No full-text available
To read the full-text of this research,
you can request a copy directly from the authors.
Pre and Post-Doctoral Education on Cone Beam CT
Abstract
Objectives
As the use of cone beam computed tomography (CBCT) in dentistry continues to grow, questions related to appropriate radiation safety, training, and interpretation arise. Recognizing this need, the American Dental Association published an advisory statement for the safe use of CBCT in dentistry and recommended that guidelines for appropriate training be established. The purpose of this study was to assess radiation safety concerns related to CBCT and identify voids in current education on CBCT for the predoctoral dental curriculum and continuing dental education.
Methods
A survey was mailed to general practitioners, oral surgeons, and periodontists in the Georgia Dental Association (n = 415).
Results
One hundred twenty-one surveys were received for a response rate of 29%. Sixty-eight percent of practitioners reported using CBCT, with 89% having used it for over 2 years. Few (12.4%) had experience with CBCT in dental school. Interest in continuing dental education on CBCT was reported at 59.8% and 43.6% for current users and nonusers of CBCT, respectively. Approximately 50% reported using precautionary radiation safety measures, and the methods used were varied.
Conclusions
Although a higher survey return rate would allow for stronger evidence, this project identified some areas of education voids including radiation safety and the factors that contribute to patient dose; CBCT basics including instruction on the limitations of CBCT; CBCT anatomy and pathology with additional time dedicated to the paranasal sinuses; and interpretation.
... However, none has directly compared the preferences and responses of general dentists and endodontists, where usage and training may differ, and none has compared preferences of endodontists across different geographic regions. Additionally, clinicians' education sources and knowledge levels have rarely been surveyed (Buchanan et al., 2017;Rabiee et al., 2018;Rai et al., 2018;Reddy et al., 2013), and the potential gap between training and clinical implementation does not appear to have been investigated in an area where the evidence is still being established. This information would allow comparison with current evidence and evidence-based guidelines, to provide educators with information to plan future coverage of the topic in primary dental degree programs, continuing professional education (CPE) and specialization programs. ...
... In this study, CPE provided by dental associations/societies was most highly attended (43.1%) followed by those from universities and commercial companies. These results are similar to surveys conducted in Georgia, USA (Buchanan et al., 2017) and Lithuania (Masyte et al., 2021) where courses run by professional or independent organizations were most commonly attended (46%, 45.1% respectively). In the Georgia study, 40% attended courses run by manufacturers, including 22% who only had training from manufacturers (Buchanan et al., 2017). ...
... These results are similar to surveys conducted in Georgia, USA (Buchanan et al., 2017) and Lithuania (Masyte et al., 2021) where courses run by professional or independent organizations were most commonly attended (46%, 45.1% respectively). In the Georgia study, 40% attended courses run by manufacturers, including 22% who only had training from manufacturers (Buchanan et al., 2017). Comparatively, a much smaller proportion of 2.6% in this study had received CPE only from commercial companies. ...
Aim
This study investigated the adoption of cone‐beam computed tomography (CBCT) by dentists and endodontists around the world, including their preferences in endodontic CBCT usage.
Methodology
An online questionnaire surveyed dental association members in Australia and New Zealand, and endodontic association members in Australia, Britain, Canada, Italy, New Zealand and the USA, about their CBCT training history, considerations in acquisition/interpretation, access to and usage of CBCT, preferred scan interpreter, and preferred endodontic scan settings. Data were analysed with Chi‐squared, independent sample t ‐tests, Cochran's Q and McNemar's tests.
Results
Responses from 578 endodontic specialists or postgraduates (Group E) and 185 non‐endodontic dentists (Group NE) were included. Continuing professional education (CPE) was the most common source of CBCT training (69.2%). Factors considered in CBCT acquisition/interpretation included beam hardening (75.4%), radiation exposure (61.1%) and patient movement (58.3%). Group E reported higher CBCT usage (90.8%) than Group NE (45.4%, p < .001) and greater workplace access to CBCT (81.1% vs. 25.9%, p < .001). Scans were interpreted by the respondent in most workplace scans (83.3%) and externally taken scans (60.5%); Group E were significantly more likely to interpret themselves than Group NE. Small field of view (83.6%) and high resolution (86.6%) were most preferred as settings for endodontic CBCTs; Group NE were less likely to choose these settings. There were some geographic variations within Group E.
Conclusions
CBCT training was most commonly acquired via CPE. Endodontic respondents reported very high CBCT usage and access in the workplace. There are educational implications regarding CBCT limitations, appropriate applications and interpretation.
... However, none has directly compared the preferences and responses of general dentists and endodontists, where usage and training may differ, and none has compared preferences of endodontists across different geographic regions. Additionally, clinicians' education sources and knowledge levels have rarely been surveyed (Buchanan et al., 2017;Rabiee et al., 2018;Rai et al., 2018;Reddy et al., 2013), and the potential gap between training and clinical implementation does not appear to have been investigated in an area where the evidence is still being established. This information would allow comparison with current evidence and evidence-based guidelines, to provide educators with information to plan future coverage of the topic in primary dental degree programs, continuing professional education (CPE) and specialization programs. ...
