Showing 14 results for Computed Tomography
M. Panjnoush, A. Shokri, M. Hosseini Pouya, M. Deevband,
Volume 22, Issue 3 (12-2009)
Abstract
Background and Aim: The objective of this study was to measure and compare the tissue absorbed dose in thyroid gland, salivary glands, eye and skin in maxillofacial imaging with panoramic, conventional linear tomography, cone beam computed tomography (CBCT) and computed tomography (CT).
Materials and Methods: Thermoluminescent dosimeters (TLD) were implanted in 14 sites of RANDO phantom to measure average tissue absorbed dose in thyroid gland, parotid glands, submandibular glands, sublingual gland, lenses and buccal skin. The Promax (PLANMECA, Helsinki, Finland) unit was selected for Panoramic, conventional linear tomography and cone beam computed tomography examinations and spiral Hispeed/Fxi (General Electric,USA) was selected for CT examination. The average tissue absorbed doses were used for the calculation of the equivalent and effective doses in each organ.
Results: The average absorbed dose for Panoramic ranged from 0.038 mGY (Buccal skin) to 0.308 mGY (submandibular gland), linear tomography ranged from 0.048 mGY (Lens) to 0.510 mGY (submandibular gland),CBCT ranged from 0.322 mGY (thyroid glad) to 1.144 mGY (Parotid gland) and in CT ranged from 2.495 mGY (sublingual gland) to 3.424 mGY (submandibular gland). Total effective dose in CBCT is 5 times greater than Panoramic and 4 times greater than linear tomography, and in CT, 30 and 22 times greater than Panoramic and linear tomography, respectively. Total effective dose in CT is 6 times greater than CBCT.
Conclusion: For obtaining 3-dimensional (3D) information in maxillofacial region, CBCT delivers the lower dose than CT, and should be preferred over a medical CT imaging. Furthermore, during maxillofacial imaging, salivary glands receive the highest dose of radiation.
A. Eskandarlo, R. Bardal, M. Dehghani,
Volume 24, Issue 1 (3-2011)
Abstract
Background and Aims: Cone beam computed tomography (CBCT) produces high-quality data about diagnosis and periodontal treatment. To date, there is not enough research regarding periodontal bone measurement using CBCT. The aim of this study was to compare the accuracy of CBCT in measuring periodontal defects to that of intraoral radiography and probing methods.
Materials and Methods: Two-hundred and eighteen artificial osseous defects (buccal and lingual infrabony, interproximal, horizontal, crater, dehiscence and fenestration defects) were created on 13 mandibles of dry skulls. The mandibles were put into a plexiglass box full of water to simulate soft tissue. CBCT images, radiographic images taken with parallel technique and direct measurements using a WHO periodontal probe were recorded and compared to a standard reference (digital caliper). Inter and intra observe consistencies were assessed using Intra class correlation coefficient and pearson correlation.
Results: Inter and intra observer consistencies were high for CBCT and probing methods (ICC- Intra class correlation coefficient>88%), but moderate for intraoral radiography (ICC-Intra class correlation coefficient > 54%). There were not any significant differences between observers for all techniques (P>0/05). According to paired T-test analysis, mean difference for CBCT technique (0.01 mm) was lower than that for probing (0.04 mm) and radiography (0.62 mm). CBCT was able to measure all kinds of lesions, but radiography could not measure defects in the buccal and lingual sites.
Conclusion: All three modalities are useful for identifying periodontal defects. Compared to probing and radiography, the CBCT technique has the most accuracy in measuring periodontal defects.
Horie Fakhar Bashizade, Neda Molaei, Ali Teimoorinezhad,
Volume 26, Issue 1 (3-2013)
Abstract
Background and Aims: The Panoramic radiography is one of the routine techniques in implant imaging. Although there are some limitations with this technique, panoramic radiography is radiographic choice for basic evaluation for implant treatment. Many studies have been designed to determine magnification in panoramic images but most of them were performed on dry skulls or radiographic phantoms. In recent studies CT or CBCT are used as gold standard. The aim of this study was to determine vertical magnification of panoramic images using renovated CT sections in anterior and posterior regions of both jaws.
Materials and Methods: 30 panoramic radiographs (Planmeca EC or CC Proline) were selected from patients of implant department and Particular anatomic landmarks were selected in those images. Vertical dimensions of these landmarks were measured in both panoramic and renovated cross sectional CT images by a digital caliper and vertical magnification was calculated as the ratio of image dimensions to the real dimensions.
Results: The mean vertical magnification of panoramic radiographs in anterior and posterior maxillae were 1.22±0.02 and 1.16±0.02, respectively. The mean vertical magnification of panoramic radiograph in anterior and posterior mandible were 1.20±0.02 and 1.13±0.02, respectively. The differences between magnification in mandible and maxillae were significant (P<0.001). The differences between magnification in anterior and posterior regions of both jaws were not significant (P=0.11).
