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1.
George Puthenpurayil John Tatu Elenjickal Joy Justin Mathew Vinod R. B. Kumar 《Journal of Indian Prosthodontic Society》2015,15(1):8-13
Cone beam computed tomography (CBCT, also referred to as C-arm computed tomography [CT], cone beam volume CT, or flat panel CT) is a medical imaging technique of X-ray CT where the X-rays are divergent, forming a cone.[1] CBCT systems have been designed for imaging hard tissues of the maxillofacial region. CBCT is capable of providing sub-millimeter resolution in images of high diagnostic quality, with short scanning times (10–70 s) and radiation dosages reportedly up to 15–100 times lower than those of conventional CT scans. Increasing availability of this technology provides the dental clinician with an imaging modality capable of providing a three-dimensional representation of the maxillofacial skeleton with minimal distortion. The aim of this article is to sensitize the Prosthodontist to CBCT technology, provide an overview of currently available maxillofacial CBCT systems and review the specific application of various CBCT display modes to clinical Prosthodontic practice. A MEDLINE search for relevant articles in this specific area of interest was conducted. The selected articles were critically reviewed and the data acquired were systematically compiled.Key Words: Artefact reduction, cone beam computed tomography, dose reduction, fundamentals, imaging accuracy, prosthodontics 相似文献
2.
P. Pittayapat D. Galiti Y. Huang K. Dreesen M. Schreurs P. Couto Souza I. R. F. Rubira-Bullen F. H. Westphalen R. Pauwels G. Kalema G. Willems R Jacobs 《Clinical oral investigations》2013,17(1):293-300
Objectives
The objective of this study is to compare subjective image quality and diagnostic validity of cone-beam CT (CBCT) panoramic reformatting with digital panoramic radiographs.Materials and methods
Four dry human skulls and two formalin-fixed human heads were scanned using nine different CBCTs, one multi-slice CT (MSCT) and one standard digital panoramic device. Panoramic views were generated from CBCTs in four slice thicknesses. Seven observers scored image quality and visibility of 14 anatomical structures. Four observers repeated the observation after 4 weeks.Results
Digital panoramic radiographs showed significantly better visualization of anatomical structures except for the condyle. Statistical analysis of image quality showed that the 3D imaging modalities (CBCTs and MSCT) were 7.3 times more likely to receive poor scores than the 2D modality. Yet, image quality from NewTom VGi® and 3D Accuitomo 170® was almost equivalent to that of digital panoramic radiographs with respective odds ratio estimates of 1.2 and 1.6 at 95% Wald confidence limits. A substantial overall agreement amongst observers was found. Intra-observer agreement was moderate to substantial.Conclusions
While 2D-panoramic images are significantly better for subjective diagnosis, 2/3 of the 3D-reformatted panoramic images are moderate or good for diagnostic purposes.Clinical relevance
Panoramic reformattings from particular CBCTs are comparable to digital panoramic images concerning the overall image quality and visualization of anatomical structures. This clinically implies that a 3D-derived panoramic view can be generated for diagnosis with a recommended 20-mm slice thickness, if CBCT data is a priori available for other purposes. 相似文献3.
Hechang Huang Michael Richards Tamer Bedair Henry W. Fields J. Martin Palomo William M. Johnston Do-Gyoon Kim 《Clinical oral investigations》2013,17(9):2033-2040
Objectives
The objective of this study was to examine if non-invasive clinical cone beam computed tomography (CBCT)-based degree of bone mineralization (DBM) measurement can be used to detect the different results from orthodontic treatment between the maxilla and mandible in human patients.Materials and methods
CBCT images were taken before and after orthodontic treatment from 43 patients (19 males and 24 females, 14.36?±?1.50 years). A histogram of computed tomography (CT) attenuation value, which is equivalent to the DBM, was obtained from the alveolar cortical (AC), trabecular (AT), and enamel (E) regions of each image. Mean, standard deviation (SD), and coefficient of variation (COV) of the CT attenuation values were computed. The regional variations and percentage (%) differences between the E and alveolar regions of the CT attenuation parameters at the maxilla and mandible were analyzed before and after orthodontic treatment.Results
The AC had higher mean and variability (SD and COV) than the AT before and after treatment (p?<?0.001). The variability was higher in the mandibular AC than in the maxillar AC (p?<?0.01) independent of orthodontic treatment. The percentage (%) difference of variability of CT attenuation values changed for both AT and AC in the maxilla after orthodontic treatment, while that changed for only the AT (p?<?0.02), but not for AC, in the mandible (p?>?0.16).Conclusions
The alveolar cortical region of the mandible responded differently to orthodontic treatment compared with other alveolar regions.Clinical relevance
The CBCT-based DBM analysis can be used clinically to assess alveolar bone quality changes induced by orthodontic treatment to improve treatment planning and result evaluation. 相似文献4.