... In this study, CPE provided by dental associations/societies was most highly attended (43.1%) followed by those from universities and commercial companies. These results are similar to surveys conducted in Georgia, USA (Buchanan et al., 2017) and Lithuania (Masyte et al., 2021) where courses run by professional or independent organizations were most commonly attended (46%, 45.1% respectively). In the Georgia study, 40% attended courses run by manufacturers, including 22% who only had training from manufacturers (Buchanan et al., 2017). ...
... These results are similar to surveys conducted in Georgia, USA (Buchanan et al., 2017) and Lithuania (Masyte et al., 2021) where courses run by professional or independent organizations were most commonly attended (46%, 45.1% respectively). In the Georgia study, 40% attended courses run by manufacturers, including 22% who only had training from manufacturers (Buchanan et al., 2017). Comparatively, a much smaller proportion of 2.6% in this study had received CPE only from commercial companies. ...
Aim:
To investigate current endodontic practices, adoption of technologies and continuing education attendance within specialist endodontic practice globally and to identify geographic trends.
Methodology:
A web-based survey of endodontic association members in Australia, Britain, Canada, Italy, New Zealand and the USA on routine treatment preferences, armamentarium and education attendance was conducted. Chi-squared, independent sample t-tests, Cochran's Q test and McNemar's test were performed.
Results:
The survey was completed by 543 endodontists or endodontic post-graduate students. Almost all respondents used the dental operating microscope (DOM, 91.3%), engine-driven nickel-titanium instruments (NiTi, 97.6%), electronic apex locators (EAL, 93.0%), cone-beam computed tomography (CBCT, 91.2%) and calcium silicate-based materials (CSBMs, 93.7%). Dental dam was always used by 99.1%. Over half used irrigation adjuncts (81.8%), warm vertical compaction (74.6%) and heat-treated NiTi (60.2%). Geographic comparison between AP (Asia-Pacific, n = 78), AM (Americas, n = 402) and EM (Europe and Middle East, n = 63) was performed. AM and EM preferred single-visit treatment more (p < .001) and used higher sodium hypochlorite concentrations than AP. AM had more access to CBCT in the workplace (86.6%) than AP (65.4%, p < .001) and used CBCT for routine preoperative assessment (39.6%) more than EM (7.3%, p < .001). Almost all of EM used irrigation adjuncts (95.2%), more than AM (78.1%, p = .001). AP used steroid/antibiotic medicaments most (p < .001) and had the highest attendance at continuing education programmes.
Conclusion:
Several endodontic-specific armamentaria have reached almost complete adoption within global specialist endodontic practice, whilst the continued uptake of newer technologies should be followed over time. Some practising philosophies varied significantly across different geographic regions.
... 4 The necessity for standardisation of CBCT training, more comprehensive university-based training during predoctoral years, and more stringent registration procedures with continuing educational requirements has been raised. 3,[16][17][18][19][20] The rapid growth of CBCT in the dental field has been repeatedly reported across the globe. In Australia, a study examining the number of Medicare rebated CBCT and PR services found that the rate of CBCT scans per 100,000 population had increased by 42.3% between 2011 and 2014. ...
... Additionally, this growth may reflect the larger number of general dentists who are placing dental implants and undertaking orthodontic treatment, both of which frequently utilise CBCT data for treatment planning. 21 Given that implants have been reported as the leading indication for CBCT acquisition, 17,20,27,28 there may be some weight to this theory, which could be investigated in the future. ...
... 4,28,30,31 No advances in the teaching of implant software was noted in our study, despite implant dentistry being found to be the most common indication for CBCT scans. 17,20,27,28 These findings imply that the CBCT educational experience in Australia is not growing proportionally with the adoption of the machines. This may relate to the steep learning curve required by educators to obtain and integrate CBCT knowledge into both the theoretical and practical components of teaching. ...
Objectives
This is a follow-up study to assess growth in the number of cone beam computed tomography (CBCT) and panoramic radiography (PR) machines in Australia. It is also the first study to evaluate the current status of both CBCT and PR education in Australia.
Methods
CBCT and PR machine numbers were obtained from the radiation regulators across Australia. Australian dental schools were surveyed via email. The number of machines relative to population size and the number of dentists were calculated.
Results
In 2020, there were 706 CBCT machines and 3,059 PR machines, representing a 204.3% increase in the number of CBCT machines and an 82.0% increase in the number of PR machines over six years. Majority of Australian dental schools owned PR and CBCT machines. Most taught PR acquisition and interpretation, however only one-third taught CBCT image acquisition and interpretation to predoctoral students.
