Applications of cone beam computed tomography in dental and oral medicine

Cone beam computed tomography (CBCT) is a radiological technique available since 1998 in dental and oral medicine in which a cylindrical volume is acquired with a conical x-ray beam during one rotation around the head of the patient (cone beam computed tomography, cone beam CT). This technique is increasingly replacing conventional radiological procedures due to the possibility of arbitrary reconstructions and views free of superimposition. CBCT focuses on the display of the bones of the jaw, so that its use concentrates on problems in implantology, before surgical removal of impacted and displaced teeth, in traumatology, and in craniofacial malformations. The objective of this overview was to emphasize the advantages of cone beam computed tomography in the individual disciplines. However, schematization of examinations should be avoided for reasons of radiation protection and for avoiding forensic pressure. The limits of CBCT and thus an indication for computed tomography exist where there is suspicion of bone tumors with soft tissue participation as well as in extensive fractures with suspicion of craniocerebral trauma. In the case of tumors in the soft tissues and of functional temporomandibular joint symptoms, magnetic resonance tomography is preferable to CBCT.     

Is there a role for the use of volumetric cone beam computed tomography in periodontics?

Volumetric computed cone beam tomography offers a number of significant advantages over conventional intraoral and extraoral panoramic radiography, as well as computed tomography. To date, periodontal diagnosis has relied heavily on the assessment of both intraoral radiographs and extraoral panoramic radiographs. With emerging technology in radiology there has been considerable interest in the role that volumetric cone beam computed tomography might play in periodontal diagnostics. This narrative reviews the current evidence and considers whether there is a role for volumetric cone beam computed tomography in periodontics.     

The use of cone beam computed tomography in the management of external cervical resorption lesions

AIM: To report the use of cone beam computed tomography in the assessment of external cervical resorption lesions. SUMMARY: Asymptomatic external cervical resorption lesions were diagnosed radiographically in two patients. Clinical examination in both cases was unremarkable. Cone beam computed tomography scans revealed the true nature of the lesions in three dimensions. The resorption lesion in case 1 was confined predominantly to the buccal aspect of the root, the lesion had not perforated into the root canal. A mucoperiosteal flap was raised to gain access to the lesion, the resorptive lesion was excavated and the defect repaired with glass ionomer cement. In case 2 the cone beam computed tomography scan revealed that the resorptive lesion was more extensive than it appeared radiographically, making the prognosis of reparative treatment very poor. In this case, the patient was advised to have the tooth extracted. KEY LEARNING POINTS: The true extent of external cervical resorption lesions cannot always be estimated from conventional radiographs. Cone beam computed tomography can be a useful diagnostic tool in the management of external cervical resorption lesions.     

Dental cone beam computed tomography: justification for use in planning oral implant placement

Intra‐oral and panoramic radiographs are most frequently used in oral health care. Yet, the inherent nature of jaws and teeth renders three‐dimensional diagnosis essential, especially in relation to oral surgery. Nowadays, this can be accomplished by dental cone beam computed tomography, which provides high‐quality images at low radiation doses and low costs. Nonetheless, the effective dose ranges of cone beam computed tomography machines may easily vary from 10 to 1000 μSv, this being equivalent to two to 200 panoramic radiographs, even for similar presurgical indications. Moreover, the diagnostic image quality varies massively among available machines and parameter settings. Apart from the radiodiagnostic possibilities, dental cone beam computed tomography may offer a vast therapeutic potential, including opportunities for surgical guidance and further prosthetic rehabilitation via computer‐aided design/computer‐aided manufacturing solutions. These additional options may definitely explain part of the success of cone beam computed tomography for oral implant placement. In conclusion, dental cone beam computed tomography imaging could be justified for oral implant‐related diagnosis, planning and transfer to surgical and further prosthetic treatment, but guidelines for justification and cone beam computed tomography optimization remain mandatory.     

Use of cone beam computed tomography in implant dentistry: current concepts,indications and limitations for clinical practice and research

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.     

Comparative evaluation of sagittal condylar guidance obtained from a clinical method and with cone beam computed tomography in dentate individuals

