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Koivisto J, Wolff J, Pauwels R, Kaasalainen T, Suomalainen A, Stoor P, Horelli J, Suojanen J. Assessment of cone-beam CT technical image quality indicators and radiation dose for optimal STL model used in visual surgical planning. Dentomaxillofac Radiol 2024; 53:423-433. [PMID: 38913866 PMCID: PMC11358642 DOI: 10.1093/dmfr/twae026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2024] [Revised: 04/15/2024] [Accepted: 06/12/2024] [Indexed: 06/26/2024] Open
Abstract
OBJECTIVES The aim of this study was to identify cone-beam computed tomography (CBCT) protocols that offer an optimal balance between effective dose (ED) and 3D model for orthognathic virtual surgery planning, using CT as a reference, and to assess whether such protocols can be defined based on technical image quality metrics. METHODS Eleven CBCT (VISO G7, Planmeca Oy, Helsinki, Finland) scan protocols were selected out of 32 candidate protocols, based on ED and technical image quality measurements. Next, an anthropomorphic RANDO SK150 phantom was scanned using these 11 CBCT protocols and 2 CT scanners for bone quantity assessments. The resulting DICOM (Digital Imaging and Communications in Medicine) files were converted into Standard Tessellation Language (STL) models that were used for bone volume and area measurements in the predefined orbital region to assess the validity of each CBCT protocol for virtual surgical planning. RESULTS The highest CBCT bone volume and area of the STL models were obtained using normal dose protocol (F2) and ultra-low dose protocol (J13), which resulted in 48% and 96% of the mean STL bone volume and 48% and 95% of the bone area measured on CT scanners, respectively. CONCLUSIONS The normal dose CBCT protocol "F2" offered optimal bone area and volume balance for STL. The optimal CBCT protocol can be defined using contrast-to-noise ratio and modulation transfer function values that were similar to those of the reference CT scanners'. CBCT scanners with selected protocols can offer a viable alternative to CT scanners for acquiring STL models for virtual surgical planning at a lower effective dose.
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Affiliation(s)
- Juha Koivisto
- Department of Physics, University of Helsinki, 00560 Helsinki, Finland
| | - Jan Wolff
- Department of Dentistry and Oral Health, Section of Oral and Maxillofacial Surgery and Oral Pathology, Aarhus University, DK-8000 Aarhus C, Denmark
| | - Ruben Pauwels
- Department of Dentistry and Oral Health, Aarhus University, DK-8000 Aarhus C, Denmark
| | - Touko Kaasalainen
- HUS Diagnostic Center, Radiology, University of Helsinki, Helsinki, P.O. BOX 224, FI-00029, Finland
| | - Anni Suomalainen
- HUS Diagnostic Center, Radiology, University of Helsinki, Helsinki, P.O. BOX 224, FI-00029, Finland
- Helsinki University Hospital, Helsinki, P.O. Box 63 00014, Finland
| | - Patricia Stoor
- Helsinki University Hospital, Helsinki, P.O. Box 63 00014, Finland
- Department of Oral and Maxillofacial Diseases, Head and Neck Center, University of Helsinki, P.O. BOX 41, FI-00014, Finland
| | | | - Juho Suojanen
- Helsinki University Hospital, Helsinki, P.O. Box 63 00014, Finland
- Department of Oral and Maxillofacial Surgery, Päijät-Häme Joint Authority for Health and Wellbeing, Lahti, P.O. BOX 202, FIN-15101, Finland
- Cleft Palate and Craniofacial Centre, Department of Plastic Surgery, University of Helsinki, Helsinki, P.O. BOX 281 FI-00029, Finland
- Faculty of Medicine, Clinicum, University of Helsinki, P.O. BOX 63, FI-00014, Finland
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Alrashed S, Dutra V, Chu TMG, Yang CC, Lin WS. Influence of exposure protocol, voxel size, and artifact removal algorithm on the trueness of segmentation utilizing an artificial-intelligence-based system. J Prosthodont 2024; 33:574-583. [PMID: 38305665 DOI: 10.1111/jopr.13827] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2023] [Accepted: 01/09/2024] [Indexed: 02/03/2024] Open
Abstract
PURPOSE To evaluate the effects of exposure protocol, voxel sizes, and artifact removal algorithms on the trueness of segmentation in various mandible regions using an artificial intelligence (AI)-based system. MATERIALS AND METHODS Eleven dry human mandibles were scanned using a cone beam computed tomography (CBCT) scanner under differing exposure protocols (standard and ultra-low), voxel sizes (0.15 mm, 0.3 mm, and 0.45 mm), and with or without artifact removal algorithm. The resulting datasets were segmented using an AI-based system, exported as 3D models, and compared to reference files derived from a white-light laboratory scanner. Deviation measurement was performed using a computer-aided design (CAD) program and recorded as root mean square (RMS). The RMS values were used as a representation of the trueness of the AI-segmented 3D models. A 4-way ANOVA was used to assess the impact of voxel size, exposure protocol, artifact removal algorithm, and location on RMS values (α = 0.05). RESULTS Significant effects were found with voxel size (p < 0.001) and location (p < 0.001), but not with exposure protocol (p = 0.259) or artifact removal algorithm (p = 0.752). Standard exposure groups had significantly lower RMS values than the ultra-low exposure groups in the mandible body with 0.3 mm (p = 0.014) or 0.45 mm (p < 0.001) voxel sizes, the symphysis with a 0.45 mm voxel size (p = 0.011), and the whole mandible with a 0.45 mm voxel size (p = 0.001). Exposure protocol did not affect RMS values at teeth and alveolar bone (p = 0.544), mandible angles (p = 0.380), condyles (p = 0.114), and coronoids (p = 0.806) locations. CONCLUSION This study informs optimal exposure protocol and voxel size choices in CBCT imaging for true AI-based automatic segmentation with minimal radiation. The artifact removal algorithm did not influence the trueness of AI segmentation. When using an ultra-low exposure protocol to minimize patient radiation exposure in AI segmentations, a voxel size of 0.15 mm is recommended, while a voxel size of 0.45 mm should be avoided.