Conclusions
CBCT machine numbers increased by nearly three-fold while PR machines only increased by 1.6 times over a six-year period relative to population size and number of dentists. Only very few Australian dental schools provide CBCT education to predoctoral students, raising concern as to whether graduates are adequately trained upon program completion.
... Therefore, CBCT has been promoted as a superior option for the preoperative assessment of complex MTM extractions [6]. However, the increased accuracy of CBCT is a consequence of an increased workload and required level of professionalism; additionally, few dentists have undergone formal training in craniomaxillofacial imaging diagnosis, heightening the risk of misdiagnosis [8]. Moreover, in the layered 2-D image produced using CBCT, the potential proximity relationship between the IAN and the MTM may be miscalculated due to a lack of spatial information, as shown in Figure S1. ...
Objectives
During mandibular third molar (MTM) extraction surgery, preoperative analysis to quantify the proximity of the MTM to the surrounding inferior alveolar nerve (IAN) is essential to minimize the risk of IAN injury. This study aims to propose an automated tool to quantitatively measure the proximity of IAN and MTM in cone-beam computed tomography (CBCT) images.
Materials and methods
Using the dataset including 302 CBCT scans with 546 MTMs, a deep-learning-based network was developed to support the automatic detection of the IAN, MTM, and intersection region IR. To ensure accurate proximity detection, a distance detection algorithm and a volume measurement algorithm were also developed.
Results
The deep learning-based model showed encouraging segmentation accuracy of the target structures (Dice similarity coefficient: 0.9531 ± 0.0145, IAN; 0.9832 ± 0.0055, MTM; 0.8336 ± 0.0746, IR). In addition, with the application of the developed algorithms, the distance between the IAN and MTM and the volume of the IR could be equivalently detected (90% confidence interval (CI): − 0.0345–0.0014 mm, distance; − 0.0155–0.0759 mm³, volume). The total time for the IAN, MTM, and IR segmentation was 2.96 ± 0.11 s, while the accurate manual segmentation required 39.01 ± 5.89 min.
Conclusions
This study presented a novel, fast, and accurate model for the detection and proximity quantification of the IAN and MTM on CBCT.
Clinical relevance.
This model illustrates that a deep learning network may assist surgeons in evaluating the risk of MTM extraction surgery by detecting the proximity of the IAN and MTM at a quantitative level that was previously unparalleled.
... Only a small proportion of dentists (12.4%) seem to have gained some experience with CBCT imaging during their undergraduate training, and a large percentage of dentists have not received adequate training in craniomaxillofacial imaging diagnosis after graduation. (Brown et al., 2014;Buchanan et al., 2017;Ganguly et al., 2014). Consequently, researchers have proposed the implementation of artificial intelligence (AI) as an assisting tool for the analysis and interpretation of CBCT datasets (Hung et al., 2020;Issa et al., 2022;Lee et al.,2015). ...
Objectives
To investigate the accuracy of artificial intelligence (AI)‐based segmentation of the mandibular canal, compared to the conventional manual tracing, implementing implant planning software.
Materials and methods
Localization of the mandibular canals was performed for 104 randomly selected patients. A localization was performed by three experienced clinicians in order to serve as control. Five tracings were performed: One from a clinician with a moderate experience with a manual tracing (I 1 ), followed by the implementation of an automatic refinement (I 2 ), one manual from a dental student (S 1 ), and one from the experienced clinician, followed by an automatic refinement (E). Subsequently, two fully automatic AI‐driven segmentations were performed (A 1 ,A 2 ). The accuracy between each method was measured using root mean square error calculation.
Results
The discrepancy among the models of the mandibular canals, between the experienced clinicians and each investigated method ranged from 0.21 to 7.65 mm with a mean of 3.5 mm RMS error. The analysis of each separate mandibular canal's section revealed that mean RMS error was higher in the posterior and anterior loop compared to the middle section. Regarding time efficiency, tracing by experienced users required more time compared to AI‐driven segmentation.
Conclusions
The experience of the clinician had a significant influence on the accuracy of mandibular canal's localization. An AI‐driven segmentation of the mandibular canal constitutes a time‐efficient and reliable procedure for pre‐operative implant planning. Nevertheless, AI‐based segmentation results should always be verified, as a subsequent manual refinement of the initial segmentation may be required to avoid clinical significant errors.
... It is time-consuming to view the images slice by slice. Moreover, only a small proportion of dentists (12.4%) had experience with CBCT imaging in dental school based on a survey conducted by Buchanan et al. [10]. And most dentists have not received professional training in craniomaxillofacial imaging diagnosis [11], which increases the risk of missed diagnosis and misdiagnosis. ...