Statement of problemProgramming semiadjustable and fully adjustable articulators involves time-consuming clinical steps which can be avoided if an accurate radiographic method can accurately determine the condylar guidance angles.PurposeThe purpose of this clinical study was to compare the sagittal condylar guidance in dentate individuals as determined by a clinical method, protrusive interocclusal record, and a radiographic method, cone beam computed tomography. If the methods show a correlation, then cone beam computed tomography can be used as a time-saving method of programming an articulator for patients requiring a cone beam computed tomography scan.Material and methodsA total of 40 participants (20 men and 20 women) within the 20 to 40 years age group were enrolled according to the inclusion and exclusion criteria. Cone beam computed tomography scans were obtained, and by using an appropriate software program, the sagittal condylar guidance was measured for both sides. A protrusive interocclusal record was obtained by using polyvinyl siloxane material. The maxillary cast of each participant was mounted on a semiadjustable articulator with a facebow transfer, and the mandibular cast was mounted with a maximum intercuspal record. The protrusive record was then transferred to the articulator for programming.ResultsThe right and left sagittal condylar guidance values obtained from both the protrusive interocclusal record and cone beam computed tomography method were comparable, with no significant differences (P>.05). The difference in condylar inclination values for both sexes obtained from both methods for both sides were not statistically different (P>.05). With increasing age, condylar inclination values obtained from both methods tended to decrease. The values for sagittal condylar guidance obtained from both methods (protrusive interocclusal record and cone beam computed tomography) were comparable and correlated.ConclusionsCone beam computed tomography measurement involves stable bony landmarks and can be standardized, whereas clinical methods are time consuming and can provide inaccurate results because of the instability of the materials used to register the maxillomandibular relationship. Thus, cone beam computed tomography can be used to obtain the sagittal horizontal guidance for programming semiadjustable and fully adjustable articulators for patients requiring a cone beam computed tomography scan.     

Implagraphy牙颌面锥形束CT与多层螺旋CT的图像质量对比研究

目的：比较牙颌面锥形束CT与多层螺旋CT的图像质量。方法：分别使用牙颌面锥形束CT和多层螺旋CT对实验模体进行扫描，比较两者显示牙、牙周组织、颌面骨解剖结构的差异。结果：牙颌面锥形束CT图像质量，优于多层螺旋CT。结论：牙颌面锥形束CT因其优秀的图像质量，更加适合口腔临床的需要。     

Computer-based implant planning involving a prefabricated custom tray with alumina landmark structures

The purpose of this technical report was to describe a method for the fabrication of a custom tray with landmark structures to coordinate cone beam computed tomography and scan data for use in guided implant surgery in patients with numerous artifact-causing metal prostheses. The fabricated custom tray can be used to coordinate cone beam computed tomography data and scan data from the dentition, as well as to fabricate the prostheses.     

Three-dimensional evaluation of the posterior airway space: differences in computed tomography and cone beam computed tomography

Clinical Oral Investigations - Obstructive sleep apnea syndrome (OSAS) becomes increasingly important. For diagnosis and surgery, computed tomography (CT), and cone beam computed tomography (CB-CT)...     

Cone beam computed tomography in the diagnosis of dental disease

Conventional radiographs provide important information for dental disease diagnosis. However, they represent 2-D images of 3-D objects with significant structure superimposition and unpredictable magnification. Cone beam computed tomography, however, allows true 3-D visualization of the dentoalveolar structures, avoiding major limitations of conventional radiographs. Cone beam computed tomography images offer great advantages in disease detection for selected patients. The authors discuss cone beam computed tomography applications in dental disease diagnosis, reviewing the pertinent literature when available.     

Gray value measurement for the evaluation of local alveolar bone density around impacted maxillary canine teeth using cone beam computed tomography

Background To investigate whether any relationship between local alveolar bone density and maxillary canine impaction using gray values from cone beam computed tomography.Material and Methods The cone beam computed tomography images of 151 patients were retrospectively evaluated. Maxillary canine was defined as an impacted tooth when root formation was complete and the patient’s age older than 13 or the other side of the maxillary canine has completely erupted. Similarly, complete eruption was defined as the tooth in its expected occlusion and position. Using the cone beam computed tomography software, the region of interest which was 5 mm2 in area, was placed in the trabecular bone on cross sectional cone beam computed tomography images and the gray value measurements were recorded. After measuring the gray values of all the teeth, the images were grouped according to the field of view size. Comparison of the gray values of impacted and non-impacted teeth was made between images with the same field of view size.Results A total of 151 patients, 101 (66.9%) female and 50 (33.1%) male, were included in the study. The mean age of the patients was 24.94 ±13.9. In images with a 40X40 field of view, the gray values of the impacted canine teeth were higher than the gray values of the non-impacted ones and statistically significant difference was found between them (p=0.003). However no statistically significant difference was found between the gray values of impacted and non-impacted canine teeth in 60x60 and 100x50 field of view (p=0.197, p=0.170, respectively).Conclusions We suggest using the smallest field of view size when evaluating bone density using gray values from cone beam computed tomography images and we support the idea that the local increased bone density may influence on impaction. Key words:Cone-beam computed tomography, tooth, impacted, bone density, maxilla, image processing, computer-assisted.     