Objectives
The purpose of the present study was to assess the presence and course of the incisive canal (IC) in the mental interforaminal region according to dental status, age, and sex using cone-beam computed tomography (CBCT).Methods
The right and left sides were retrospectively studied in 356 patients (n = 712). Axial, sagittal, cross-sectional, and panoramic images were evaluated, and three-dimensional images were reconstructed and evaluated as necessary. The morphology, course, and length of mandibular ICs and the inner and outer diameters of the canals were measured. The reliability and reproducibility of measurements were examined using the intraclass correlation coefficient and the coefficient of variation.Results
The IC was found on 91 % of images, and its mean length anterior to the mental foramen was approximately 12.4 mm. The mean distance of the IC from the lower mandibular border was 10.5 mm, and its course was closer to the buccal border at the starting point; it deviated lingually through the anterior mandible. Statistically significant differences in the course and localization of the IC were found in edentulous and older patients (p < 0.05).Conclusion
A high proportion of mandibular canals can be detected by CBCT imaging. Clinicians should be careful during implant or bone surgery procedures to avoid possible complications, with special emphasis on patient age and dental status, using this imaging modality that minimizes radiation exposure. 相似文献5.
Patrícia Pereira-Maciel Emerson Tavares-de-Sousa Marcelo-Augusto Oliveira-Sales 《Medicina oral, patología oral y cirugía bucal》2015,20(6):e723-e728
Background
To avoid postoperative injuries in the interforaminal region, presence of the Mandibular Incisive Canal (MIC), its extension and canal positioning in relation to the cortical bone and alveolar process were investigated by cone beam computed tomography (CBCT).Material and Methods
One hundred CBCT examinations obtained by means of the i-CAT CBCT imaging system were analyzed in multiple-plane views (axial, panoramic and cross-sectional) and three-dimensional representations were performed using iCAT CBCT software. The MIC was evaluated for its presence, measurement and proximity to the buccal and lingual plates, alveolar process and inferior border of the mandible.Results
The MIC was visible in all (100%) CBCT images. The mean length of MIC was 9.8 ± 3.8 mm. The distances between the canal and buccal plate, as well as between the canal and lingual plate of the alveolar bone were 4.62 ± 1.41 mm and 6.25 ± 2.03 mm, respectively. The distances from the canal to the alveolar process, and to the inferior border of the mandible were 10.25 ± 2.27 mm and 7.06 ± 2.95 mm, respectively.Conclusions
Due to the high prevalence of MIC, its variation in length and distance up to the cortical bone, suggested that preoperative radiographic evaluation of the MIC must be carried out case-by-case using CBCT, which could clearly show the three-dimensional structure and adjacent structure of the MIC. Key words:Diagnosis, anatomy, cross-sectional, tomography. 相似文献6.
Background
The number of three-dimensional imaging examinations in oral radiology has been constantly growing in the last few years and three-dimensional diagnostics using cone beam computed tomography (CBCT and CT) can be performed in addition to traditional 2-dimensional dental radiography. The indications for CBCT and CT range from oral surgery and implant surgery to conservative dentistry, endodontology and parodontology up to orthodontology and temporomaxillary joint diagnostics.Methods
Before every dental radiography examination, especially using three-dimensional techniques, strict indications must be present. Furthermore, the health benefits have to outweigh the radiation risk and the ALARA principle (as low as reasonable achievable) should be observed in favor of radiation protection. 相似文献7.
