values of zero and contrast values of 1200 also demonstrated high frequencies of "good" visibility. Overlap analysis resulted in an average mean distance of 0.295 mm and a standard deviation of 0.307 mm across all patients' sides. The study revealed that a slice thickness of 0.25 mm, zero sharpness value, and higher contrast value of 1200 improved the visibility and accuracy of IAC segmentation in CBCT scans. The individual patient's characteristics, such as anatomical variations, decreased bone density, and absence of canal walls cortication, should be considered when using these parameters.

The impact of teeth and dental restorations on gray value distribution in cone-beam computer tomography: a pilot study

PURPOSE

To investigate the influence of teeth and dental restorations on the facial skeleton's gray value distributions in cone-beam computed tomography (CBCT).

METHODS

Gray value selection for the upper and lower jaw segmentation was performed in 40 patients. In total, CBCT data of 20 maxillae and 20 mandibles, ten partial edentulous and ten fully edentulous in each jaw, respectively, were evaluated using two different gray value selection procedures: manual lower threshold selection and automated lower threshold selection. Two sample t tests, linear regression models, linear mixed models, and Pearson's correlation coefficients were computed to evaluate the influence of teeth, dental restorations, and threshold selection procedures on gray value distributions.

RESULTS

Manual threshold selection resulted in significantly different gray values in the fully and partially edentulous mandible. (p = 0.015, difference 123). In automated threshold selection, only tendencies to different gray values in fully edentulous compared to partially edentulous jaws were observed (difference: 58-75). Significantly different gray values were evaluated for threshold selection approaches, independent of the dental situation of the analyzed jaw. No significant correlation between the number of teeth and gray values was assessed, but a trend towards higher gray values in patients with more teeth was noted.

CONCLUSIONS

Standard gray values derived from CT imaging do not apply for threshold-based bone segmentation in CBCT. Teeth influence gray values and segmentation results. Inaccurate bone segmentation may result in ill-fitting surgical guides produced on CBCT data and misinterpreting bone density, which is crucial for selecting surgical protocols. Created with BioRender.com.

Three-Dimensional Assessment and Comparison of the Maxillary Tuberosity Between Skeletal and Dental Class I and Class II Adults in Maxillary Third Molar Agenesis Using Cone Beam Computed Tomography: A Descriptive Cross-Sectional Human Study

AIM AND OBJECTIVE

The objective of this study was to assess and compare the dimensions (width (W), height (H), and length (L)) of the tuberosity distal to maxillary permanent second molar in individuals with skeletal and dental Class I and Class II malocclusions who had maxillary third molar agenesis.

METHODOLOGY

Cone beam computed tomography (CBCT) was used to measure the left (L) and right (R) anatomical tuberosity dimensions in three dimensions using the WillMaster software (HDX WILL Corporation, Korea). The measurements were compared between Class I (n = 35) and Class II (n = 35) normo-hypodivergent adult subjects. The dimensions were measured at regular 2 mm intervals from the cementoenamel junction (CEJ) and distovestibular root of the maxillary second molar in terms of the width (e.g., W1, W2, and W3), height (e.g., H1, H2, and H3), length (e.g., L1, L2, and L3) to the posterior limit of the tuberosity. Statistical analysis included descriptive statistics, Mann-Whitney U tests, and intraclass correlation coefficient tests.

RESULTS

The width of the tuberosity at LW0, LW1, and LW2 was significantly higher in Class I compared to that in Class II. The right tuberosity in Class II showed significantly higher values in height at all reference points. The right tuberosity at RL0 and RL1 exhibited significantly higher values in the length of the Class II group compared to the Class I group.

CONCLUSIONS

The dimensions of the maxillary tuberosity (width, height, and length) varied between the Class I and Class II groups. Wider maxillary tuberosities were observed in the Class I group, while the Class II group had greater height and length dimensions of the tuberosity.

Factors Associated with Patients' Rejection of Root Canal Treatment in a Tertiary Hospital, Southwest Nigeria: A Pilot Survey

Objective

Root canal treatment (RCT) is a major procedure in dentistry. It aims to relieve the pain of pulpal origin and maintain the affected tooth as a functional unit on the arch. Despite these achievable goals, RCT is sometimes rejected by patients. This study, therefore, sought to assess the reasons for rejection in patients planned for endodontic/RCT.

Materials and Methods

This was a cross-sectional pilot survey of patients planned for RCT using a self-administered questionnaire. The questionnaire included sociodemographics, the Index for Dental Anxiety and Fear (IDAF-4C), and questions to assess the reasons for rejection of endodontic treatment. Data collected were analysed with IBM Statistical Package for the Social Sciences software program, version 23.0. Descriptive statistics were used; chi-square was used to test the association between categorical variables. Statistical significance was set at P ≤ 0.05.

Result

Thirty-one patients between the age range of 16 and 81 years, with a mean age of 38.16 ± 17.87, participated in the survey. Only nine (29.03%) of the participants declined to have the treatment. The majority 6(66.7%), and 7(77.8%) of those that refused the treatment did so, due to fear of drilling (P = 0.014) and cost of treatment (P = 0.001), respectively. Mean IDAF-4C was 1.86 ± 0.9 (standard deviation).The rejection was, however, not affected by past experience, the risk of taking multiple radiographs, and the number of hours or visits for the procedure.

Conclusion

The cost of treatment and fear of drilling were the major reasons for the rejection of RCT in this study. Therefore, there is a need to further look into making endodontic treatment a more comfortable, less costly, and less fear-provoking procedure for patients.