Objectives
The objective of our study was to develop and validate a deep learning approach based on convolutional neural networks (CNNs) for automatic detection of the mandibular third molar (M3) and the mandibular canal (MC) and evaluation of the relationship between them on CBCT.Materials and methodsA dataset of 254 CBCT scans with annotations by radiologists was used for the training, the validation, and the test. The proposed approach consisted of two modules: (1) detection and pixel-wise segmentation of M3 and MC based on U-Nets; (2) M3-MC relation classification based on ResNet-34. The performances were evaluated with the test set. The classification performance of our approach was compared with two residents in oral and maxillofacial radiology.ResultsFor segmentation performance, the M3 had a mean Dice similarity coefficient (mDSC) of 0.9730 and a mean intersection over union (mIoU) of 0.9606; the MC had a mDSC of 0.9248 and a mIoU of 0.9003. The classification models achieved a mean sensitivity of 90.2%, a mean specificity of 95.0%, and a mean accuracy of 93.3%, which was on par with the residents.Conclusions
Our approach based on CNNs demonstrated an encouraging performance for the automatic detection and evaluation of the M3 and MC on CBCT.Clinical relevanceAn automated approach based on CNNs for detection and evaluation of M3 and MC on CBCT has been established, which can be utilized to improve diagnostic efficiency and facilitate the precision diagnosis and treatment of M3.
... 12 A recent survey found limited and variable practices around CBCT radiation minimization, suggesting a void in knowledge of radiation safety. 13 General dentists wanting to understand CBCT radiation dose risk would face great difficulty. Turning to manufacturer promotional literature, they would be unlikely to find any mention of radiation dose. ...
Accessible sources of clinical information have proliferated over the past decade. Although these new sources that contextualize information for practice are user friendly, there are questions about their accuracy because much of the material is not peer reviewed. On the other hand, traditional peer-reviewed material can be somewhat removed from the needs of practicing dentists, and recently questions have been raised about the accuracy of journals. This study assessed the accuracy of cone beam computed tomography (CBCT) radiation safety information in both professional media and peer-reviewed journals. Articles introducing CBCT technology to dentists and published in peer-reviewed journals were compared to articles appearing in professional magazines, clinically oriented news sites, and blogs written by clinicians for clinicians. The reported radiation doses of CBCT and conventional dental radiographs were recorded, as were conclusions about the comparative doses of these 2 imaging modalities. The proportion of articles reporting CBCT dose to be greater than, equal to, or less than that of conventional dental radiographs was not different between the peer-reviewed and professional media articles during the period 2003-2016. There is weak evidence that the conclusions of peer-reviewed journal articles, but not professional media sources, became more conservative after the 2010 publication of an article in The New York Times that was critical of misinformation concerning the safety and efficacy of CBCT in dentistry. Professional media articles that were not peer reviewed were as accurate as peer-reviewed journals for this topic and during the time period assessed. However, the method used here necessitated a narrow focus, and more studies are needed to broaden understanding.
Objectives
The purpose of this study was to compare student learning of cone beam computed tomography (CBCT) interpretation using immersive virtual reality (VR) and three‐dimensional multiplanar (MP) reconstructions.
Methods
Sixty first‐year dental students were randomly allocated to two groups, VR and MP, and underwent a one‐on‐one educational intervention to identify anatomic structures using CBCT data. All participants completed three multiple‐choice questionnaires (MCQs) before (T1), immediately after (T2), and 2 weeks following (T3) the intervention. Additionally, pre‐survey, post‐survey, NASA Task Load Index (NASA‐TLX), and presence questionnaires were completed. Analysis of objective measures of performance on MCQs and subjective data from the questionnaires was completed (α = 0.05).
Results
There was a significant increase in test performance and informational recall between T1–T2 and T1–T3 for VR and MP groups ( p < 0.001). However, there were no significant differences in performance on MCQs between T2 and T3. Analysis of the Presence questionnaire indicated that the VR group felt decreased distraction ( p = 0.013), increased realism ( p = 0.035), and increased involvement ( p = 0.047) during the educational intervention when compared with the MP group. Analysis of the NASA‐TLX indicated that the VR group experienced more physical demand ( p < 0.01) but similar cognitive demand when compared with the MP group. Qualitative responses indicated that the VR group had a more dynamic sense of visualization and manipulation compared to the MP group.
Conclusion
Results from this study show that VR is as effective as traditional MP methods of CBCT interpretation learning. Further benefits of VR educational intervention include increased involvement, realism and less distraction.
Objectives:
The purpose of this study was to evaluate the efficacy of student learning of anatomy and 3D imaging concepts using cone beam computed tomography (CBCT) and immersive virtual reality (VR) technology.
Methodology:
Ninety (n = 90) first year dental students with no previous experience in 3D imaging were recruited. All participants completed a 10-item, multiple-choice questionnaire (MCQ) and a pre-survey prior to the educational intervention. Following a brief video orientation on CBCT and anatomy, each participant underwent a one-on-one educational intervention using immersive VR with calibrated instructors to identify head and neck anatomic structures using a VR/CBCT educational tool. Immediately following the intervention, all participants completed a postsurvey, a second MCQ, NASA task load index and presence questionnaires. Participants completed a third MCQ 2 weeks following the intervention. Analysis of objective measures of performance on MCQ's (p < 0.05) and subjective data from the questionnaires was completed.