Elisabeth Hofmann Matthias Schmid Martin Sedlmair Rosemarie Banckwitz Ursula Hirschfelder Michael Lell 《Clinical oral investigations》2014,18(1):301-311
Objectives
The aim of this study was to evaluate the image quality and dose exposition of different cone-beam computed tomography (CBCT) and low-dose multislice spiral CT (MSCT) scanners.Materials and methods
A human cadaver head was examined with three MSCT and five CBCT scanners. The radiation dose was measured using an Alderson RANDO phantom. Standard protocols were used to obtain the CBCT data. For the MSCT devices, the tube voltage and tube current were modified to obtain acceptable image quality while keeping the radiation dose as low as possible. The image quality of MSCT and CBCT devices was determined by examining the enamel–dentin and dentin–pulp interface and the periodontal ligament space of 22 teeth.Results
Inter- and intra-observer agreement was found for the different groups of raters. CBCT systems were rated superior to MSCT devices in terms of image quality for all dental structures. The differences in image quality among the studied CBCT and MSCT scanner groups did not turn out to be significant but were significant between CBCT and MSCT devices. The organ dose varied considerably between the different CBCT and MSCT devices. The differences concerning the organ dose were notably pronounced in the area of the eye lens.Conclusions
The tested devices exhibited significant differences with respect to the organ dose. The variance was particularly pronounced in the CBCT devices. With a dose exposition equal or lower than the CBCT, the image quality in the MSCT devices was judged to be significantly worse. 相似文献8.
Oliveira-Santos C Capelozza AL Dezzoti MS Fischer CM Poleti ML Rubira-Bullen IR 《Journal of applied oral science : revista FOB》2011,19(3):240-243
The identification of the mandibular canal (MC) is an important prerequisite for
surgical procedures involving the posterior mandible. Cone beam computed tomography
(CBCT) represents an advance in imaging technology, but distinguishing the MC from
surrounding structures may remain a delicate task.
Objectives
The aim of this study was to assess the visibility of the MC in different regions on CBCT cross-sectional images.Material and methods
CBCT cross-sectional images of 58 patients (116 hemi-mandibles) were analyzed, and the visibility of the MC in different regions was assessed.Results
The MC was clearly visible in 53% of the hemi-mandibles. Difficult and very difficult visualizations were registered in 25% and 22% of the hemi-mandibles, respectively. The visibility of the MC on distal regions was superior when compared to regions closer to the mental foramen. No differences were found between edentulous and tooth-bearing areas.Conclusions
The MC presents an overall satisfactory visibility on CBCT cross-sectional images in most cases. However, the discrimination of the canal from its surrounds becomes less obvious towards the mental foramen region when cross-sectional images are individually analyzed. 相似文献9.
Noura A. Alsufyani Michelle L. Noga Manisha Witmans Paul W. Major 《Oral Radiology》2017,33(3):161-169
Objective
To review recent use of three-dimensional (3D) imaging, specifically cone-beam computed tomography (CBCT), in the analysis of the upper airway for diagnosis or treatment outcomes in patients with sleep-disordered breathing (SDB).Types of studies reviewed
Literature review of relevant medical and dental studies utilizing 3D imaging to assess the upper airway.Results
Imaging of the upper airway provided insight into potential areas of obstruction. Accessibility of CBCT to dentists is reflected in several applications of upper airway diagnosis, treatment planning, and different treatment outcomes, as well as association with craniofacial development. However, multiple deficiencies in image acquisition, 3D reconstruction, and analysis are evident.Practical implications
The role of CBCT in the analysis of the upper airway is growing; however, critical limitations remain. An understanding of these limitations, clarification of misconceptions, and improvements in analysis methods are required to ensure proper use and development of CBCT.10.