A Correlation Analysis between Arch Width and Molar Inclination Using Cone-Beam Computed Tomography Transverse Measurements: A Cross-Sectional Study

A new era in 3-dimensional analysis has begun with the use of cone-beam computed tomography (CBCT) in orthodontics, which promises to provide a more thorough understanding of the craniofacial skeletal architecture. This study aimed to investigate the correlation between the transverse basal arches discrepancy and dental compensation by utilizing CBCT width analysis. An observational study was conducted to retrospectively review 88 CBCT scans of patients presented to dental clinics from 2014 to 2020 obtained from the Planmeca Romexis x-ray system at three centers. Dental compensation data across normal and narrow maxillae were analyzed and a Pearson correlation was used to find the relationship between molar inclination and width difference. Significant maxillary molar compensation differences were observed between the normal maxilla and narrow maxilla group, where the amount of dental compensation (164.73 ± 10.15) was higher in the narrow maxilla group. A significant negative correlation (r = -0.37) was observed between width difference and maxillary molar inclination. Maxillary molars were tipped buccally to compensate for the reduced maxillary arch width. These findings are important to determine the amount of needed maxillary expansion taking into account the buccal inclination while treating cases.

Does Head and Neck Posture Affect Cone-Beam Computed Tomography Assessment of the Upper Airway?

PURPOSE

Radiographic analysis is often used as a screening tool to assess for risk of sleep-related breathing disorders. This study aimed to address 2 questions: (1) Does head posture significantly affect the minimum cross-sectional area (MCA)? and (2) Is the NBC3 (nasion-basion-C3) angle a reliable measurement to control for alteration of head position in cone-beam computed tomography (CBCT) scans?

METHODS

Study design: prospective cohort study.

SETTING

Private practices affiliated with a research institution.

PARTICIPANTS

convenience sample of adult volunteers.

VARIABLES

CBCT scans were taken in 2 conditions: baseline (natural head position, NHP) and 1 of 5 experimental conditions (head tilted up, head tilted down, sitting vs standing, use of chin-rest, and swallow variation). For the primary aim of our study, the primary predictor variable was head posture and the main outcome variable was percentage change in MCA. For the secondary aim, the primary predictor variable was head posture and the main outcome variable was degree change in NBC3 angle.

RESULTS

Ninety subjects were included (age 40.7 ± 13.7 years, 70% female). Mean NBC3 at baseline was 112.4 ± 8.3°. Head tilted down significantly decreased (-41.4 ± 18.5 mm², P = .03∗) and head tilted up significantly increased MCA (+147.4 ± 43.3 mm², P = .0018∗). Head tilted down significantly reduced the NBC3 angle measurement (-10.5 ± 6.8°, P = .006) and head tilted up significantly increased the NBC3 angle measurement (+14.4 ± 5.8°, P = .0004). A quadratic regression model was fitted with moderately strong correlation (R² = 0.54) showing an exponential effect of small changes in the NBC3 angle on MCA, P < .0001. The model predicts that increasing NBC3 by +5 and + 10° resulted in MCA changes of +25% and +88%, whereas a decrease in NBC3 by -5 and -10° results in MCA changes of -21% and -23%, respectively.

CONCLUSION

Alterations in head posture significantly affect the MCA of the upper airway on CBCT. The NBC3 angle can be used to reliably assess changes in cranio-cervical extension and validate comparisons of MCA between CBCT scans for the same patient. A standardized protocol for CBCT acquisition is proposed.

Establishment of Diagnostic Reference Levels in Cone Beam Computed Tomography Scans in the United Arab Emirates

This study aimed to address the knowledge gap in assessing the radiation doses from cone beam computed tomography (CBCT) procedures, establishing a typical value, and estimating effective and organ doses. A total of 340 patients aged 18-80 years were included in this study. Organ doses were estimated using VirtualDose IR software. The typical values were based on median values estimated as 1000 mGy cm². The mean ED (µSv) per procedure was 149.5 ± 56, and the mean of the peak skin dose during the CBCT examination was 39.29 mGy. The highest organ dose was received by the salivary glands (2.71 mGy), the extrathoracic region (1.64 mGy), thyroid (1.24 mGy) and eyes (0.61 mGy). The patients' doses were higher than in previous studies. Staff awareness, education, training and dose optimisation are highly recommended. With the establishment of local DRLs, patient dosages can be reduced successfully without compromising image quality.

Three-dimensional digital applications for implant space planning in orthodontics: A narrative review

In the digital dentistry era, new tools, algorithms, data science approaches, and computer applications are available to researchers and clinicians. However, there is also a strong need for better knowledge and understanding of multisource data applications, including three-dimensional imaging information such as cone-beam computed tomography images and digital dental models for multidisciplinary cases. In addition, artificial intelligence models and automated clinical decision systems are rising. The clinician needs to plan the treatment based on state-of-the-art diagnosis for better and more personalized treatment. This article aimed to review basic concepts and the current panorama of digital implant planning in orthodontics, with open-source and closed-source tools for assessing cone-beam computed images and digital dental models. The visualization and processing of the three-dimensional data allow better implant planning based on bone conditions, adjacent teeth and root positions, and the prognosis of the case. We showed that many tools for assessment, segmentation, and visualization of cone-beam computed tomographic images and digital dental models could facilitate the treatment planning of patients needing implants or space closure. The tools and approaches presented are toward personalized treatment and better prognosis, following the path to a more automated clinical decision system based on multisource three-dimensional data, artificial intelligence models, and digital planning. In summary, the orthodontist needs to analyze each patient individually and use different software or tools that better fit their practice, allowing efficient treatment planning and satisfactory results with an adequate prognosis.