Results:
The students doubled their mean test scores 2.45 ± 1.274 to 5.99 ± 1.576 on MCQ's immediately following the educational intervention (p < 0.05). The significant increase in the MCQ test scores was maintained after 2 weeks, 5.73 ± 1.721 (p < 0.05). There were no gender differences in student test performance. Students rated the immersive VR/CBCT educational intervention experience highly for control, sensory, and realism factors with minimal distraction and frustration factors.
Conclusion:
Results from this study show that immersive VR/CBCT educational intervention improved test performance and contributed to information recall in students. Further benefits reported by participants include the sense of presence and increased engagement using immersive VR.
Backgrounds
Canalis sinuosus (CS) is a neurovascular canal that corresponds to a small branch of the infraorbital canal.
Objective
This study aimed at assessing the knowledge and detection performance of CS among dentists and dental students.
Methods
Four-hundred and five dentists and dental students answered a questionnaire with three parts: 1. Socio-demographic; 2. Clinical cases with cone- beam computed tomography (CBCT) sections showing CS, and 3. Previous knowledge about CS. Chi-square test and Spearman’s correlation test were used to compare results as appropriate. P-values below 0.05 were considered statistically significant.
Results
Most participants did not identify CS in any CBCT. There was association between the number of correct answers and dental specialties. Most individuals had not learned about CS previously. There was association between past knowledge of CS and gender, highest academic degree, working environment, dental specialty, and number of correct answers but not with age or experience in dentistry.
Conclusions
This study suggests that most dentists are not aware about CS and do not know how to diagnose it. Previous knowledge about CS positively influenced its identification in CBCT.
E‐learning is an educational method that improves knowledge innovation by sharing relevant images for advanced learning, especially in a pandemic state. Furthermore, cone‐beam computed tomography (CBCT) is a method that gathers medical or dental diagnostic images. This study aimed to analyze the effectiveness of dental anatomy education through a CBCT technology tool, through teachers' and students' perspectives, adjusted according to the disruptions caused by the Covid‐19 pandemic. A cohort study and longitudinal exploratory analysis were performed. Forty undergraduate first‐year dental students, from the University of Coimbra in Portugal, were selected as per the inclusion and exclusion criteria. Two different teaching methods were applied during an identical time‐period: face‐to‐face lectures complemented by physical models (T1 cohort) and webinar lectures complemented by CBCT images (T2 cohort). Learning outcomes were then studied according to theoretical and spatial orientation contexts. A self‐reported survey that focused on students' satisfaction, stress, and support was studied. Both teaching methods were analyzed with paired sample student's t‐test and Pearson Correlation Confidence intervals 95% with P < 0.05. Furthermore, exploratory factor analysis (EFA) was used for self‐reported satisfaction survey validity and reliability analysis. The learning outcomes between T1 and T2 cohorts were statistically significant, (P < 0.001) corresponding to differences with a large effect degree (r > 0.60). Students' satisfaction, as measured on a six‐point Likert scale, was positively influenced by the webinar lectures supplemented with CBCT images (T2 cohort) in a learning context (4.95 ± 0.5) and future applications (5.92 ± 0.27). In conclusion, the webinar approach with CBCT images was more effective and better learning method for teaching dental anatomy.
Objectives
To develop and evaluate an educational web‐based program for temporomandibular joint (TMJ) assessment using cone‐beam computed tomography (CBCT).
Methods
A web‐based educational program was designed for TMJ assessment using CBCT images. Fifteen CBCT cases of the TMJ (three‐dimensional reconstructed volumes) and an assessment module based on image analysis criteria in the Diagnostic Criteria for Temporomandibular Disorders (DC/TMD) were added to the program. Thirty‐six undergraduate dental students were invited to test the program by assessing all cases twice: before and after 2 months of training. Participants submitted written subjective evaluations of the program.
Results
The web‐based program can be accessed on Malmö University webpage (www.cbct-tmj.mau.se). Despite limited CBCT learning in their undergraduate training and not using the program in the 2‐month interval, the students were able to correctly diagnose 80% of the cases at the second assessment. Their diagnoses, however, did not differ significantly from the first assessment. Overall, the students were satisfied with the program and considered it user friendly.
Conclusion
The web‐based educational program that was developed in the present study and tested by dental students could be a useful educational tool for TMJ assessment using CBCT.
The use of cone beam CT (CBCT) is common among dentists and dental specialists in North America and the world. The regions of interest captured by these machines vary in size and applications are numerous. If using the image data from this modality, clinicians are obligated to examine the entire volume and to understand and recognize all the anatomy in the head and neck region that can be portrayed and any abnormalities detected in otherwise normal surroundings. This article attempts to identify common entities found in the anatomic regions captured in a CBCT volume and those common abnormalities that must be referred.