Introduction
Ten to twelve percent of all cases of maxillary sinusitis derive from odontogenic origin. The purpose of this study was to report the use of cone-beam computed tomography (CBCT) scanning in elucidating dental pathology as an etiology of maxillary sinusitis.Methods
Intraoral periapical radiographs and CBCT scanning were performed in the evaluation of three patients presenting with pain, sinus congestion, or respiratory complaints. In the first case, extractions of impacted third molar and adjacent nonrestorable tooth were performed. In the second two cases, endodontic therapy was done. Radiologic follow-up with CBCT scanning or medical computed tomography scanning was performed 6 to 12 months after dental procedures were performed.Results
All three patients presented with severe sinusitis that resolved after appropriate dental treatment. The first patient also showed marked improvement of chronic bronchitis after completion of dental treatment. In all patients, complete or near total resolution of sinusitis, including eradication of mucous retention cyst, was confirmed by post-treatment CBCT or computed tomography scanning.Conclusions
These cases show the utility of CBCT scanning in evaluating patients presenting with concurrent sinus and dental complaints. In these three patients, maxillary sinusitis of odontogenic origin responded well to the eradication of dental etiology. 相似文献11.
Maxillofacial cone beam computed tomography (CBCT) is one of the most significant advances in dental imaging since rotational panoramic radiography. While the acquisition of CBCT data is technically simple, numerous parameters should be considered so that CBCT imaging is performed appropriately and 'task specific'. This involves an understanding of not only exposure (e.g. geometric and software parameters to minimize patient dose, while sustaining diagnostic image quality) but also image formatting options to maximize image display. CBCT images contain far more detailed information of the maxillofacial region than do panoramic or other 2-D images and necessitate a thorough knowledge of the 3-D anatomy of the region and considerations of variability in the range of the anatomically normal. These principles, procedures and protocols, together with the interpretation of CBCT images form the basis of best practices in maxillofacial CBCT imaging. This communication aims to provide: (1) an overview of the fundamental principles of operation of maxillofacial CBCT technology; (2) an understanding of 'task specific' equipment, image selection and image display modes; and (3) a systematic methodology for sequencing interpretation of CBCT images. 相似文献
12.
Maryam Shahbazian Charlotte Vandewoude Jan Wyatt Reinhilde Jacobs 《Clinical oral investigations》2014,18(1):293-300
Objective
The purpose of this study was to assess whether and how the information obtained by means of cone beam computed tomography (CBCT) on maxillary posterior teeth differs from that obtained by panoramic radiography.Materials and method
From 157 subjects (mean age 48 years, range 19–84 years; 89 females) referred to the oral imaging center, a pair of panoramic and CBCT images was selected for further analysis. Both imaging modalities were analyzed to determine the topographic relationship of maxillary teeth to the sinus floor. Pathologic conditions, apical periodontitis, and presence of soft tissue thickening were also examined with both techniques.Results
CBCT showed an intimate relationship of the first and second molar with the maxillary sinus in 54 and 38 %, respectively. Thirty-nine apical periodontitis lesions causing reactive changes in the maxillary sinus were detected by CBCT, while just six of them were diagnosed with panoramic imaging. A total of 26 teeth with apical extension to the maxillary sinus were detected with CBCT, from which two could be identified with panoramic radiography.Conclusion
This study emphasizes that anatomical and pathological involvement of the maxillary sinus in relation to posterior teeth is considerably high. It is of clinical importance that the 3D nature of CBCT imaging allowed a better assessment of the relationship between the maxillary sinus and posterior root apices compared to the low detection on panoramic radiographs.Clinical relevance
CBCT imaging can be a valuable adjunct in radioanatomical and radiodiagnostic observations in the posterior maxilla. It may better visualize maxillary sinus involvement for posterior upper teeth than panoramic radiography. 相似文献13.
Luciano Teles Gomes Carlos Fernando de Almeida Barros Mourão Cícero Luiz Braga Luiz Fernando Duarte de Almeida Rafael Coutinho de Mello-Machado Mônica Diuana Calasans-Maia 《Oral and maxillofacial surgery》2018,22(4):379-384
Background and objective
To evaluate the prevalence, location, length, diameter, and distances related to the incisive canal (IC) and the need for cone beam computed tomography (CBCT) as a complementary exam prior to surgery in the mental region.Materials and methods
One hundred CBCT images from patients of both genders aged 27 to 73 years were evaluated. At every 3 mm, the diameter (DIAM) of the right and left ICs and their location, their distance to base of the jaw (BIC), the buccal (BAIC) and lingual (LAIC) aspects, and their length were measured.Results
The 100 patients comprised 50 men (50%) and 50 women (50%). The IC was detected in 78 patients, more frequently in women (80%) than in men (76%). Measurements were taken in millimeters. The mean measurements for the two sides and for men and women combined were as follows: BIC?=?10.0, BAIC?=?4.0, LAIC?=?6.2, ICL?=?19.9, and DIAM?=?1.4.Conclusions
The measurements show the need for care from professionals when performing intraosseous surgical procedures in the mental region. The distances between the IC and the references studied must be observed. Thus, CBCT becomes essential for surgical planning in the mental region.Clinical relevance
The mental region of the mandible is considered a safe area to perform surgical procedures such as the placement of osseointegrated implants, orthognathic surgery, and the removal of bone grafts. However, this region includes important neurovascular structures that must be considered or else hemorrhage and neurologic disorders can be experienced.14.