Improving performance of deep learning models using 3.5D U-Net via majority voting for tooth segmentation on cone beam computed tomography

Deep learning allows automatic segmentation of teeth on cone beam computed tomography (CBCT). However, the segmentation performance of deep learning varies among different training strategies. Our aim was to propose a 3.5D U-Net to improve the performance of the U-Net in segmenting teeth on CBCT. This study retrospectively enrolled 24 patients who received CBCT. Five U-Nets, including 2Da U-Net, 2Dc U-Net, 2Ds U-Net, 2.5Da U-Net, 3D U-Net, were trained to segment the teeth. Four additional U-Nets, including 2.5Dv U-Net, 3.5Dv5 U-Net, 3.5Dv4 U-Net, and 3.5Dv3 U-Net, were obtained using majority voting. Mathematical morphology operations including erosion and dilation (E&D) were applied to remove diminutive noise speckles. Segmentation performance was evaluated by fourfold cross validation using Dice similarity coefficient (DSC), accuracy, sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV). Kruskal-Wallis test with post hoc analysis using Bonferroni correction was used for group comparison. P < 0.05 was considered statistically significant. Performance of U-Nets significantly varies among different training strategies for teeth segmentation on CBCT (P < 0.05). The 3.5Dv5 U-Net and 2.5Dv U-Net showed DSC and PPV significantly higher than any of five originally trained U-Nets (all P < 0.05). E&D significantly improved the DSC, accuracy, specificity, and PPV (all P < 0.005). The 3.5Dv5 U-Net achieved highest DSC and accuracy among all U-Nets. The segmentation performance of the U-Net can be improved by majority voting and E&D. Overall speaking, the 3.5Dv5 U-Net achieved the best segmentation performance among all U-Nets.

Numerical Analysis of Zirconium and Titanium Implants under the Effect of Critical Masticatory Load

Dental implants have become an alternative to replace the teeth of people suffering from edentulous and meet the physiological and morphological characteristics (recovering 95% of the chewing function). The evolution and innovation of biomaterials for dental implants have had a trajectory that dates back to prehistory, where dental pieces were replaced by ivory or seashells, to the present day, where they are replaced by metallic materials such as titanium or ceramics such as zirconium or fiberglass. The numerical evaluation focuses on comparing the stress distribution and general displacement between different dental implants and a healthy tooth when applying a force of 850 N. For the analysis, a model of the anatomical structure was developed of a healthy tooth considering three essential parts of the tooth (enamel, dentin, and pulp). The tooth biomodel was established through computed tomography. Three dental implant models were considered by changing the geometry of the abutment. A structural simulation was carried out by applying the finite element method (FEM). In addition, the material considered for the analyses was zirconium oxide (ZrO2), which was compared against titanium alloy (Ti6Al4V). The analyses were considered with linear, isotropic, and homogeneous properties. The variables included in the biomodeling were the modulus of elasticity, Poisson's ratio, density, and elastic limit. The results obtained from the study indicated a significant difference in the biomechanical behavior of the von Mises forces and the displacement between the healthy tooth and the titanium and zirconium implant models. However, the difference between the titanium implant and the zirconium implant is minimal because one is more rigid, and the other is more tenacious.

Effect of the Field of View Size on CBCT Artifacts Caused by the Presence of Metal Objects in the Exomass

Materials and Methods

In this in vitro experimental study, titanium implants, teeth with cobalt-chromium (Co-Cr) intracanal posts, and teeth with mesio-occluso-distal (MOD) amalgam restorations were placed in an empty socket of the extracted third molar of a human mandible. These metallic materials were differently arranged in the exomass (zone outside of the FOV). A polypropylene tube containing dipotassium phosphate was placed in the empty socket of the right canine tooth in a dry human mandible. CBCT scans were taken with a NewTom VGI (Verona, Italy) scanner using a 6 × 6 cm and an 8 × 8 cm FOV. The histogram tool of OnDemand software (Cybermed, Seoul, Korea) was used to select circles with a 1.5 mm diameter as the (ROI) at the center of the homogenous solution of dipotassium phosphate tube on the axial plane. The mean gray value (GV) and its standard deviation (SD) in the region of interest (ROI) were calculated (P > 0.05). The data were analyzed by SPSS 26.

Results

The reduction in the size of the FOV significantly decreased the mean GV (P < 0.001). Metal objects in the exomass significantly decreased the mean GV (P < 0.001), and minimum mean GV and maximum SD were recorded for amalgam, followed by Co-Cr intracanal posts, and titanium implants. The unilateral presence of a metal object was associated with a higher mean GV and lower SD (P < 0.001).

Conclusion

Using a smaller FOV increases the size of the exomass, which may negatively affect the image quality. Metal objects in the exomass decrease the GV of CBCT scans and adversely affect the image quality.

A Novel Method to Combine Maxilla-Based Coordinate System and Mandibular Voxel-Based Superimposition with Cone-Bean Computed Tomography

Background: The objective of this study was to propose a method that combines a maxilla-based coordinate system and mandibular voxel-based superimposition for an accurate evaluation of mandibular structural and positional changes and a direct comparison between maxillary and mandibular structural changes with the same 3D vectors. Methods: Mandibular voxel-based superimposition was firstly performed to reorient the mandibles and eliminate the mandibular positional changes. Then, a maxilla-based coordinate system was constructed with four maxillary skeletal landmarks (ANS, PNS, OrL and OrR). After settling the reoriented mandibles into this coordinate system, the mandibular structural changes were accurately evaluated. To assess the accuracy and reproducibility of this method, CBCT images of a skull specimen before and after orthodontic treatment (which was simulated by rearranging the skull and the mandible) were collected. Five mandibular skeletal landmarks, three mandibular dental landmarks and two mandibular measurement planes of this skull were used to evaluate the linear and angular changes in the mandibular structures. Results: There were significant differences in the linear and angular measurements of the mandibular structures of the skull (p ˂ 0.05), which indicated mandibular positional changes after orthodontic treatment. After mandibular voxel-based superimposition, there were no significant differences in the linear and angular measurements of mandibular structures, which indicated that the mandibular positional changes were eliminated. The intraclass correlation coefficient (ICC) value of the inter- and intra-observer agreement of all measurements was 0.99. Conclusions: This method has proven advantages in terms of accuracy, reproducibility and validity; with this method, mandibular structural and positional changes can be accurately evaluated and maxillary and mandibular structural changes can be directly compared with same 3D vectors.