Cone Beam Computed Tomography (CBCT) is a diagnostic imaging modality that provides high-quality, accurate three-dimensional (3D) representations of the osseous elements of the maxillofacial skeleton. CBCT systems are available that provide small field of view images at low dose with sufficient spatial resolution for applications in endodontic diagnosis, treatment guidance, and posttreatment evaluation. This article provides a literature review and pictorial demonstration of CBCT as an imaging adjunct for endodontics.
The objective of this paper is to present a new type of volumetric CT which uses the cone-beam technique instead of traditional fan-beam technique. The machine is dedicated to the dento-maxillo-facial imaging, particularly for planning in the field of implantology. The main characteristics of the unit are presented with reference to the technical parameters as well as the software performance. Images obtained are reported as various 2D sections of a volume reconstruction. Also, measurements of the geometric accuracy and the radiation dose absorbed by the patient are obtained using specific phantoms. Absorbed dose is compared with that given off by spiral CT. Geometric accuracy, evaluated with reference to various reconstruction modalities and different spatial orientations, is 0.8-1% for width measurements and 2.2% for height measurements. Radiation dose absorbed during the scan shows different profiles in central and peripheral axes. As regards the maximum value of the central profile, dose from the new unit is approximately one sixth that of traditional spiral CT. The new system appears to be very promising in dentomaxillo-facial imaging and, due to the good ratio between performance and low cost, together with low radiation dose, very interesting in view of large-scale use of the CT technique in such diagnostic applications.
Purpose:
The purpose of the present study was to determine the frequency of relevant nondental related incidental findings in cone-beam computed tomography (CBCT) of the head and neck.
Material and methods:
Nine hundred ninety-nine images were retrospectively reviewed for incidental findings. Those were defined as carotid artery calcification (CAC), paranasal sinus findings (PSF), sialolithiasis of the parotid gland (SP) or submandibular gland (SSub), calcification of the ligamentum stylohyoideum (CLS), and Stafne bone cavity (SBC). All datasets obtained between 2010 and 2014 at a university-based school of dental medicine in Switzerland were reviewed. Demographic data such as age and sex were also recorded.
Results:
A total of 350 incidental findings within the 999 CBCT scans were identified. The most frequent finding was PSF (56.2%), followed by CLS (23.1%), CAC (10.7%), and SSub (1.6%). No SP or SBC was found. Incidental findings were most frequent between 61 and 70 years of age. Males had a higher prevalence in CAC, PSF, and SSub than females.
Conclusions:
These results underscore the need for a complete examination of every CBCT image beyond the region of interest.
The increasing use of cone-beam computed tomography in orthodontics has been coupled with heightened concern about the long-term risks of x-ray exposure in orthodontic populations. An industry response to this has been to offer low-exposure alternative scanning options in newer cone-beam computed tomography models.
Effective doses resulting from various combinations of field of view size and field location comparing child and adult anthropomorphic phantoms with the recently introduced i-CAT FLX cone-beam computed tomography unit (Imaging Sciences, Hatfield, Pa) were measured with optical stimulated dosimetry using previously validated protocols. Scan protocols included high resolution (360° rotation, 600 image frames, 120 kV[p], 5 mA, 7.4 seconds), standard (360°, 300 frames, 120 kV[p], 5 mA, 3.7 seconds), QuickScan (180°, 160 frames, 120 kV[p], 5 mA, 2 seconds), and QuickScan+ (180°, 160 frames, 90 kV[p], 3 mA, 2 seconds). Contrast-to-noise ratio was calculated as a quantitative measure of image quality for the various exposure options using the QUART DVT phantom.
Child phantom doses were on average 36% greater than adult phantom doses. QuickScan+ protocols resulted in significantly lower doses than standard protocols for the child (P = 0.0167) and adult (P = 0.0055) phantoms. The 13 × 16-cm cephalometric fields of view ranged from 11 to 85 μSv in the adult phantom and 18 to 120 μSv in the child phantom for the QuickScan+ and standard protocols, respectively. The contrast-to-noise ratio was reduced by approximately two thirds when comparing QuickScan+ with standard exposure parameters.
QuickScan+ effective doses are comparable with conventional panoramic examinations. Significant dose reductions are accompanied by significant reductions in image quality. However, this trade-off might be acceptable for certain diagnostic tasks such as interim assessment of treatment results.
Background:
The authors analyzed the literature critically to determine the frequency and nature of incidental findings (IFs) in cone-beam computed tomographic (CBCT) scans of the head and neck region.
Types of studies reviewed:
The authors conducted a systematic search of several electronic databases (MEDLINE, Embase, PubMed, Scopus, Web of Science, the Cochrane Library) through July 14, 2012, as well as a limited gray-literature search (in Google Scholar). Inclusion criteria encompassed the frequency of reports of IFs in the head and neck region in CBCT imaging, regardless of the sample origin. The authors used no search limitations. They evaluated methodological quality according to 15 criteria related to study design, population characteristics and statistical analysis.