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Affiliation(s)
- Safa Alrashed
- Oral Biology PhD program in the College of Dentistry, Division of Restorative and Prosthetic Dentistry, The Ohio State University, Columbus, Ohio, USA
| | - Vinicius Dutra
- Department of Oral Pathology, Medicine, and Radiology, Indiana University School of Dentistry, Indianapolis, Indiana, USA
| | - Tien-Min G Chu
- Department of Biomedical Sciences and Comprehensive Care, Indiana University School of Dentistry, Indianapolis, Indiana, USA
| | - Chao-Chieh Yang
- Department of Prosthodontics, Indiana University School of Dentistry, Indianapolis, Indiana, USA
- Advanced Education Program in Prosthodontics, Department of Prosthodontics, Indiana University School of Dentistry, Indianapolis, Indiana, USA
| | - Wei-Shao Lin
- Department of Prosthodontics, Indiana University School of Dentistry, Indianapolis, Indiana, USA
- Advanced Education Program in Prosthodontics, Department of Prosthodontics, Indiana University School of Dentistry, Indianapolis, Indiana, USA
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Nogueira-Reis F, Morgan N, Nomidis S, Van Gerven A, Oliveira-Santos N, Jacobs R, Tabchoury CPM. Three-dimensional maxillary virtual patient creation by convolutional neural network-based segmentation on cone-beam computed tomography images. Clin Oral Investig 2023; 27:1133-1141. [PMID: 36114907 PMCID: PMC9985582 DOI: 10.1007/s00784-022-04708-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2022] [Accepted: 09/01/2022] [Indexed: 11/03/2022]
Abstract
OBJECTIVE To qualitatively and quantitatively assess integrated segmentation of three convolutional neural network (CNN) models for the creation of a maxillary virtual patient (MVP) from cone-beam computed tomography (CBCT) images. MATERIALS AND METHODS A dataset of 40 CBCT scans acquired with different scanning parameters was selected. Three previously validated individual CNN models were integrated to achieve a combined segmentation of maxillary complex, maxillary sinuses, and upper dentition. Two experts performed a qualitative assessment, scoring-integrated segmentations from 0 to 10 based on the number of required refinements. Furthermore, experts executed refinements, allowing performance comparison between integrated automated segmentation (AS) and refined segmentation (RS) models. Inter-observer consistency of the refinements and the time needed to create a full-resolution automatic segmentation were calculated. RESULTS From the dataset, 85% scored 7-10, and 15% were within 3-6. The average time required for automated segmentation was 1.7 min. Performance metrics indicated an excellent overlap between automatic and refined segmentation with a dice similarity coefficient (DSC) of 99.3%. High inter-observer consistency of refinements was observed, with a 95% Hausdorff distance (HD) of 0.045 mm. CONCLUSION The integrated CNN models proved to be fast, accurate, and consistent along with a strong interobserver consistency in creating the MVP. CLINICAL RELEVANCE The automated segmentation of these structures simultaneously could act as a valuable tool in clinical orthodontics, implant rehabilitation, and any oral or maxillofacial surgical procedures, where visualization of MVP and its relationship with surrounding structures is a necessity for reaching an accurate diagnosis and patient-specific treatment planning.
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Affiliation(s)
- Fernanda Nogueira-Reis
- Department of Oral Diagnosis, Division of Oral Radiology, Piracicaba Dental School, University of Campinas (UNICAMP), Av. Limeira 901, Piracicaba, São Paulo, 13414‑903, Brazil.,OMFS IMPATH Research Group, Department of Imaging & Pathology, Faculty of Medicine, KU Leuven & Oral and Maxillofacial Surgery, University Hospitals Leuven, Kapucijnenvoer 33, 3000, Leuven, Belgium
| | - Nermin Morgan
- OMFS IMPATH Research Group, Department of Imaging & Pathology, Faculty of Medicine, KU Leuven & Oral and Maxillofacial Surgery, University Hospitals Leuven, Kapucijnenvoer 33, 3000, Leuven, Belgium.,Department of Oral Medicine, Faculty of Dentistry, Mansoura University, Mansoura , 35516, Dakahlia, Egypt
| | | | | | - Nicolly Oliveira-Santos
- Department of Oral Diagnosis, Division of Oral Radiology, Piracicaba Dental School, University of Campinas (UNICAMP), Av. Limeira 901, Piracicaba, São Paulo, 13414‑903, Brazil.,OMFS IMPATH Research Group, Department of Imaging & Pathology, Faculty of Medicine, KU Leuven & Oral and Maxillofacial Surgery, University Hospitals Leuven, Kapucijnenvoer 33, 3000, Leuven, Belgium
| | - Reinhilde Jacobs
- OMFS IMPATH Research Group, Department of Imaging & Pathology, Faculty of Medicine, KU Leuven & Oral and Maxillofacial Surgery, University Hospitals Leuven, Kapucijnenvoer 33, 3000, Leuven, Belgium. .,Department of Dental Medicine, Karolinska Institutet, Box 4064, 141 04, Huddinge, Stockholm, Sweden.
| | - Cinthia Pereira Machado Tabchoury
- Department of Biosciences, Division of Biochemistry, Piracicaba Dental School, University of Campinas (UNICAMP), Av. Limeira 901, Piracicaba, São Paulo, 13414‑903, Brazil
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Manufacturing Polymer Model of Anatomical Structures with Increased Accuracy Using CAx and AM Systems for Planning Orthopedic Procedures. Polymers (Basel) 2022; 14:polym14112236. [PMID: 35683908 PMCID: PMC9182597 DOI: 10.3390/polym14112236] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Revised: 05/24/2022] [Accepted: 05/30/2022] [Indexed: 01/27/2023] Open
Abstract
Currently, medicine uses typical industrial structure techniques, including reverse engineering, data processing, 3D-CAD modeling, 3D printing, and coordinate measurement techniques. Taking this into account, one can notice the applications of procedures used in the aviation or automotive industries based on the structure of Industry 4.0 in the planning of operations and the production of medical models with high geometric accuracy. The procedure presented in the publication shortens the processing time of tomographic data and increases the reconstruction accuracy within the hip and knee joints. The procedure allows for the partial removal of metallic artifacts from the diagnostic image. Additionally, numerical models of anatomical structures, implants, and bone cement were developed in more detail by averaging the values of local segmentation thresholds. Before the model manufacturing process, additional tests of the PLA material were conducted in terms of its strength and thermal properties. Their goal was to select the appropriate type of PLA material for manufacturing models of anatomical structures. The numerical models were divided into parts before being manufactured using the Fused Filament Fabrication technique. The use of the modifier made it possible to change the density, type of filling, number of counters, and the type of supporting structure. These treatments allowed us to reduce costs and production time and increase the accuracy of the printout. The accuracy of the manufactured model geometry was verified using the MCA-II measuring arm with the MMDx100 laser head and surface roughness using a 3D Talyscan 150 profilometer. Using the procedure, a decrease in geometric deviations and amplitude parameters of the surface roughness were noticed. The models based on the presented approach allowed for detailed and meticulous treatment planning.
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Tayman MA, Kamburoğlu K, Ocak M, Özen D. Effect of different voxel sizes on the accuracy of CBCT measurements of trabecular bone microstructure: A comparative micro-CT study. Imaging Sci Dent 2022; 52:171-179. [PMID: 35799972 PMCID: PMC9226237 DOI: 10.5624/isd.20220025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2022] [Revised: 03/24/2022] [Accepted: 04/02/2022] [Indexed: 11/18/2022] Open
Affiliation(s)
- Mahmure Ayşe Tayman
- Department of Periodontology, Faculty of Dentistry, Ankara Yıldırım Beyazıt University, Ankara, Turkey
| | - Kıvanç Kamburoğlu
- Department of Dentomaxillofacial Radiology, Faculty of Dentistry, Ankara University, Ankara, Turkey
| | - Mert Ocak
- Department of Basic Medical Sciences-Anatomy, Faculty of Dentistry, Ankara University, Ankara, Turkey
| | - Doğukan Özen
- Department of Biostatistics, Faculty of Veterinary Medicine, Ankara University, Ankara, Turkey
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Bielecki-Kowalski B, Kozakiewicz M. Assessment of Differences in the Dimensions of Mandible Condyle Models in Fan- versus Cone-Beam Computer Tomography Acquisition. MATERIALS 2021; 14:ma14061388. [PMID: 33809298 PMCID: PMC7999192 DOI: 10.3390/ma14061388] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Revised: 03/04/2021] [Accepted: 03/08/2021] [Indexed: 11/16/2022]
Abstract
Modern treatment in the field of head and neck surgery aims for the least invasive therapy and places great emphasis on restorative treatment, especially in the case of injury and deformation corrective surgery. More and more often, surgeons use CAD/CAM (Computer-Aided Design and Computer-Aided Manufacturing) tools in their daily practice in the form of models, templates, and computer simulations of planning. These tools are based on DICOM (Digital Imaging and Communications in Medicine) files derived from computed tomography. They can be obtained from both fan-beam (FBCT) and cone-beam tomography (CBCT) acquisitions, which are subsequently segmented in order to transform them into a 1-bit 3D model, which is the basis for further CAD processes. AIM Evaluation of differences in the dimensions of mandible condyle models in fan- versus cone-beam computer tomography for surgical treatment purposes. METHODS 499 healthy condyles were examined in CT-based 3D models of Caucasians aged 8-88 years old. Datasets were obtained from 66 CBCT and 184 FBCT axial image series (in each case, imaging both mandible condyles resulted in the acquisition of 132 condyles from CBCT and 368 condyles from FBCT) and were transformed into three-dimensional models by digital segmentation. Eleven different measurements were performed to obtain information whether there were any differences between FBCT and CBCT models of the same anatomical region. RESULTS 7 of 11 dimensions were significantly higher in FBCT versus lower in CBCT (p < 0.05).