Prevalence and Characterization of bifid mandibular Canal Using Cone Beam Computed Tomography: A Retrospective Cross-Sectional Study in Saudi Arabia

Aim

The purpose of this study is to determine the prevalence and morphological characteristics of the bifid mandibular canal in a Saudi Arabian subpopulation, to aid in preventing surgical complications near the mandibular canal.

Patients and Methods

Using CBCT images obtained from the Radiology unit database in a University Hospital Clinics. A total of 488 CBCT images were investigated (244 Female – 178 Male). In the present study, the Naitoh classification was used to categorize the bifid mandibular canal into the following types: 1) Retromolar canal; 2) Dental canal; 3) Forward canal (with or without confluence); and 4) Buccolingual canal. Additional variation (Trifid canal) was included. All CBCTs were assessed in coronal, sagittal, axial, as well as panoramic views using specialized software.

Results

The prevalence of BMC was 28.7% (95% CI, 24.5 to 33.2), Gender (p = 0.404) and age (p = 0.654) had no statistical significances, laterality of BMC, patients with unilateral BMC were significantly older than those with bilateral BMC (mean ± SD ages of 40.5 ± 13.5 and 32.9 ± 13.8, respectively, p = 0.009). About two-thirds (67.5%) of the investigated BMC cases were found unilateral. The most common reported type of BMC was retromolar canal.

Conclusion

The incidence of bifid mandibular canal using CBCT is considered relatively high in Saudi Arabian subpopulation, with the most common type was the retro-molar canal.

Evaluation of Root Canal Configuration of Maxillary and Mandibular First Molar by CBCT: A Retrospective Cross-Sectional Study

Adequate knowledge of root canal morphology along with its probable variations is imperative to acquire successful endodontic treatment. This retrospective cross-sectional study aimed to investigate the root canal configuration of maxillary and mandibular first molar using Cone-Beam Computed Tomography (CBCT) among patients in Al-Ahsa region, Saudi Arabia. A total of 377 samples were included, out of which 123 CBCT (I-CAT Vision QTM) scans with intact all first permanent molars were selected in this study and scanned in sagittal, axial, and coronal views by using BlueSkyPlan software. The number of canals in each root and their configuration according to the Vertucci classification system was evaluated. Statistical analysis was analyzed using SPSS version 21 (IBM). Chi-square test was applied to evaluate the association of root canal morphology and mandibular and maxillary first molars with respect to gender. Out of 123 CBCT scans, 59 (48.0%) were males and 64 (52.0%) were females; the mean age was 26.95 ± 10.65 years. The mesiobuccal root of bilateral maxillary first molar had Type-I (87.0%) of Vertucci classification followed by Type-IV (9.8%). Additionally, all mesiobuccal roots (100%) of the left mandibular first molar had Type-I of Vertucci’s classification. A significant association has been observed between gender and a number of canals in bilateral maxillary first molars. Females showed a significantly higher prevalence of three-root canal configuration in maxillary first molars of both sides compared four canals found most commonly in males (p = 0.004). This study concluded that the majority of maxillary and mandibular permanent first molars had three roots and three canals with Type-I Vertucci’s classification in patients belonging to the Al-Ahsa region of the Saudi Arabia. It was also proved that gender is significantly associated with the number of canals in a bilateral maxillary molar.

Can Weightbearing Cone-beam CT Reliably Differentiate Between Stable and Unstable Syndesmotic Ankle Injuries? A Systematic Review and Meta-analysis

BACKGROUND

Ankle injuries are common presentations to the emergency department and may lead to syndesmotic instability. These have a high socioeconomic burden due to prolonged rehabilitation, chronic pain, and posttraumatic arthritis. Early diagnosis is essential to minimize these complications, and the assessment of instability in the clinical setting is often limited by pain and clinician experience. Cross-sectional imaging of the distal syndesmosis accurately evaluates the syndesmosis through abnormal bony relationships, which in the presence of instability, worsens during physiological loading. Cone-beam CT (CBCT) has gained popularity in the diagnosis of these injuries because it enables syndesmotic assessment under weightbearing conditions, it mitigates the high radiation dose, and it is time-efficient.

QUESTIONS/PURPOSES

The purposes of this systematic review were: (1) to establish normal values for weightbearing CBCT of the syndesmosis in uninjured ankles and ascertain interobserver reliability and (2) to identify the impact of weightbearing on the syndesmosis in patients with occult ankle injuries and assess the effect of patient demographics on these metrics.

METHODS

This systematic review was reported in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and registered in PROSPERO (ID CRD42021248623). MEDLINE, PubMed, Embase, and Emcare databases were searched for studies assessing for syndesmotic instability, of which 307 studies were screened and 11 studies with 559 ankles in 408 uninjured patients and 151 patients with syndesmotic instability were included. All patients 18 years of age or older presenting with unilateral ankle injuries who underwent weightbearing CBCT for the diagnosis of an occult fracture or syndesmotic instability compared with the uninjured contralateral side were included. A control group of uninjured ankles was identified during weightbearing CBCT performed for other indications such as forefoot or midfoot injuries. Methodological assessment of the studies was performed using the Risk of Bias In Non-randomized Studies (ROBINS-1) tool and most included studies had a low risk of bias. Thus, a random-effects restricted maximum likelihood ratio model was used.

RESULTS

In the uninjured ankle, the mean area of the tibiofibular syndesmosis was 112.5 ± 7.1 mm 2 , which increased to 157.5 ± 9.6 mm 2 after injury when compared with uninjured ankles with a standardized mean difference of 29.5 (95% confidence interval 19.5 to 39.5; p < 0.01), and an excellent interobserver agreement (κ = 1.0 [95% CI 0.9 to 1.0]). However, syndesmosis volume decreased with age (β = -0.76; p = 0.04), and therefore, has a negative association with increasing age.