Results:
Initially, the authors identified 66 articles from the electronic database searches and another one via the gray-literature search. Once they applied the final selection criteria, they found that only five articles satisfied the inclusion criteria. In articles in which investigators reported the number of IFs as the absolute number of IFs detected, the frequency ranged from 1.3 to 2.9 IFs per CBCT scan. Conversely, in articles in which authors reported the number of IFs as the number of scans containing IFs, the frequency ranged from 24.6 to 93.4 percent of CBCT scans. Methodological quality averaged 77.2 percent (range, 60-93 percent) of the maximum possible score.
Conclusions and clinical implications:
IFs are detected relatively frequently in CBCT imaging, and considerable variation is evident in their frequency and nature. The majority are extragnathic findings (that is, those found outside the region of the dentition and alveolus), thus emphasizing the need for complete and proper review of the entire image, regardless of field of view or region of interest.
The International Congress of Oral Implantologists has supported the development of this consensus report involving the use of Cone Beam Computed Tomography (CBCT) in implant dentistry with the intent of providing scientifically based guidance to clinicians regarding its use as an adjunct to traditional imaging modalities.
The literature regarding CBCT and implant dentistry was systematically reviewed. A PubMed search that included studies published between January 1, 2000, and July 31, 2011, was conducted. Oral presentations, in conjunction with these studies, were given by Dr. Erika Benavides, Dr. Scott Ganz, Dr. James Mah, Dr. Myung-Jin Kim, and Dr. David Hatcher at a meeting of the International Congress of Oral Implantologists in Seoul, Korea, on October 6-8, 2011.
The studies published could be divided into four main groups: diagnostics, implant planning, surgical guidance, and postimplant evaluation.
The literature supports the use of CBCT in dental implant treatment planning particularly in regards to linear measurements, three-dimensional evaluation of alveolar ridge topography, proximity to vital anatomical structures, and fabrication of surgical guides. Areas such as CBCT-derived bone density measurements, CBCT-aided surgical navigation, and postimplant CBCT artifacts need further research. ICOI RECOMMENDATIONS: All CBCT examinations, as all other radiographic examinations, must be justified on an individualized needs basis. The benefits to the patient for each CBCT scan must outweigh the potential risks. CBCT scans should not be taken without initially obtaining thorough medical and dental histories and performing a comprehensive clinical examination. CBCT should be considered as an imaging alternative in cases where the projected implant receptor or bone augmentation site(s) are suspect, and conventional radiography may not be able to assess the true regional three-dimensional anatomical presentation. The smallest possible field of view should be used, and the entire image volume should be interpreted.
The aim of this article was to describe our experience in the field of preoperative ear, nose and throat (ENT) assessment in each candidate for (maxillary) sinus floor elevation (SFE) after the introduction of a systematic protocol. The protocol evaluates the sinus compliance by means of ENT preliminary examination with nasal fiberoptic endoscopy to identify all of the situations that may predispose to post-lifting complications, i.e. potentially irreversible (PIECs) and presumably reversible (PRECs) ENT contraindications to SFE, and to evaluate its impact on SFE success.
Patient candidates for SFE were carefully assessed by means of case-history collection, complete ENT evaluation with nasal fiberoptic endoscopy and imaging to detect PIECs, PRECs, or no ENT contraindications for SFE. In case of PRECs, SFE was postponed until complete clinical recovery. Impact of preoperative ENT assessment on SFE outcome was assessed by means of post-lifting telephonic interview and ENT evaluation.
PRECs were detected and resolved before SFE was performed in 38.2% of our 34 patients; no intra- or post-lifting complications occurred in the patients with no ENT contraindications or PRECs.
The results of the study suggest that a careful multi-tasking preoperative management, including an ENT assessment with fiberoptic endoscopy and a radiological evaluation extended to the ostio-meatal complex, is very useful in candidates for SFE.
Dental implant surgery in the posterior maxilla often involves the maxillary sinuses. Sinus surgery for dental implants is highly successful, but the preoperative risk is difficult to assess because a routine preoperative evaluation does not include an intranasal examination by an otolaryngologist. The purpose of the present study is to obtain the opinions of ear, nose, and throat (ENT) specialists located within New York state in an effort to establish a referral protocol before performing a maxillary sinus elevation. This study assesses the need to consult an ENT specialist for evaluation and treatment recommendations in the pretreatment workup.
A questionnaire and a stamped, return envelope with an identification number was mailed to 302 physicians who maintained a current ENT-specialty practice or practiced that specialty in a hospital or clinic setting in New York state. The requirement criteria included a valid address and specialty designation. Up to two follow-up phone calls were made, and another questionnaire was mailed 30 days after the initial mailing. The questionnaire included eight computerized tomography (CT)?scan images that represented different sinus configurations. Answers to the five questions were statistically evaluated and analyzed. A total of 63 recipients returned the questionnaire and were included in the study.