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Friedli L, Kloukos D, Kanavakis G, Halazonetis D, Gkantidis N. The effect of threshold level on bone segmentation of cranial base structures from CT and CBCT images. Sci Rep 2020; 10:7361. [PMID: 32355261 PMCID: PMC7193643 DOI: 10.1038/s41598-020-64383-9] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Accepted: 04/16/2020] [Indexed: 11/15/2022] Open
Abstract
The use of a single grey intensity threshold is one of the most straightforward and widely used methods to segment cranial base surface models from a 3D radiographic volume. In this study we used thirty Cone Beam Computer Tomography (CBCT) scans from three different machines and ten CT scans of growing individuals to test the effect of thresholding on the subsequently produced anterior cranial base surface models. From each scan, six surface models were generated using a range of voxel intensity thresholds. The models were then superimposed on a manually selected reference surface model, using an iterative closest point algorithm. Multivariate tests showed significant effects of the machine type, threshold value, and superimposition on the spatial position and the form of the created models. For both, CT and CBCT machines, the distance between the models, as well as the variation within each threshold category, was consistently increasing with the magnitude of difference between thresholds. The present findings highlight the importance of accurate anterior cranial base segmentation for reliable assessment of craniofacial morphology through surface superimposition or similar methods that utilize this anatomical structure as reference.
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Affiliation(s)
- Luca Friedli
- Department of Orthodontics and Dentofacial Orthopedics, University of Bern, CH-3010, Bern, Switzerland
| | - Dimitrios Kloukos
- Department of Orthodontics and Dentofacial Orthopedics, University of Bern, CH-3010, Bern, Switzerland.,Department of Orthodontics and Dentofacial Orthopedics, 251 Hellenic Air Force General Hospital, GR-11525, Athens, Greece
| | - Georgios Kanavakis
- Department of Pediatric Oral Health and Orthodontics, University Center for Dental Medicine - UZB, University of Basel, CH-4058, Basel, Switzerland
| | - Demetrios Halazonetis
- Department of Orthodontics, School of Dentistry, National and Kapodistrian University of Athens, GR-11527, Athens, Greece
| | - Nikolaos Gkantidis
- Department of Orthodontics and Dentofacial Orthopedics, University of Bern, CH-3010, Bern, Switzerland.
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Vandenberghe B. The crucial role of imaging in digital dentistry. Dent Mater 2020; 36:581-591. [PMID: 32299666 DOI: 10.1016/j.dental.2020.03.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Accepted: 03/09/2020] [Indexed: 10/24/2022]
Abstract
One of the recent trends in dentistry - and this in every field from the restorative to the orthodontic one- is the introduction of simplified completely digital workflows. Digital dentistry is supposed to allow dentists to work more efficiently, and this at higher precision, and with the possibility of all-in-one sessions using in-house computerized techniques. In this workflow, one of the major tools for simulating and transferring dental treatments is imaging. Both 3D low dose radiographic as well as optical imaging are playing crucial roles and have been overwhelming the market. Novel design platforms, compact and extremely fast milling and printing units are now also plentiful and rapidly being adopted in practice. Nevertheless, many of the steps in this digital dentistry process, no matter how simplified, present risks that can contribute to reduced precision and clinical difficulties. It is therefore the purpose of the article to briefly describe the role of imaging in this digital workflow, and where the pitfalls can be found that may lead to errors and imprecision.
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Affiliation(s)
- Bart Vandenberghe
- Advimago, Center for Advanced Oral Imaging, Emile Clausstraat 42, 1050 Brussels, Belgium.
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Durastanti G, Leardini A, Siegler S, Durante S, Bazzocchi A, Belvedere C. Comparison of cartilage and bone morphological models of the ankle joint derived from different medical imaging technologies. Quant Imaging Med Surg 2019; 9:1368-1382. [PMID: 31559166 DOI: 10.21037/qims.2019.08.08] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Background Accurate geometrical models of bones and cartilage are necessary in biomechanical modelling of human joints, and in planning and designing of joint replacements. Image-based subject-specific model development requires image segmentation, spatial filtering and 3-dimensional rendering. This is usually based on computed tomography (CT) for bone models, on magnetic resonance imaging (MRI) for cartilage models. This process has been reported extensively in the past, but no studies have ever compared the accuracy and quality of these models when obtained also by merging different imaging modalities. The scope of the present work is to provide this comparative analysis in order to identify optimal imaging modality and registration techniques for producing 3-dimensional bone and cartilage models of the ankle joint. Methods One cadaveric leg was instrumented with multimodal markers and scanned using five different imaging modalities: a standard, a dual-energy and a cone-beam CT (CBCT) device, and a 1.5 and 3.0 Tesla MRI devices. Bone, cartilage, and combined bone and cartilage models were produced from each of these imaging modalities, and registered in space according to matching model surfaces or to corresponding marker centres. To assess the quality in overall model reconstruction, distance map analyses were performed and the difference between model surfaces obtained from the different imaging modalities and registration techniques was measured. Results The registration between models worked better with model surface matching than corresponding marker positions, particularly with MRI. The best bone models were obtained with the CBCT. Models with cartilage were defined better with the 3.0 Tesla than the 1.5 Tesla. For the combined bone and cartilage models, the colour maps and the numerical results from distance map analysis (DMA) showed that the smallest distances and the largest homogeneity were obtained from the CBCT and the 3.0 T MRI via model surface registration. Conclusions These observations are important in producing accurate bone and cartilage models from medical imaging and relevant for applications such as designing of custom-made ankle replacements or, more in general, of implants for total as well as focal joint replacements.