CONCLUSION

Our study has shown that the syndesmotic area is the most reliable parameter in the assessment of syndesmotic injuries because it increases in the presence of instability during weightbearing status. It is a composite measurement that could potentially allow clinicians to use weightbearing CBCT as an adjunct when there is a clinical suspicion of syndesmotic instability. Thus, weightbearing CBCT has the potential of being diagnostic of syndesmotic instability and should be evaluated against current radiological modalities to evaluate its accuracy.

LEVEL OF EVIDENCE

Level IV, prognostic study.

Criteria for the Classification of the Interradicular Septum Shape in Maxillary Molars with Clinical Importance for Prosthetic-Driven Immediate Implant Placement

The aim of this study was to use cone-beam computed tomography (CBCT) to evaluate the morphometric properties of the interradicular septum (IRS) in the maxillary molar region that may be indicative for prosthetic-driven implant placement. Following the repetitive algorithm based on the visual identification of IRS shapes, we described the following IRS shapes: arrow, boat, drop, and palatal and buccal convergence. The incidence of IRS shapes showed significant differences for the first and second maxillary molars (the highest frequency for the arrow shape, and the lowest for the drop shape) with no significant difference between the molars. The most prominent width indicative for implant placement was observed in the palatal convergence shape, whereas the height criteria were the most satisfying in the buccal convergence-shaped IRS for both molars. Apart from the parameters in the coronal view, the image analysis in the axial view revealed that IRS surface area, required for the implant placement, was the most prominent in the palatal convergence shape for the first, and boat shape for the second molars. Our results showed the benefits of CBCT diagnostics in posterior maxilla morphometric analysis. IRS shape classification may be helpful in achieving more rapid and accurate planning for interventions in this region.

Evaluation of the association between osteoporosis and periodontitis in postmenopausal women: A clinical and radiographic study

Background

This study aimed to assess the relationship between the osteoporotic condition and periodontitis in postmenopausal women.

Materials and Methods

Ninety-four women aged 50-80 years were studied in this cross-sectional study. Bone mineral density (BMD) of lumbar vertebra BMD (LBMD), total hip BMD (HBMD), and neck of femur BMD (NBMD) was assessed using standardized dual-energy X-ray absorptiometry (DXA) (normal: T-score ≥-1, osteopenic: -2.5 ≤ t-score <-1, osteoporotic: T-score <-2.5). Bleeding point index (BI), O'Leary plaque index (PI), and clinical attachment loss (CAL) were recorded. Cementoenamel junction, alveolar-crest distance (CEJ-AC) was measured from cone-beam computed tomography images. Periodontitis severity was represented by CAL and CEJ-AC distance. One-way analysis of variance followed by Post hoc Tukey was performed for examining differences among the groups for different variables. Pearson correlation coefficient® and backward regression analysis were used to investigate the effect of confounding variables on CEJ-AC as the dependent variable. Significance was considered at P < 0.05.

Results

Mean CEJ-AC was significantly higher in the osteoporotic and osteopenic groups compared to the normal group (P = 0.001). There was a significant positive correlation between CEJ-AC and NBMD and LBMD (P < 0.001). The associations between LBMD and CEJ-AC existed even after adjusting for confounding factors (P = 0.002). The differences in BI, PI, and CAL were not statistically different between the groups (P > 0.05).

Conclusion

Although osteoporosis is not the main cause of periodontitis, it can indirectly affect periodontal status by increasing CEJ-AC. Early diagnosis of osteoporosis followed by early referral to a dentist for the treatment of potential existing periodontal diseases is important to avoid complications among postmenopausal women.

Convolutional neural network for automatic maxillary sinus segmentation on cone-beam computed tomographic images

An accurate three-dimensional (3D) segmentation of the maxillary sinus is crucial for multiple diagnostic and treatment applications. Yet, it is challenging and time-consuming when manually performed on a cone-beam computed tomography (CBCT) dataset. Recently, convolutional neural networks (CNNs) have proven to provide excellent performance in the field of 3D image analysis. Hence, this study developed and validated a novel automated CNN-based methodology for the segmentation of maxillary sinus using CBCT images. A dataset of 264 sinuses were acquired from 2 CBCT devices and randomly divided into 3 subsets: training, validation, and testing. A 3D U-Net architecture CNN model was developed and compared to semi-automatic segmentation in terms of time, accuracy, and consistency. The average time was significantly reduced (p-value < 2.2e−16) by automatic segmentation (0.4 min) compared to semi-automatic segmentation (60.8 min). The model accurately identified the segmented region with a dice similarity co-efficient (DSC) of 98.4%. The inter-observer reliability for minor refinement of automatic segmentation showed an excellent DSC of 99.6%. The proposed CNN model provided a time-efficient, precise, and consistent automatic segmentation which could allow an accurate generation of 3D models for diagnosis and virtual treatment planning.

Cone-Beam Computed Tomography: A New Tool on the Horizon for Forensic Dentistry

Teeth and bones of calvarium are important structures from a forensic point of view, as they are extremely resilient to destruction or decomposition, even under temperature variations. Radiology is inevitably an important tool in forensic investigations. Maxillofacial radiology provides a considerable amount of information for the identification of remains and evidence in case of legal matters. The advent of cone-beam computed tomography (CBCT) in the arena of maxillofacial 3D imaging has contributed immensely to forensic science such as the age estimation through teeth, analysis of bite marks, determination of race and sex, etc. The advantages of accuracy in imaging the anatomy, digitized technology favoring easier comparison of records and storage of records for a longer period, cost reduction, dose reduction, and easier portability have made it an unavoidable adjunct in forensic investigations. The aim of this paper is to review and highlight the importance of CBCT in successful forensic identification and analysis. This review is written to address the various aspects of CBCT as a recently developed technology that may be very useful in some forensic contexts, based on searches for current studies in the literature using PubMed, Scopus, Web of Science, and Google Scholar databases, to identify studies published since inception to December 2021, with no language restriction. In conclusion, CBCT is an accessible 3D imaging technology with many applications, one of them being in forensic sciences.