Cone beam computed tomography in craniofacial imaging

Cone beam computed tomography (CT) has the potential to reduce the size and cost of CT scanners. Because this emerging technology produces images with isotropic submillimeter spatial resolution, it is ideally suited for dedicated dentomaxillofacial CT scanning. When combined with application-specific software tools, cone beam computed tomography can provide dentomaxillofacial practitioners with a complete solution for performing specific diagnostic and surgical tasks, such as dental implant planning. In this paper, we provide a brief overview of cone beam scanning technology and compare it with the fan beam scanning used in conventional CT scanners. We introduce 'DentoCAT', a relatively small, low-cost cone beam CT scanner dedicated for dentomaxillofacial imaging developed at Xoran Technologies. We present images generated by the DentoCAT scanner and provide an assessment of its performance in terms of spatial resolution and effective radiation dose. Finally, we illustrate the clinical utility of the scanner by presenting the results we have obtained to date using the DentoCAT scanner in conjunction with an implant planning software tool.     

Computer-assisted reconstruction of orbital floor based on cone beam tomography

We used a navigation system for computer-assisted preoperative planning based on cone beam tomography with virtual reconstruction to obtain symmetry of the orbit and intraoperative control of virtual contours. In operations for reconstruction of the orbital floor this technique offers a reliable intraoperative control in an area of limited exposure and visibility. There was no significant difference in visualisation of anatomical structures between the cone beam tomographic digital imaging and communication (DICOM) data and computed tomographic data. Cone beam tomography seems to be suitable for computer-assisted planning in the management of orbital trauma with reduced costs and less radiation.     

下颌第二前磨牙牛牙症伴C型根管的显微治疗一例

牛牙症、C型根管在下颌第二前磨牙的发生率均极低.本文报道1例罕见下颌第二前磨牙牛牙症伴C型根管病例,展示锥形束CT影像学分析和显微根管技术在该病例诊治中的联合应用,为该特殊类型根管的临床治疗提供新思路.     

Comparative dosimetry of dental cone beam computed tomography, panoramic radiography, and multislice computed tomography

Objectives  

The aim of this study was to compare the effective organ doses from cone beam computed tomography (CBCT), multislice computed tomography (MSCT), and panoramic radiography.     

The use of cone beam computed tomography in the management of isolated orbital floor fractures

Isolated fractures of the orbital floor are diagnosed by a combination of clinical and radiographic findings. Computed tomography is considered the imaging method of choice. We describe the use of cone beam computed tomography for use in isolated fractures of the orbital floor. This shows defects in the orbital floor but with a lower dose of radiation than conventional computed tomography.     

State of the art of fusion of computed tomography data and optical 3D images

When three-dimensional imaging is necessary in dentistry, oral surgery or maxillofacial surgery, conventional computed tomography or cone beam computed tomography is chosen regularly. However, there are two obvious drawbacks. Metallic restorations lead to pronounced streak artefacts in conventional computed tomography. Moreover, the resolution of both conventional computed tomography and cone beam computed tomography is limited to 0.3 mm. This resolution is not sufficient for the fabrication of dental restorations. In order to improve the quality of the two different computed tomography techniques and to eliminate streak artefacts, fusion with optical 3D images can be considered. The resolution of optical 3D images can reach the range of some microms depending on the calibration of the sensor. Metal artefacts do not occur. The fusion of computed tomography images without artefacts and optical 3D images leads to a mean deviation of corresponding points for the two imaging techniques of 0.1262 +/- 0.0301 mm. When computed tomography images with metal artefacts are used, the deviation increases up to 0.2671 +/- 0.0580 mm. The accuracy of image fusion is significantly reduced by metal artefacts (p < 0.0005). When image fusion of computed tomography and optical 3D images is used in clinical studies, the mean deviation of corresponding points for the two imaging techniques for mandible and maxilla is 0.66 +/- 0.49 mm and 0.56 +/- 0.48 mm, respectively. The available data on image fusion show that the quality of computed tomography data without streak artefacts can be significantly improved by registration with optical 3D images. The precision of the fused images exceeds the resolution of the original computed tomography. When streak artefacts are present, image fusion makes it possible to increase the quality of the data to the level of the original resolution of computed tomography without artefacts.     

Cone beam computed tomography (CBCT) for diagnosis and treatment planning in periodontology: systematic review update

Clinical Oral Investigations - To update the findings of a systematic review from the year 2016 on the evidence for the accuracy and potential benefits of cone beam computed tomography (CBCT) in...     

Radioanatomic study of maxillary sinus palatal process pneumatization

Oral Radiology - To perform a detailed analysis of palatal process pneumatization (PPP) on cone beam computed tomography (CBCT) images. This study consisted of 376 maxillary sinuses of 188 patients...     

Comparative evaluation of bone microstructure in alveolar cleft repair by cone beam CT: influence of different autologous donor sites and additional application of β-tricalcium phosphate

Clinical Oral Investigations - This study used cone beam computed tomography (CBCT) images to comparatively evaluate the three-dimensional microstructural features of reconstructed bone bridge...