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Affiliation(s)
- Gilda Durastanti
- Movement Analysis Laboratory, IRCCS Istituto Ortopedico Rizzoli, Bologna, Italy
| | - Alberto Leardini
- Movement Analysis Laboratory, IRCCS Istituto Ortopedico Rizzoli, Bologna, Italy
| | - Sorin Siegler
- Department of Mechanical Engineering and Mechanics, Drexel University, Philadelphia, PA, USA
| | - Stefano Durante
- Nursing, Technical and Rehabilitation Assistance Service, IRCCS Istituto Ortopedico Rizzoli, Bologna, Italy
| | - Alberto Bazzocchi
- Diagnostic and Interventional Radiology, IRCCS Istituto Ortopedico Rizzoli, Bologna, Italy
| | - Claudio Belvedere
- Movement Analysis Laboratory, IRCCS Istituto Ortopedico Rizzoli, Bologna, Italy
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Hilgenfeld T, Juerchott A, Deisenhofer UK, Weber D, Rues S, Rammelsberg P, Heiland S, Bendszus M, Schwindling FS. In vivo accuracy of tooth surface reconstruction based on CBCT and dental MRI-A clinical pilot study. Clin Oral Implants Res 2019; 30:920-927. [PMID: 31257638 DOI: 10.1111/clr.13498] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2019] [Revised: 06/11/2019] [Accepted: 06/18/2019] [Indexed: 11/29/2022]
Abstract
OBJECTIVES Guided implant surgery (GIS) requires alignment of virtual models to reconstructions of three-dimensional imaging. Accurate visualization of the tooth surfaces in the imaging datasets is mandatory. In this prospective clinical study, in vivo tooth surface accuracy was determined for GIS using cone-beam computed tomography (CBCT) and dental magnetic resonance imaging (dMRI). MATERIALS AND METHODS CBCT and 3-Tesla dMRI were performed in 22 consecutive patients (mean age: 54.4 ± 15.2 years; mean number of restorations per jaw: 6.7 ± 2.7). Altogether, 92 teeth were included (31 incisor, 29 canines, 20 premolars, and 12 molars). Surfaces were reconstructed semi-automatically and registered to a reference standard (3D scans of stone models made from full-arch polyether impressions). Reliability of both methods was assessed using intraclass correlation coefficients. Accuracy was evaluated using the two one-sided tests procedure with a predefined equivalence margin of ±0.2 mm root mean square (RMS). RESULTS Inter- and intrarater reliability of tooth surface reconstruction were comparable for CBCT and dMRI. Geometric deviations were 0.102 ± 0.042 mm RMS for CBCT and 0.261 ± 0.08 mm RMS for dMRI. For a predefined equivalence margin, CBCT and dMRI were statistically equivalent. CBCT, however, was significantly more accurate (p ≤ .0001). For both imaging techniques, accuracy did not differ substantially between different tooth types. CONCLUSION Cone-beam computed tomography is an accurate and reliable imaging technique for tooth surfaces in vivo, even in the presence of metal artifacts. In comparison, dMRI in vivo accuracy is lower. Still, it allows for tooth surface reconstruction in satisfactory detail and within acceptable acquisition times.
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Affiliation(s)
- Tim Hilgenfeld
- Department of Neuroradiology, Heidelberg University Hospital, Heidelberg, Germany
| | - Alexander Juerchott
- Department of Neuroradiology, Heidelberg University Hospital, Heidelberg, Germany
| | | | - Dorothea Weber
- Institute of Medical Biometry and Informatics (IMBI), Heidelberg University Hospital, Heidelberg, Germany
| | - Stefan Rues
- Department of Prosthodontics, Heidelberg University Hospital, Heidelberg, Germany
| | - Peter Rammelsberg
- Department of Prosthodontics, Heidelberg University Hospital, Heidelberg, Germany
| | - Sabine Heiland
- Department of Neuroradiology, Heidelberg University Hospital, Heidelberg, Germany
| | - Martin Bendszus
- Department of Neuroradiology, Heidelberg University Hospital, Heidelberg, Germany
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11
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Jo DW, Cho YD, Seol YJ, Lee YM, Lee HJ, Kim YK. A randomized controlled clinical trial evaluating efficacy and adverse events of different types of recombinant human bone morphogenetic protein-2 delivery systems for alveolar ridge preservation. Clin Oral Implants Res 2019; 30:396-409. [PMID: 30883942 DOI: 10.1111/clr.13423] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2018] [Revised: 01/29/2019] [Accepted: 01/29/2019] [Indexed: 11/30/2022]
Abstract
OBJECTIVES This 12-week clinical trial evaluated efficacy and adverse events for two recombinant human bone morphogenetic protein-2 (rhBMP-2) delivery systems in alveolar ridge preservation. MATERIALS AND METHODS Sixty-four patients had a single tooth that required replacement with an implant, surrounded by > 50% alveolar bone height. Two cohorts (n = 32 patients each) were randomized to receive a rhBMP-2-soaked absorbable collagen sponge (test group), or β-tricalcium phosphate and hydroxyapatite particles (control group) immersed in rhBMP-2, at the implant site. Bone height and width changes at 25%, 50%, and 75% of extraction socket level (ESL) were compared. Adverse events were assessed in the same period. In addition to the randomized controlled clinical trial, histological analysis of 21 patients (test group [n = 12], control group [n = 9]) was conducted, 4 months after alveolar ridge preservation. A non-inferiority test was used to analyze changes in alveolar bone height between groups (p = 0.05). A Wilcoxon rank-sum test was used to analyze changes in alveolar bone width and histomorphometric results between groups (p = 0.05). RESULTS All patients showed good healing without severe adverse events. The lower limit of the one-sided 97.5% confidence interval in the difference between the two groups was 0.0033 (non-inferiority margin: -0.185); thus, the test group showed non-inferiority to the control group. Wilcoxon rank-sum test analysis did not show statistically significant differences between groups with regard to changes in alveolar bone width and histomorphometric analysis. CONCLUSIONS The delivery systems showed similar efficacy for alveolar ridge preservation without severe adverse events.
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Affiliation(s)
- Deuk-Won Jo
- Department of Prosthodontics, Section of Dentistry, Seoul National University Bundang Hospital, Seongnam, Korea
| | - Young-Dan Cho
- Department of Periodontology & Dental Research Institute, School of Dentistry, Seoul National University, Seoul, Korea
| | - Yang-Jo Seol
- Department of Periodontology & Dental Research Institute, School of Dentistry, Seoul National University, Seoul, Korea
| | - Yong-Moo Lee
- Department of Periodontology & Dental Research Institute, School of Dentistry, Seoul National University, Seoul, Korea
| | - Hyo-Jung Lee
- Department of Periodontology, Section of Dentistry, Seoul National University Bundang Hospital, Seongnam, Korea
| | - Young-Kyun Kim
- Department of Oral and Maxillofacial Surgery, Section of Dentistry, Seoul National University Bundang Hospital, Seongnam, Korea.,Department of Dentistry & Dental Research Institute, School of Dentistry, Seoul National University, Seoul, Korea
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Kulah K, Gulsahi A, Kamburoğlu K, Geneci F, Ocak M, Celik HH, Ozen T. Evaluation of maxillary trabecular microstructure as an indicator of implant stability by using 2 cone beam computed tomography systems and micro-computed tomography. Oral Surg Oral Med Oral Pathol Oral Radiol 2018; 127:247-256. [PMID: 30595501 DOI: 10.1016/j.oooo.2018.11.014] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2017] [Revised: 08/15/2018] [Accepted: 11/21/2018] [Indexed: 11/30/2022]
Abstract
OBJECTIVE The aim of this study was to assess the trabecular microarchitecture of the maxilla by using cone beam computed tomography (CBCT) and micro-computed tomography (micro-CT) ex vivo. STUDY DESIGN Seventeen maxillary cadaver specimens were scanned by using micro-CT and CBCT devices. Samples were scanned with 2 CBCT devices at different voxel sizes (0.08, 0.125, and 0.160 mm for 3-D Accuitomo 170; 0.75 and 0.200 mm for Planmeca Promax 3-D Max). Morphometric parameters, such as bone volume/total volume (BV/TV) ratio, trabecular thickness (Tb.Th), trabecular separation (Tb.Sp), trabecular number (Tb.N), and degree of anisotropy (DA) were assessed by using CTAnalyzer software. Bland-Altman limits of agreement and intraclass correlation coefficient (ICC) were performed to evaluate agreement between CBCT and micro-CT in consideration of measured morphometric parameters. Statistical significance was set at P < .05. RESULTS The BV/TV, Tb.Th, Tb.Sp, and DA values were higher for CBCT images compared with micro-CT images, whereas the Tb.N value was lower with CBCT images than with micro-CT images. The BV/TV and DA parameters showed the highest agreement between CBCT and micro-CT devices (ICC = 0.421 for BV/TV and ICC = 0.439 for DA; P < .01). CONCLUSIONS The BV/TV and DA parameters measured on CBCT obtained at the smallest voxel size were found to be useful for the assessment of maxillary trabecular microstructure.