A Narrative Review on Current Diagnostic Imaging Tools for Dentomaxillofacial Abnormalities in Children

The current review narrates the findings and discusses the available diagnostic tools for detecting structural abnormalities. The review discusses several diagnostic tools, such as magnetic resonance imaging, cone beam computed tomography, multi detector row CT and positron emission tomography. The vital findings and comparative analysis of different diagnostic tools are presented in this review. The present review also discusses the advent of newer technologies, such as the HyperionX9 scanner with less field of view and 18F-FDG PET/CT (positron emission tomography with 2-deoxy-2-[fluorine-18] fluoro-D-glucose, integrated with computed tomography), which can give more efficient imaging of dentomaxillofacial structures. The discussion of effective comparative points enables this review to reveal the available diagnostic tools that can be used in the detection of dentomaxillofacial abnormalities in the pediatric population. The advantages and disadvantages of each tool are discussed, and the findings of past publications are also presented. Overall, this review discusses the technical details and provides a comparative analysis of updated diagnostic techniques for dentomaxillofacial diagnosis.

Assessment of Maxillary Molars Interradicular Septum Morphological Characteristics as Criteria for Ideal Immediate Implant Placement—The Advantages of Cone Beam Computed Tomography Analysis

The aim of this study was to evaluate the interradicular septum bone morphometric characteristics using cone beam computed tomography (CBCT) images, as well as to establish quantitative shortcuts to allow clinicians to make a faster and more reliable plan for immediate implant placement in the maxillary molars area. This retrospective quantitative study was conducted on CBCT images obtained from 100 patients. The morphometric analysis of the maxillary molars region was based on the parameters obtained on the sagittal and axial slices. The analysis performed on sagittal slices showed that the first maxillary molars had a wider interradicular septum when compared to the second molars, but the septum height in the first molars was significantly below the height in the second maxillary molars. The axial CBCT slices analysis showed that both interradicular septum perimeter and surface area were significantly more pronounced in the first than in the second maxillary molars. The interradicular furcation angle significantly correlated with the surface area (positively) and septum height (negatively) for both molars. The results of this study may recommend CBCT image analysis as a useful tool in predefining the circumstances that can allow for substantially better planning of immediate implant placement procedures in the region of maxillary molars.

Morphological Characteristics of Maxillary Molars Interradicular Septum and Clinical Implications - What do We Know So Far?

The interradicular septum describes area in the root furcation that separate alveoli of multi-rooted teeth. The shape and dimension depend of the topography of the extraction socket, the geometry of residual root and anatomy of molars alveoli. The clinical implications of this anatomic structure may be used in oral surgery resection procedures, periodontology and implantology. There is an opinion from the surgical and prosthodontic side that center of interradicular septum may be adequate place for immediate implantation. The aim of this study was to investigate morphological characteristics and clinical implications of upper molars interradicular septum. The studies showed that interradicular septum is important for success of resection surgery procedures: hemi-section, bisection and root amputation. It’s reported that furcation involvement in periodontal disease is clinical sign for severe bone loss. By reviewing the available literature for immediate implantation, it’s reported the clinical implications for diagnostical plan (pre-intervention), presurgical (pre-instrumentation) and intraoperative evaluation of interradicular septum for immediate implantation. The cone beam computed tomography analyze study presented mean values of septum height and wide for hypothetical plan of immediate implant placement. The presurgical studies evaluate how to assure preservation of septum and safe implant position in center of septum. The research showed varies therapy modalities that can be used, and how to choose right therapy according the socket type and initial septum width classification. According to observation of studies results, other researches should be considered for CBCT anatomical structure analyze and measures of interradicular septum for immediate implantation planning.

CTIMS: Automated Defect Detection Framework Using Computed Tomography

Non-Destructive Testing (NDT) is one of the inspection techniques used in industrial tool inspection for quality and safety control. It is performed mainly using X-ray Computed Tomography (CT) to scan the internal structure of the tools and detect the potential defects. In this paper, we propose a new toolbox called the CT-Based Integrity Monitoring System (CTIMS-Toolbox) for automated inspection of CT images and volumes. It contains three main modules: first, the database management module, which handles the database and reads/writes queries to retrieve or save the CT data; second, the pre-processing module for registration and background subtraction; third, the defect inspection module to detect all the potential defects (missing parts, damaged screws, etc.) based on a hybrid system composed of computer vision and deep learning techniques. This paper explores the different features of the CTIMS-Toolbox, exposes the performance of its modules, compares its features to some existing CT inspection toolboxes, and provides some examples of the obtained results.

The use of cone-beam computed tomography (CBCT) in radiocarpal fractures: a diagnostic test accuracy meta-analysis

OBJECTIVE

Occult radiocarpal fractures often present a diagnostic challenge to the emergency department. Accurate diagnosis of these injuries is crucial as a missed fracture can lead to significant morbidity. Cone-beam CT (CBCT) scan is a novel imaging modality, with minimal radiation exposure and comparatively fast acquisition time. Our aim was to evaluate its use in the diagnosis of cortical fractures in the upper limb extremity.

MATERIALS AND METHODS

We conducted a systematic review of literature and included all studies that evaluated the use of CBCT in the diagnosis of radiocarpal fractures. We used a mixed-effects logistic regression bivariate model to estimate the summary sensitivity and specificity and constructed hierarchical summary receiver operative characteristic curves (HSROC).