A majority of 58.7% (95% confidence interval: 46.9% to 71.1%) of respondents recommended that a maxillary sinus CT scan should be routinely prescribed before a sinus-lift surgery. Patient symptoms that ENT specialists suggested indicated referral included nose complications/problems (40.1%) and sinus issues (23.6%). Of the eight CT-scan images, referral suggestions were >50% for the following: an occluded sinus with septum, inflammation at the base of the sinus only, a sinus with a generalized thickened membrane, an oroantral fistula, a thickened sinus membrane in association with teeth that had endodontic and/or periodontic involvement, and a nearly completely occluded sinus that was missing palatal bone. For patients with seasonal allergies, ENT specialists suggested delaying surgery (20.6%) or controlling symptoms before surgery (41.3%). Concerns included a past history of a sinus surgery (87.3%), chronic sinusitis (85.7%), presence of ostium stenosis (68.3%), nasal or sinus obstruction (82.5%), and oroantral fistulation (74.6%).
Within the limits of the study, an attempt is made to develop a preoperative protocol, and 63 responses from ENT specialists suggested that the majority (58.7%) would recommend a maxillary CT scan before a sinus-lift surgery. Their greatest concerns were a prior sinus surgery, severe sinus inflammation, nasal/sinus obstruction, and oroantral fistulation.
To describe a compact computed tomographic apparatus (Ortho-CT) for use in dental practice.
Ortho-CT is a cone-beam-type of CT apparatus consisting of a multifunctional maxillofacial imaging machine (Scanora, Soredex, Helsinki, Finland) in which the film is replaced with an X-ray imaging intensifier (Hamamatsu Photonics, Hamamatsu, Japan). The region of image reconstruction is a cylinder 32 mm in height and 38 mm in diameter and the voxel is a 0.136-mm cube. Scanning is at 85 kV and 10 mA with a 1 mm Cu filter. The scan time is 17 s comparable with that required for rotational panoramic radiography. A single scan collects 512 sets of projection data through 360 degrees and the image is reconstructed by a personal computer. The time required for image reconstruction is about 10 min.
The resolution limit was about 2.0 lp mm-1 and the skin entrance dose 0.62 mGy. Excellent image quality was obtained with a tissue-equivalent skull phantom: roots, periodontal ligament space, lamina dura, and cancellous bone were clearly visualized.
Ortho-CT provides three-dimensional images of excellent quality for dental use at a low entrance dose.
We sought to compare a new limited cone beam computed tomography (CT) machine for dental use (3DX) with the multidetector CT machine for image quality and skin doses.
Images of the right maxillary central incisor and the left mandibular first molar of an anthropomorphic phantom were taken by both the 3DX and the multidetector CT. A 5-point method was used to evaluate the depiction of cortical and cancellous bone, enamel, dentin, pulp cavity, periodontal ligament space, lamina dura, and overall impressions. Furthermore, the skin doses for both modalities were compared.
The image quality of the 3DX was better than the multidetector CT for all items (P < .01). Moreover, the mean skin doses with the multidetector CT were 458 mSv per examination, whereas the doses with the 3DX were 1.19 mSv per examination.
These results clearly indicate the superiority of the 3DX in the display of hard tissues in the dental area while substantially decreasing the dose to the patient.
Dentistry continues to “go digital.” Use of digital radiography has increased in private practice, particularly with endodontists. Computed Tomography (CT) is routinely performed for dental implant imaging, and many dental schools are moving toward a paperless and filmless environment. As this trend continues, a question is “What are we trying to achieve?” Is it just a fast way to get an image? A method to reduce patient record storage? Save the environment from processing chemicals? Reduce remakes by digitally adjusting contrast and brightness? Or, is there a greater possibility?
The purpose of this paper is to present the system configuration and physical properties of a new dentomaxillofacial X-ray cone beam CT system (CB MercuRay) being developed.
The system consists of an image intensifier and a cone beam X-ray source. There are two different models of this system, each with a different size image intensifier, 9" or 12". Each system has three field of view (FOV) modes. The 12" system has facial (F), panoramic (P) and implant (I) FOV modes. The 9" system has P, I and dental (D) modes. Images produced by these systems consist of 512 x 512 x 512 isotropic voxels. Physical properties such as resolution, noise and distortion of the images were evaluated in this study. Modulation transfer function (MTF) was measured using Boone's method. Image noise was measured as the standard deviation of the CT value in water. Circularity of the axial images yielded by the two models was measured using an 8 mm diameter acrylic pipe phantom.
The resolving power at a MTF of 0.1 in the D mode was over 2.0 lp mm(-1), suggesting that this system yields images of high resolution. The standard deviation of the CT value in water was approximately 80, which is thought to be greater than that of conventional CT. The circularity of images of the pipe phantom was 99% of the ideal value.
This study shows that our newly developed cone beam CT system produces high resolution three-dimensional volumetric images that will be useful for the examination of dentomaxillofacial disorders.