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Affiliation(s)
- Kıvanc Kulah
- Department of Dentomaxillofacial Radiology, Antalya Dental Health Center, Antalya, Turkey
| | - Ayse Gulsahi
- Department of Dentomaxillofacial Radiology, Faculty of Dentistry, Baskent University, Ankara, Turkey
| | - Kıvanç Kamburoğlu
- Department of Dentomaxillofacial Radiology, Faculty of Dentistry, Ankara University, Ankara, Turkey.
| | - Ferhat Geneci
- Department of Anatomy, Faculty of Medicine, Hacettepe University, Ankara, Turkey
| | - Mert Ocak
- Department of Anatomy, Faculty of Medicine, Hacettepe University, Ankara, Turkey
| | - H Hamdi Celik
- Department of Anatomy, Faculty of Medicine, Hacettepe University, Ankara, Turkey
| | - Tuncer Ozen
- Department of Dentomaxillofacial Radiology, Faculty of Dentistry, Gulhane Health Sciences University, Ankara, Turkey
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Budzik G, Turek P. Improved accuracy of mandible geometry reconstruction at the stage of data processing and modeling. AUSTRALASIAN PHYSICAL & ENGINEERING SCIENCES IN MEDICINE 2018; 41:687-695. [PMID: 29978281 PMCID: PMC6133077 DOI: 10.1007/s13246-018-0664-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/21/2017] [Accepted: 07/02/2018] [Indexed: 01/27/2023]
Abstract
The article presents a comparative study of influence of the Lanczos resampling filter on improving the accuracy of reconstruction of mandible geometries. The research was performed on eight different patients. Digital Imaging and Communications in Medicine data were obtained on the Siemens Somatom Sensation Open 40 scanner. At the stage of reconstruction, the same parameters were utilized, while only slice thickness was changed. Modeling with voxel dimensions of 0.4 mm × 0.4 mm × 1.5 mm was chosen as the gold standard over the modeling approach comprising voxel dimensions of 0.4 mm × 0.4 mm × 3.0 mm and improved using the Lanczos resampling filter. The influence of the Lanczos resampling filter on the accuracy of reconstruction of mandible geometry is very similar for the eight presented patients. The average results show a distribution with a positive skew and kurtosis. The value of skewness is 0.713 and kurtosis is 4.221 for the model without Lanczos filtering applied. When the Lanczos filtering is applied the value of skewness is 0.542 and kurtosis is 4.313. Based on 95% confidence, changes in layer thickness from 1.5 mm to 3 mm generated errors reconstructing the geometry of the mandible at the value of 0.153 mm ± 1.209 mm. In models improved using the Lanczos resampling filter, the errors generated in reconstructing the geometry of the mandible were minimized at the value of 0.160 mm ± 1.007 mm. The presented research highlights new opportunities to improve the accuracy of reconstruction geometry of the mandible at the stage of data processing.
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Affiliation(s)
- Grzegorz Budzik
- Faculty of Mechanical Engineering & Aeronautics, Rzeszow University of Technology, Powstańców Warszawy Avenue 12, 35-959 Rzeszow, Poland
| | - Paweł Turek
- Faculty of Mechanical Engineering & Aeronautics, Rzeszow University of Technology, Powstańców Warszawy Avenue 12, 35-959 Rzeszow, Poland
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Bornstein MM, Horner K, Jacobs R. Use of cone beam computed tomography in implant dentistry: current concepts, indications and limitations for clinical practice and research. Periodontol 2000 2018; 73:51-72. [PMID: 28000270 DOI: 10.1111/prd.12161] [Citation(s) in RCA: 83] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Diagnostic radiology is an essential component of treatment planning in the field of implant dentistry. This narrative review will present current concepts for the use of cone beam computed tomography imaging, before and after implant placement, in daily clinical practice and research. Guidelines for the selection of three-dimensional imaging will be discussed, and limitations will be highlighted. Current concepts of radiation dose optimization, including novel imaging modalities using low-dose protocols, will be presented. For preoperative cross-sectional imaging, data are still not available which demonstrate that cone beam computed tomography results in fewer intraoperative complications such as nerve damage or bleeding incidents, or that implants inserted using preoperative cone beam computed tomography data sets for planning purposes will exhibit higher survival or success rates. The use of cone beam computed tomography following the insertion of dental implants should be restricted to specific postoperative complications, such as damage of neurovascular structures or postoperative infections in relation to the maxillary sinus. Regarding peri-implantitis, the diagnosis and severity of the disease should be evaluated primarily based on clinical parameters and on radiological findings based on periapical radiographs (two dimensional). The use of cone beam computed tomography scans in clinical research might not yield any evident beneficial effect for the patient included. As many of the cone beam computed tomography scans performed for research have no direct therapeutic consequence, dose optimization measures should be implemented by using appropriate exposure parameters and by reducing the field of view to the actual region of interest.
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Scarfe WC, Azevedo B, Toghyani S, Farman AG. Cone Beam Computed Tomographic imaging in orthodontics. Aust Dent J 2017; 62 Suppl 1:33-50. [PMID: 28297089 DOI: 10.1111/adj.12479] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Over the last 15 years, cone beam computed tomographic (CBCT) imaging has emerged as an important supplemental radiographic technique for orthodontic diagnosis and treatment planning, especially in situations which require an understanding of the complex anatomic relationships and surrounding structures of the maxillofacial skeleton. CBCT imaging provides unique features and advantages to enhance orthodontic practice over conventional extraoral radiographic imaging. While it is the responsibility of each practitioner to make a decision, in tandem with the patient/family, consensus-derived, evidence-based clinical guidelines are available to assist the clinician in the decision-making process. Specific recommendations provide selection guidance based on variables such as phase of treatment, clinically-assessed treatment difficulty, the presence of dental and/or skeletal modifying conditions, and pathology. CBCT imaging in orthodontics should always be considered wisely as children have conservatively, on average, a three to five times greater radiation risk compared with adults for the same exposure. The purpose of this paper is to provide an understanding of the operation of CBCT equipment as it relates to image quality and dose, highlight the benefits of the technique in orthodontic practice, and provide guidance on appropriate clinical use with respect to radiation dose and relative risk, particularly for the paediatric patient.