RESULTS

We identified 5 studies, with 439 patients, and observed CBCT to be 87.7% (95% CI 77.6-93.6) sensitive and 99.2% (95% CI 92.6-99.9) specific for scaphoid fractures. For carpal fractures, CBCT was observed to have a pooled sensitivity and specificity of 90.6% (95% CI 72.7-97.2) and 100% (95% CI 99-100) respectively. For distal radius fractures, CBCT sensitivity was 90% (95% CI 67-98) and specificity was 100% (95% CI 10-100). The overall inter-rater agreement effect was shown to be 0.89 (95% CI 0.82-0.96), which is deemed to be almost perfect.

CONCLUSION

CBCT is an accurate diagnostic tool for occult radiocarpal cortical fractures, which could replace or supplement radiographs. We believe CBCT has a promising role in the acute radiocarpal fracture diagnostic algorithm in both emergency and trauma departments.

[Evaluation of the morphology of the nasopalatine canal using cone beam computed tomography]

OBJECTIVE

High precise evaluation of the nasopalatine canal morphology is essential to perform detailed diagnosis and treatment plans in implantology and the orthodontic field. We aimed to study morphometric analysis measurements of the nasopalatine canal.

MATERIAL AND METHODS

In this cross-sectional study, maxillary CBCT images from 125 patients were evaluated in the Maxillofacial Radiology department between 2014-2021. Sagittal views were assessed to determine nasopalatine canal morphology and dimensions. The difference in canal diameter and length between genders was evaluated using an One Way ANOVA test.

RESULTS

There was no significant sex difference among all 125 cases in nasopalatine canal diameter, length, anterior bone plate width. The average length of the nasopalatine canal was 16.49±2.8 mm in male, 16.20±2.9 mm in female, incisive foramen diameter in the sagittal plane was 4.04±0.9 mm in male, 4.02±0.9 mm in female, nasopalatine foramen diameter was 4.63±1.4 mm in male, 4.75±1.2 mm in female. The width of the bone anterior to the canal was 5.89±1.4 mm in males, 5.69±1 mm in females.

CONCLUSION

16-48 aged Mongolian average length of the nasopalatine canal was 16.3 mm, and average incisive foramen width was 4.08 mm, the average width of the bone anterior to the canal was 5.76 mm. Anterior retraction treatment for upper incisor root can be done safely without root resorption around 5.5 mm in the premaxillary alveolar bone.

Magnetic resonance imaging versus cone beam computed tomography in diagnosis of periapical pathosis – A systematic review

Objective

The diagnosis of any dental pathology can vary from being simple to challenging. While the use of cone beam computed tomography (CBCT) is well established, magnetic resonance imaging (MRI) remains a proof of concept. This systematic review aims to compare the diagnostic ability of MRI with CBCT in diagnosing periapical pathosis.

Materials and Methods

This systematic search was performed using the electronic databases of MEDLINE, Cochrane Library, Google Scholar, and Science Direct to identify relevant articles from 2010 to 2020. The search terms used were magnetic resonance imaging, cone beam computed tomography, diagnosis, and periapical diseases.

Result

In total, 3218 potentially relevant abstracts and titles were identified. After removing duplicates, 1288 articles were reviewed for titles and abstracts, and 29 articles were selected for full-text reading. From those, 19 articles were finally selected that included original research studies, case reports, and case series and were included for systematic review. Most of the studies included in this review suggested that the combined use of CBCT and MRI is needed for a better and more precise diagnosis of complex periapical pathoses. The main advantage of MRI is its ability to image soft tissues usingnonionizing radiation, and the main disadvantage in the case of CBCT is overdiagnosis of the lesion.

Conclusion

MRI has various advantages over CBCT with similar diagnostic utility. When diagnosing periapical pathogens, both MRI and CBCT are needed for an accurate diagnosis.

Clinical Dilemma and the Role of Cone-Beam Computed Tomography in the Diagnosis of an Unusual Presentation of Central Odontogenic Tumor-A Case Report

Cone beam computed tomography (CBCT) provides a detailed analysis of the dentition and of cortical and medullary bone free of superimposition inherent in radiographs, which are effortlessly plausible, easily available, and relatively inexpensive when compared with other cross-sectional imaging modalities such as computed tomography (CT) and magnetic resonance imaging (MRI). This article presents a case report of a 23-year-old male patient with a complaint of a mass in the right side lower back tooth region for the past 2 and a half months, which had the unusual presentation of prominent exophytic growth masking the central odontogenic tumor, wherein the diagnostic performances of CBCT in unveiling the diagnostic challenge that led to the clinical dilemma is emphasized. Routine radiographs such as orthopantomogram, mandibular occlusal view were taken along with CBCT, which accentuated the precise diagnosis in this case. The lesion was surgically enucleated with curettage and extraction of the involved teeth. CBCT unveiled the classic multilocularity of ameloblastoma, which routine imaging failed to display. CBCT played a pivotal role in counteracting the diagnostic challenges faced and also in distinguishing it from a cystic lesion that was initially deceived by routine two-dimensional radiographs.

Efficient high cone-angle artifact reduction in circular cone-beam CT using deep learning with geometry-aware dimension reduction

High cone-angle artifacts (HCAAs) appear frequently in circular cone-beam computed tomography (CBCT) images and can heavily affect diagnosis and treatment planning. To reduce HCAAs in CBCT scans, we propose a novel deep learning approach that reduces the three-dimensional (3D) nature of HCAAs to two-dimensional (2D) problems in an efficient way. Specifically, we exploit the relationship between HCAAs and the rotational scanning geometry by training a convolutional neural network (CNN) using image slices that were radially sampled from CBCT scans. We evaluated this novel approach using a dataset of input CBCT scans affected by HCAAs and high-quality artifact-free target CBCT scans. Two different CNN architectures were employed, namely U-Net and a mixed-scale dense CNN (MS-D Net). The artifact reduction performance of the proposed approach was compared to that of a Cartesian slice-based artifact reduction deep learning approach in which a CNN was trained to remove the HCAAs from Cartesian slices. In addition, all processed CBCT scans were segmented to investigate the impact of HCAAs reduction on the quality of CBCT image segmentation. We demonstrate that the proposed deep learning approach with geometry-aware dimension reduction greatly reduces HCAAs in CBCT scans and outperforms the Cartesian slice-based deep learning approach. Moreover, the proposed artifact reduction approach markedly improves the accuracy of the subsequent segmentation task compared to the Cartesian slice-based workflow.