Azin Parsa Norliza Ibrahim Bassam Hassan Paul van der Stelt Daniel Wismeijer 《Oral Radiology》2014,30(2):153-159
Objectives
The aim of this study was to determine the gray value variation at an implant site with different object location within the selected field of view (FOV) in two cone beam computed tomography (CBCT) scanners.Methods
A 1-cm-thick section from the edentulous region of a dry human mandible was scanned by two CBCT scanners: 3D Accuitomo 170 (J. Morita, Kyoto, Japan) and NewTom 5G (QR Verona, Verona, Italy). Five FOVs were used with each CBCT scanner. Within each FOV, the specimen was located at different positions. The scans were converted to DICOM format. Data analysis was performed using 3Diagnosys (ver. 3.1, 3DIEMME, Cantu, Italy) and Geomagic software (Studio 2012, Morrisville, NC). On one of the scans, a probe designating the site for pre-operative implant placement was selected. The inserted virtual implant was transformed on the same region on each CBCT scan by a three-dimensional registration algorithm. The mean voxel gray value of the region around the probe was derived separately from all CBCT scans. The influence of object location within each FOV on variability of voxel gray values was assessed.Results
In both CBCT systems, object location had a significant influence on gray value measurements (F 4,16 = 3.71, p = 0.0255 for Accuitomo and F 4,16 = 9.31, p = 0.0000 for NewTom).Conclusions
Gray level values from CBCT images are influenced by object location within the FOV. 相似文献15.
Caroline Marca Paul M. H. Dummer Susan Bryant Fabiana Vieira Vier-Pelisser Marcus Vinicius Reis Só Vania Fontanella Vinicius D’avila Dutra José Antonio Poli de Figueiredo 《Clinical oral investigations》2013,17(6):1535-1540
Objectives
The aim of this study was to analyze the variations in canal and root cross-sectional area in three-rooted maxillary premolars between high-resolution computed tomography (μCT) and cone beam computed tomography (CBCT).Materials and methods
Sixteen extracted maxillary premolars with three distinct roots and fully formed apices were scanned using μCT and CBCT. Photoshop CS software was used to measure root and canal cross-sectional areas at the most cervical and the most apical points of each root third in images obtained using the two tomographic computed (CT) techniques, and at 30 root sections equidistant from both root ends using μCT images. Canal and root areas were compared between each method using the Student t test for paired samples and 95 % confidence intervals.Results
Images using μCT were sharper than those obtained using CBCT. There were statistically significant differences in mean area measurements of roots and canals between the μCT and CBCT techniques (P?<?0.05). Root and canal areas had similar variations in cross-sectional μCT images and became proportionally smaller in a cervical to apical direction as the cementodentinal junction was approached, from where the area then increased apically.Conclusion
Although variation was similar in the roots and canals under study, CBCT produced poorer image details than μCT.Clinical relevance
Although CBCT is a strong diagnosis tool, it still needs improvement to provide accuracy in details of the root canal system, especially in cases with anatomical variations, such as the three-rooted maxillary premolars. 相似文献16.