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Affiliation(s)
- W C Scarfe
- Division of Radiology and Imaging Sciences, Department of Surgical and Hospital Dentistry, The University of Louisville School of Dentistry, Louisville, Kentucky, USA
| | - B Azevedo
- Division of Radiology and Imaging Sciences, Department of Surgical and Hospital Dentistry, The University of Louisville School of Dentistry, Louisville, Kentucky, USA
| | - S Toghyani
- Division of Radiology and Imaging Sciences, Department of Surgical and Hospital Dentistry, The University of Louisville School of Dentistry, Louisville, Kentucky, USA
| | - A G Farman
- University of Louisville School of Dentistry and Independent Consultant in Oral and Maxillofacial Radiology, Chicago, Illinois, USA
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İşman Ö, Yılmaz HH, Aktan AM, Yilmaz B. Indications for cone beam computed tomography in children and young patients in a Turkish subpopulation. Int J Paediatr Dent 2017; 27:183-190. [PMID: 27452447 DOI: 10.1111/ipd.12250] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
BACKGROUND Cone beam computed tomography (CBCT) imaging is widely used in children; however, it remains controversial because of the health effects of radiation. AIM This retrospective study investigated the indications for CBCT and dentomaxillofacial pathologies in paediatric patients. MATERIALS AND METHODS CBCT images of 329 paediatric patients (i.e., aged <18 years) were investigated retrospectively. CBCT images were obtained with five fields of view (FOV). CBCT indications were categorised as surgery and orthodontics. The effects of age, sex, and FOV were evaluated. The level of significance was P = 0.05. RESULTS The most common orthodontic indications were malocclusion and dentomaxillofacial anomalies (38.5%), followed by the localisation of impacted teeth (33.1%). There was no relationship between sex and indications. There were significant associations between age groups and malocclusion and dentomaxillofacial anomalies, localisation of impacted teeth, and trauma. The face was the most frequently imaged region, followed by the jaws (maxilla and mandible). CONCLUSION The most common indication for CBCT was malocclusion and dentomaxillofacial anomalies in the primary and permanent dentition age groups, whereas the localisation of impacted teeth was the most common indication in the mixed dentition age group. Generally, CBCT was indicated in orthodontics and surgery.
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Affiliation(s)
- Özlem İşman
- Department of Dentomaxillofacial Radiology, Faculty of Dentistry, Gaziantep University, Gaziantep, Turkey
| | - Hasan Hüseyin Yılmaz
- Department of Dentomaxillofacial Radiology, Faculty of Dentistry, Şifa University, İzmir, Turkey
| | - Ali Murat Aktan
- Department of Dentomaxillofacial Radiology, Faculty of Dentistry, Uşak University, Uşak, Turkey
| | - Büşra Yilmaz
- Department of Dentomaxillofacial Radiology, Faculty of Dentistry, Gaziantep University, Gaziantep, Turkey
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Zain Alabdeen EH. Accuracy of half-exposure time in cone-beam computed tomography imaging for the detection of surface osseous changes in the temporomandibular joint. Oral Radiol 2016. [DOI: 10.1007/s11282-016-0256-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Fakhar HB, Mallahi M, Panjnoush M, Kashani PM. Effect of Voxel Size and Object Location in the Field of View on Detection of Bone Defects in Cone Beam Computed Tomography. JOURNAL OF DENTISTRY (TEHRAN, IRAN) 2016; 13:279-286. [PMID: 28127320 PMCID: PMC5253221] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
OBJECTIVES This study aimed to assess the effect of voxel size and object location in the field of view (FOV) on diagnostic accuracy of cone beam computed tomography (CBCT) for detection of simulated bone defects. MATERIALS AND METHODS In this in vitro study, bone defects were drilled in four sections of a dry human mandible. Bone blocks were fixed on a platform parallel to the horizontal plane and CBCT images were acquired using 0.2mm and 0.3mm resolutions and five locations of FOV (anterior, posterior, left, right and center). Three reviewers viewed the images twice and the presence or absence of simulated bone defects was determined in positive and negative cases. RESULTS Sensitivity in different locations of FOV ranged between 0.25-1.0 and 0.75-1.0 in low and high resolutions, respectively. These values were 0.625-1.0 and 0.69-1.0, respectively for specificity. Intra-observer agreements were in the range of 0.84-1.0 and 0.75-1.0 and inter-observer agreements were in the range of 0.3-0.61 and 0.46-0.69 in high and low resolutions, respectively. The highest sensitivity was seen at the center of the FOV and with an increase in resolution from 0.3mm to 0.2mm, the sensitivity increased specially in the posterior region of the FOV while image resolutions and FOV locations did not affect specificity. CONCLUSIONS The highest sensitivity values were obtained at the center of the FOV and lowest values were seen in images acquired in the posterior region in low resolution. Diagnostic accuracy improved with increased resolution.
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Affiliation(s)
- Hoorieh Bashizadeh Fakhar
- Assistant Professor, Department of Oral and Maxillofacial Radiology, School of Dentistry, Tehran University of Medical Sciences, Tehran, Iran
| | - Mysa Mallahi
- Assistant Professor, Department of Oral and Maxillofacial Radiology, Faculty of Dentistry, Golestan University of Medical Sciences, Gorgan, Iran,Corresponding author: M. Mallahi, Department of Oral and Maxillofacial Radiology, Faculty of Dentistry, Golestan University of Medical Sciences, Gorgan, Iran,
| | - Mehrdad Panjnoush
- Assistant Professor, Department of Oral and Maxillofacial Radiology, School of Dentistry, Tehran University of Medical Sciences, Tehran, Iran
| | - Pooneh Mohseni Kashani
- Postgraduate Student, Department of Oral and Maxillofacial Radiology, School of Dentistry, Tehran University of Medical Sciences, Tehran, Iran
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Goulston R, Davies J, Horner K, Murphy F. Dose optimization by altering the operating potential and tube current exposure time product in dental cone beam CT: a systematic review. Dentomaxillofac Radiol 2016; 45:20150254. [PMID: 26732433 DOI: 10.1259/dmfr.20150254] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
OBJECTIVES Current guidelines highlight the need to optimize exposure parameters on CBCT equipment to levels that are as low as diagnostically acceptable. This systematic review aimed to answer the question "Can altering operating potential (kV) and tube current exposure time product (mAs) on CBCT machines reduce radiation dose to patients undergoing dental and/or maxillofacial scans without a detrimental impact on image quality/diagnostic accuracy?" METHODS Studies were selected and results reported following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) method. For each individual study, two authors (RG and JD or KH) independently extracted data using a specifically designed collection form, and an overall quality value was assigned using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) system. Any disagreements in the overall quality value of a study were resolved by discussion between the current authors. RESULTS Nearly 75% of studies were considered to be of low or very low methodological quality using the GRADE system, and more studies stated that their results applied only in the specific situations they had investigated. However, most studies demonstrated that patient dose reduction is possible without a clinically relevant reduction in image quality. CONCLUSIONS For many CBCT machines, it should be possible to optimize one, or more, of the investigated exposure parameters and therefore reduce patient radiation dose, while maintaining diagnostic image quality for some diagnostic tasks. However, more rigorous research is still required.