Alveolar Bone Ridge Augmentation Using Polymeric Membranes: A Systematic Review and Meta-Analysis

Alveolar bone ridge resorption occurred after natural teeth loss and it can restrict the possibility of dental implants placement. The use of bone regenerative procedures is frequently required. The existing evidence regarding the efficacy of horizontal bone ridge augmentation trough guided bone regeneration (GBR) using polymeric membranes was stated. A systematic review and meta-analysis were performed. Electronic and manual literature searches were conducted. Screening process was done using the National Library of Medicine (MEDLINE by PubMed), Embase, and the Cochrane Oral Health. Included articles were randomized controlled trials and observational studies. Weighted means were calculated. Heterogeneity was determined using Higgins (I2). If I2 > 50% a random-effects model was applied. It was found that the mean of horizontal bone gain was 3.95 mm, ranging from 3.19 to 4.70 mm (confidence interval 95%). Heterogeneity is I2 = 99% (confidence interval 95%) and significance of the random-effects model was p < 0.001. The complications rate was 8.4% and membrane exposure was the most frequent. Through this study, we were able to conclude that the existing scientific evidence suggests that GBR using polymeric membranes is a predictable technique for achieving horizontal bone augmentation, thus, permitting a proper further implant placement.

Imaging studies used as aid in the diagnosis of cleidocranial dysplasia. A review

Cleidocranial dysplasia (CCD), also known as Marie-Sainton syndrome, is a rare disorder of autosomal dominant type that presents specific characteristics at the skeletal and dental level. The diagnosis of CCD is based on clinical and radiographic findings. Panoramic, cephalometric and anterior poster radiographs have been used for its diagnosis in dentistry. However, these radiological techniques have limitations, and advances in technology with new imaging studies such as magnetic resonance imaging (MRI) and ultrasound have emerged, contributing to the diagnosis of CCD. Therefore, the aim of this review was to identify and describe current imaging studies that contribute to both the diagnosis and adequate and efficient treatment planning of CCD, and describe the clinical and radiographic characteristics of patients with this syndrome.

Comparative Reliability Assessment of Tooth Volume Measurement with Different Three-Dimensional Imaging Software

Objective. To evaluate the in vivo tooth volume through VRMesh and 3Matic programs and to compare the measurements to the physical volume. So, the aim of the study was to ensure the reliability and sensitivity of the three-dimensional software (VRMesh and 3Matic) in measuring tooth volume. Material and Methods. The volume of 26 extracted upper first premolars from orthodontic patients who had CBCT before orthodontic treatment were measured. Two different commercial programs, which were VRMesh and 3Matic, were used to calculate the volume of the segmented upper first premolar from CBCT. The in vivo tooth volume was compared to the physical tooth volume to examine the accuracy of the two software in measuring the tooth volume. Results. The difference between the mean of the in vivo and in vitro tooth volume measurements was too small, making it clinically nonsignificant. ANOVA test was used as a statistical tool, and no statistically significant difference was noticed among the measurements. The values were normally distributed when tested for normality by Kolmogorov-Smirnov and Shapiro-Wilk test. $\mathit{P}$ value less than or equal to 0.05 ( $\mathit{P}\le 0.05$ ) was considered statistically significant. Conclusion. The assessment of the in vivo tooth volume measurement with different three-dimensional imaging software (VRMesh and 3Matic) programs in comparison with the tooth physical volume is reliable. The use of a mouse pen during the refining stage of the segmentation may have increased the accuracy of the procedure. The determined in vivo tooth volumes are dependable and can be applied in orthodontic diagnosis and treatment planning.

A novel soft tissue cone-beam computed tomography study in the evaluation of gingival thickness associated with subepithelial connective tissue graft versus acellular dermal matrix in the management of gingival recession: A clinical study

BACKGROUND

Dental esthetic awareness among patients led the clinicians to introduce newer materials and predictable techniques that satisfy the patients' esthetic demands.

AIM

To evaluate and compare the efficacy of subepithelial connective tissue graft (SECTG) and acellular dermal matrix (ACDM) allograft in the treatment of Millers Class I or Class II recession with the determination of gingival thickness using an impertinent method, soft tissue cone-beam computed tomography (ST-CBCT).

MATERIALS AND METHODS

A split-mouth study with a total of ten patients with bilateral Millers class I or class II recession is randomly assigned by a coin toss method as Group I (SECTG) and Group II (ACDM) along with coronally advanced flap. Clinical parameters including recession height (RH), recession width (RW), probing depth, clinical attachment level (CAL), and height of keratinized tissue (HKT) were evaluated at baseline, 90th day, and 180th day for both groups. The thickness of keratinized tissue (TKT) was determined by most reliable, predictable and noninvasive method called ST-CBCT.

RESULTS

Statistically significant reduction in RH and RW, gain in CAL, and increase in HKT and TKT in both Group I and Group II were seen in 90th day and 180th day. However, when both Group I and Group II were compared between 0 and 180th day, the change in RH and RW, gain in CAL, and increase in HKT and TKT did not show any statistically significant change.

CONCLUSION

The present study suggested that root coverage with both SECTG and ACDM is very predictable procedure and it is stable for 6 months. ST-CBCT is a newer dimension in periodontal imaging and will certainly aid clinicians in the execution of various treatment modalities with increased predictability.