Samer G. Hakim Henning Wieker Thomas Trenkle Peter Sieg Jens Konitzer Konstanze Holl-Ulrich Hans-Christian Jacobsen 《Clinical oral investigations》2014,18(3):961-967
Objectives
The objective of this paper is to evaluate the predictability of preoperative tumour bone invasion of the mandible by squamous cell carcinoma of the oral cavity using CT, cone-beam CT and bone scintigraphy with SPECT.Material and methods
Eighty-four patients who had received CT, SPECT or cone-beam computed tomography (CBCT), as well as a further 48 patients who undergone all these investigations for preoperative evaluation of bone invasion were included in the study. A case–control analysis and the receiver operating characteristics were performed. Histological results of bone specimens served as the gold standard for assessment of bone invasion.Results
CBCT and SPECT showed a comparable sensitivity for bone invasion (93 % [CI 0.816–0.972] and 96 % [CI 0.867–0.990], respectively) which was significantly higher than that of CT (63 % [CI 0.488–0.752]). Further, CBCT obtained higher specificity than SPECT (62 % [CI 0.478–0.743] and 48 % [CI 0.342–0.614], respectively), whereas CT showed the best specificity among the investigation methods (81 % [CI 0.677–0.896]).Conclusions
CT scan provides by its high specificity and positive predictive value a precise imaging technique for clinical routine. However, CBCT shows a much higher sensitivity for cortical bone invasion and a better negative predictive value. With a significantly lower exposure dose it can rule out this invasion effectively and prevent overtreatment.Clinical relevance
Considering the high-resolution images delivered by CBCT along with minimized artefacts in the mandible it provides an alternative imaging technique, which could be combined and accomplished with another soft-tissue imaging modality like MRI to obtain optimal hard and soft-tissue visualisation in patients with squamous cell carcinoma of the oral cavity. 相似文献17.
18.
Frederico Sampaio Neves Monikelly Carmo Chagas Nascimento Matheus Lima Oliveira Solange Maria Almeida Frab Norberto Bóscolo 《Oral and maxillofacial surgery》2014,18(4):419-424
Purpose
The objective of this study is to compare the ability of panoramic radiography and cone beam computed tomography (CBCT) in detecting anatomical variations of the mandibular canal and mental foramen.Methods
One hundred twenty-seven preoperative panoramic and CBCT images were evaluated. Two oral and maxillofacial radiologists investigated the presence of bifid mandibular canals and/or additional mental foramina on the right, left, or both sides of the mandible. Intra- and interobserver reliability was determined using Cohen’s kappa coefficient. McNemar’s test compared the prevalence of mandibular anatomical variations between panoramic radiography and CBCT. The significance level was set at 0.05.Results
Additional mental foramen and bifid mandibular canal were detected in 1.2 and 7.4 % of the panoramic radiographs and 7.4 and 9.8 % of the CBCT images, respectively. The incidence of anatomical variations on the mandibular canal was not significantly different between both imaging modalities (P?>?0.05).Conclusions
Although CBCT provides better viewing of anatomical structures, including location, shape, and relationship with the surrounding area, panoramic radiography is a conventional imaging modality that can be used in the study of the bifid mandibular canals. 相似文献19.
Laurence Gaalaas Lisa Henn Philippe R. Gaillard Mansur Ahmad Mohammad Saiful Islam 《Oral Radiology》2014,30(2):179-185
Objective
The purpose of the study was to explore the use of cone beam CT (CBCT) images to calculate fractal values of trabecular bone.Materials and methods
Seventy-nine CBCT scans were used. Seven sites were selected from each scan. These sites were: coronal views of the (1) right and (2) left side of the mandible; coronal views of the (3) right and (4) left maxilla; axially corrected coronal views of the (5) right and (6) left condylar heads through the largest width, and (7) a sagittal section through the second cervical vertebral (C2) body. Fractal values were calculated from a total of 553 images using the box-counting method. These values were categorized and analyzed for site- and gender-specific differences.Result
Fractal values decreased in most of the sites with increasing age. Values in males were generally higher than those in females. Values did not change significantly from right side to left side of the jaw. However, values from the mandible, maxilla, condyle and C2 vertebrae differed significantly from each other, suggesting a site-specific nature of the fractal value (p < 0.001). The lowest and highest fractal values were in the mandible and C2 vertebrae, respectively (1.313 and 1.536, respectively).Conclusion
Fractal values can detect differences in the trabecular bone morphology in different parts of the jaw. Fractal values can potentially be used for objective analysis of the trabecular bone using CBCT images. 相似文献20.