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Affiliation(s)
- Rebekah Goulston
- 1 Dental Radiology Department, University Dental Hospital of Manchester, Manchester, UK
| | - Jonathan Davies
- 2 University of Manchester, School of Dentistry, Manchester, UK
| | - Keith Horner
- 2 University of Manchester, School of Dentistry, Manchester, UK
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20
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Hidalgo Rivas JA, Horner K, Thiruvenkatachari B, Davies J, Theodorakou C. Development of a low-dose protocol for cone beam CT examinations of the anterior maxilla in children. Br J Radiol 2015; 88:20150559. [PMID: 26279087 DOI: 10.1259/bjr.20150559] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
OBJECTIVE The aim of this study was to develop a low-dose protocol suitable for cone beam CT (CBCT) examination of an impacted maxillary canine in children by using a combination of dosimetry with subjective and objective image quality assessment. METHODS Radiation dose and image quality measurements were made using a dental CBCT machine. An image quality phantom was used to investigate the relationship between objective image quality and dose-area product (DAP) for a broad range of exposure settings. Subjective image quality assessment was achieved using a paediatric skull phantom submerged in a water bath for the same range of exposure settings. Eight clinicians assessed each CBCT data set for nine aspects of image quality using a five-point rating scale of agreement. RESULTS Acceptable image quality, defined using subjective judgements by the clinicians of the skull phantom images, was achievable with DAP values of 127 mGy cm(2) or greater and a polytetrafluoroethylene (PTFE) contrast-to-noise ratio (CNR) of 4.8 or greater. A cautious choice was made to recommend a low-dose protocol of 80 kV and 3 mA for implementation into clinical practice, corresponding to a DAP value of 146 mGy cm(2) and a PTFE CNR of 5.0. CONCLUSION A low-dose protocol for this particular CBCT machine was established which represents as much as a 50% reduction compared with manufacturer's recommendations. ADVANCES IN KNOWLEDGE To the authors' best knowledge, this is the first study that addresses dose optimization in paediatric clinical protocols in dental CBCT. Furthermore, this study explores the relationship between radiation dose, objective and subjective image quality.
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Affiliation(s)
- Jose A Hidalgo Rivas
- 1 School of Dentistry, The University of Manchester, Manchester Academic Health Science Centre, Manchester, UK
| | - Keith Horner
- 1 School of Dentistry, The University of Manchester, Manchester Academic Health Science Centre, Manchester, UK
| | - Badri Thiruvenkatachari
- 1 School of Dentistry, The University of Manchester, Manchester Academic Health Science Centre, Manchester, UK
| | - Jonathan Davies
- 1 School of Dentistry, The University of Manchester, Manchester Academic Health Science Centre, Manchester, UK
| | - Chrysoula Theodorakou
- 2 Christie Medical Physics and Engineering, The Christie NHS Foundation Trust, Manchester Academic Health Science Centre, Manchester, UK (Hidalgo Rivas is now with Depto. de Estomologia, Universidad deTalca, Talca, Chile)
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Meireles AB, Vieira AW, Corpas L, Vandenberghe B, Bastos FS, Lambrechts P, Campos MM, Las Casas EBD. Dental wear estimation using a digital intra-oral optical scanner and an automated 3D computer vision method. Comput Methods Biomech Biomed Engin 2015; 19:507-14. [PMID: 26047162 DOI: 10.1080/10255842.2015.1043627] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
The objective of this work was to propose an automated and direct process to grade tooth wear intra-orally. Eight extracted teeth were etched with acid for different times to produce wear and scanned with an intra-oral optical scanner. Computer vision algorithms were used for alignment and comparison among models. Wear volume was estimated and visual scoring was achieved to determine reliability. Results demonstrated that it is possible to directly detect submillimeter differences in teeth surfaces with an automated method with results similar to those obtained by direct visual inspection. The investigated method proved to be reliable for comparison of measurements over time.
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Affiliation(s)
| | - Antonio Wilson Vieira
- b Department of Mathematics , Universidade Estadual de Montes Claros , Montes Claros , Brazil
| | - Livia Corpas
- c BIOMAT, Department of Oral Health Sciences , Katholieke Universiteit Leuven , Leuven , Belgium
| | - Bart Vandenberghe
- c BIOMAT, Department of Oral Health Sciences , Katholieke Universiteit Leuven , Leuven , Belgium
| | - Flavia Souza Bastos
- d Department of Computational and Applied Mechanics , Universidade Federal de Juiz de Fora , Juiz de Fora , Brazil
| | - Paul Lambrechts
- c BIOMAT, Department of Oral Health Sciences , Katholieke Universiteit Leuven , Leuven , Belgium
| | - Mario Montenegro Campos
- e Computer Science Department , Universidade Federal de Minas Gerais , Belo Horizonte , Brazil
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Vallaeys K, Kacem A, Legoux H, Le Tenier M, Hamitouche C, Arbab-Chirani R. 3D dento-maxillary osteolytic lesion and active contour segmentation pilot study in CBCT: semi-automatic vs manual methods. Dentomaxillofac Radiol 2015; 44:20150079. [PMID: 25996572 DOI: 10.1259/dmfr.20150079] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
OBJECTIVES This study was designed to evaluate the reliability of a semi-automatic segmentation tool for dento-maxillary osteolytic image analysis compared with manually defined segmentation in CBCT scans. METHODS Five CBCT scans were selected from patients for whom periapical radiolucency images were available. All images were obtained using a ProMax® 3D Mid Planmeca (Planmeca Oy, Helsinki, Finland) and were acquired with 200-μm voxel size. Two clinicians performed the manual segmentations. Four operators applied three different semi-automatic procedures. The volumes of the lesions were measured. An analysis of dispersion was made for each procedure and each case. An ANOVA was used to evaluate the operator effect. Non-paired t-tests were used to compare semi-automatic procedures with the manual procedure. Statistical significance was set at α = 0.01. RESULTS The coefficients of variation for the manual procedure were 2.5-3.5% on average. There was no statistical difference between the two operators. The results of manual procedures can be used as a reference. For the semi-automatic procedures, the dispersion around the mean can be elevated depending on the operator and case. ANOVA revealed significant differences between the operators for the three techniques according to cases. CONCLUSIONS Region-based segmentation was only comparable with the manual procedure for delineating a circumscribed osteolytic dento-maxillary lesion. The semi-automatic segmentations tested are interesting but are limited to complex surface structures. A methodology that combines the strengths of both methods could be of interest and should be tested. The improvement in the image analysis that is possible through the segmentation procedure and CBCT image quality could be of value.
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Affiliation(s)
- K Vallaeys
- 1 UFR d'Odontologie, Université de Bretagne Occidentale, Brest, France.,2 Laboratoire de Traitement de I'Information Médicale, LaTim-Inserm UMR 1101, Brest, France.,3 Service d'Odontologie, Centre Hospitalier Régional Universitaire Brest, France
| | - A Kacem
- 2 Laboratoire de Traitement de I'Information Médicale, LaTim-Inserm UMR 1101, Brest, France.,4 Départment Image et Traitement de I'Information, Telecom Bretagne, Brest, France.,5 Institut National des Sciences Appliquées et de Technologies de Tunis, INSAT, Tunis, Tunisia
| | - H Legoux
- 1 UFR d'Odontologie, Université de Bretagne Occidentale, Brest, France.,3 Service d'Odontologie, Centre Hospitalier Régional Universitaire Brest, France
| | - M Le Tenier
- 1 UFR d'Odontologie, Université de Bretagne Occidentale, Brest, France.,3 Service d'Odontologie, Centre Hospitalier Régional Universitaire Brest, France
| | - C Hamitouche
- 2 Laboratoire de Traitement de I'Information Médicale, LaTim-Inserm UMR 1101, Brest, France.,4 Départment Image et Traitement de I'Information, Telecom Bretagne, Brest, France
| | - R Arbab-Chirani
- 1 UFR d'Odontologie, Université de Bretagne Occidentale, Brest, France.,2 Laboratoire de Traitement de I'Information Médicale, LaTim-Inserm UMR 1101, Brest, France.,3 Service d'Odontologie, Centre Hospitalier Régional Universitaire Brest, France
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Jacobs R, Quirynen M. Dental cone beam computed tomography: justification for use in planning oral implant placement. Periodontol 2000 2014; 66:203-13. [DOI: 10.1111/prd.12051] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/12/2013] [Indexed: 01/17/2023]
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Jacobs R, Quirynen M, Bornstein MM. Neurovascular disturbances after implant surgery. Periodontol 2000 2014; 66:188-202. [DOI: 10.1111/prd.12050] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/12/2013] [Indexed: 11/29/2022]
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Nackaerts O, Depypere M, Zhang G, Vandenberghe B, Maes F, Jacobs R. Segmentation of Trabecular Jaw Bone on Cone Beam CT Datasets. Clin Implant Dent Relat Res 2014; 17:1082-91. [PMID: 24629139 DOI: 10.1111/cid.12217] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BACKGROUND The term bone quality is often used in a dentomaxillofacial context, for example in implant planning, as bone density and bone structure have been linked to primary implant success. PURPOSE This research aimed to investigate the performance of adaptive thresholding of trabecular bone in cone beam CT (CBCT) images. The segmentation quality was assessed for different imaging devices and upper and lower jaws. MATERIALS AND METHODS Four jaws were scanned with eight CBCT scanners and one micro-CT device. Images of the jaws were spatially aligned with the micro-CT images. Two volumes of interest for each jaw were manually delineated. Trabecular bone in the volumes of interest in the micro-CT images was segmented so that the micro-CT images could serve as high-resolution ground truth images. The volumes of interest in the CBCT images were segmented using both global and adaptive thresholding. RESULTS Segmentation was significantly better for the lower jaw than for the upper jaw. Differences in performance between the scanners were significant for both jaws. Adaptive thresholding performed significantly better in segmenting the bone structure out of CBCT images. CONCLUSIONS When assessing jaw bone structure, the observer should always choose adaptive thresholding. It remains a challenge to identify the optimal threshold selection for the structural assessment of jaw bone.
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Affiliation(s)
- Olivia Nackaerts
- OMFS-IMPATH Research Group, Department of Imaging & Pathology, KU Leuven, Leuven, Belgium
| | - Maarten Depypere
- Medical Image Computing, Center for Processing Speech and Images, Department of Electrical Engineering, KU Leuven, Leuven, Belgium
| | - Guozhi Zhang
- Leuven University Centre for Medical Physics in Radiology, University Hospitals Leuven, Leuven, Belgium
| | | | - Frederik Maes
- Medical Image Computing, Center for Processing Speech and Images, Department of Electrical Engineering & iMinds, KU Leuven, Leuven, Belgium
| | - Reinhilde Jacobs
- OMFS-IMPATH Research Group, Department of Imaging & Pathology, KU Leuven, Leuven, Belgium
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Yilmaz SY, Misirlioglu M, Adisen MZ. A Diagnosis of Maxillary Sinus Fracture with Cone-Beam CT: Case Report and Literature Review. Craniomaxillofac Trauma Reconstr 2014; 7:85-91. [PMID: 25045417 DOI: 10.1055/s-0034-1371550] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2013] [Accepted: 04/14/2013] [Indexed: 10/25/2022] Open
Abstract
The purpose of this article is to present the case of maxillofacial trauma patient with maxillary sinus fracture diagnosed with cone-beam computed tomography (CBCT) and to explore the applications of this technique in evaluating the maxillofacial region. A 23-year-old male patient attempted to our clinic who had an injury at midface with complaints of swelling, numbness. The patient was examined before in emergency center but any diagnosis was made about the maxillofacial trauma. The patient re-examined clinically and radiographically. A fracture on the frontal wall of maxillary sinus is determined with the aid of CBCT. The patient consulted with the department of maxillofacial surgery and it is decided that any surgical treatment was not necessary. The emerging technique CBCT would not be the primary choice of imaging maxillofacial trauma. Nevertheless, when advantages considered this imaging procedure could be the modality of choice according to the case.
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Affiliation(s)
- Selmi Yardimci Yilmaz
- Department of Maxillofacial Radiology, Faculty of Dentistry, Kirikkale University, Kirikkale, Turkey
| | - Melda Misirlioglu
- Department of Maxillofacial Radiology, Faculty of Dentistry, Kirikkale University, Kirikkale, Turkey
| | - Mehmet Zahit Adisen
- Department of Maxillofacial Radiology, Faculty of Dentistry, Kirikkale University, Kirikkale, Turkey
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Ibrahim N, Parsa A, Hassan B, van der Stelt P, Aartman IHA, Nambiar P. Influence of object location in different FOVs on trabecular bone microstructure measurements of human mandible: a cone beam CT study. Dentomaxillofac Radiol 2013; 43:20130329. [PMID: 24265395 DOI: 10.1259/dmfr.20130329] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
The aim of this study was to assess the influence of different object locations in different fields of view (FOVs) of two cone beam CT (CBCT) systems on trabecular bone microstructure measurements of a human mandible. A block of dry human mandible was scanned at five different locations (centre, left, right, anterior and posterior) using five different FOVs of two CBCT systems (NewTom™ 5G; QR Verona, Verona, Italy and Accuitomo 170; Morita, Kyoto, Japan). Image analysis software (CTAn software v. 1.1; SkyScan, Kontich, Belgium) was used to assess the trabecular bone microstructural parameters (thickness, Tb.Th; spacing, Tb.Sp; number, Tb.N; bone volume density, BV/TV). All measurements were taken twice by one trained observer. Tb.Th, Tb.Sp and Tb.N varied significantly across different FOVs in the NewTom 5G (p < 0.001) and the Accuitomo 170 (p < 0.001). For location, a significant difference was observed only when measuring BV/TV (p = 0.03) using the NewTom 5G. The trabecular bone microstructural measurements obtained from CBCT systems are influenced by the size of FOVs. Not all trabecular bone parameters measured using different CBCT systems are affected when varying the object location within the FOVs.
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Affiliation(s)
- N Ibrahim
- Department of General and Specialized Dentistry, Section of Oral and Maxillofacial Radiology, Academic Center for Dentistry Amsterdam (ACTA), Amsterdam, Netherlands
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Cone-beam computed tomography and microtomography for alveolar bone measurements. Surg Radiol Anat 2013; 35:495-502. [DOI: 10.1007/s00276-013-1080-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2012] [Accepted: 01/24/2013] [Indexed: 10/27/2022]
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Volume reduction of cystic lesions after surgical decompression: a computerised three-dimensional computed tomographic evaluation. Clin Oral Investig 2012; 17:1701-8. [DOI: 10.1007/s00784-012-0869-z] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2012] [Accepted: 10/17/2012] [Indexed: 10/27/2022]
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