Conclusion: Vertical magnification of panoramic images (Planmeca EC or CC Proline) in different regions in both jaws were between 1.13 to 1.22.
Amin Sobhani Mohhsen, Hasan Razmi, Mona Sadegh,
Volume 26, Issue 3 (8-2013)
Abstract
Background and Aims: Successful root canal therapy requires knowledge of tooth anatomy and root canal morphology. For permanent mandibular premolars, great variety in size, shape and number of roots and root fusion expression has been reported in the literature. There is a wide variety of methods used in studies for evaluating the root canal morphology. One of these methods is Cone-beam Computed tomography (CBCT) that reduces the limitations of two-dimensional X-ray imaging, with less exposure in comparison with other 3D radiographies. Thus, this study was designed to evaluate the differences in the root and canal morphology of permanent mandibular premolars in an Iranian population by means of CBCT images.
Materials and Methods: We searched a database of CBCT scans and evaluated 400 (20-60 years old) patients who met the inclusion criteria and teeth in this images (CBCT) were evaluated in three dimensions (Axial, Coronal and Sagital). Tooth length, number of roots, number of canals, canal type, root curvature and the effect of gender on any of the items mentioned were evaluated. Data were analyzed using T-test.
Results: The average length of the first premolar of mandibular was 22.27 mm and second premolar was 22.28 mm. 98.4% of the first premolar and 98.2% of the second premolar were single root., and 87.3% and 93.1% were single channel. The incidence of number of canals based on vertochy divisions were:type 1: 90.7% and 90.8%, type 0: 2.2% and 2.8%, type 4: 3.3% and 3.1%, type 6: 1.4% and 2.1% and type 3: 2.5% and 1.5% respectively. In any case, there was no significant difference between males and females (P<0.001).
Conclusion: Results indicate that dentists can obtain valuable information about the anatomy and morphology of the root canals using CBCT.
Mehrdad Panjnoosh, Farnoosh Taghavi, Ahmad Reza Shamshiri,
Volume 27, Issue 3 (9-2014)
Abstract
Background and Aims: There is a risk of nerve injury during the extraction of the impacted third molars, in cases with proximity of the inferior alveolar nerve and this tooth. The aim of this study was to evaluate the effect of different various factors on the degree of vulnerability using CBCT (Cone Beam Computed Tomography) imaging technique.
Materials and Methods: CBCT images of 191 patients referred for the exact assessment of the relationship between the mandibular canal and impacted mandibular third molars were selected. The position of these anatomical structures was evaluated at their contact point. The possible effect of gender, impaction form of the third molars, anatomical relationship between the third molars and the mandibular canal and the age differences were studied. Data were analyzed using Chi-square and Student’s t-test.
Results: There was a close relationship between the mandibular canal and impacted third molars in 81.7% of the patients. The contacts were shown to be significantly higher in females than males (P=0.01) and in the cases with the lingually position of the third molar and the mandibular canal (P<0.001). However, the age and impaction form of the teeth did not have a significant influence (P>0.05).
Conclusion: The risk of nerve damage or exposure is increased in females and lingual position of the mandibular canal to the third molar in cases with higher proximity between these 2 structures in panoramic radiographs using CBCT images. Therefore, the surgeon must pay enough attention in these cases of third molar extraction.
Mahdi Niknami, Maryam Mostafavi, Elham Romoozi, Hesam Mikaeili Xiavi,
Volume 28, Issue 4 (1-2016)
Abstract
Background and Aims: Considering importance of recognizing the position of incisive canal before inserting intraosseous implants and bone harvesting from the symphysis and to preventing from adverse effects after these surgeries, using appropriate imaging method is essential and necessary. Due to the high accuracy measurement and high quality of CBCT and also low received dose to patient ̦ the aim of this study was to evaluate and recognize the position of incisive canal using cone beam computed tomography (CBCT).
Materials and Methods: In this study, good quality CBCT mandible image of 60 patients including 32 women and 28 men with average ages of 41.3±2.5 were observed for diagnosing and recognizing the position of mandibular incisive canal using three observers separately. Data were statistically analyzed using SPSS software (version 20.0 for Windows, Chicago, IL, USA) and Chi-square and Fisher's exact tests.
Results: Horizontal and vertical assessment was independent from the sex of patients. The incisive canal was recognizable in 89.8 percent of specimens. In vertical dimension, in 57.5 percent of specimens the canal was observed in the inferior one third and in 32.25 percent in the medial one third. In horizontal dimension, in 14.75 percent of specimens the canal was observed in the buccal one third, 52.75 percent in the medial one third and 22.25 percent in the lingual one third.
Conclusion: The quality of CBCT imaging and its accuracy and resolution can play an important role in the differentiation and determination of the position of incisive canal.
Nasrollah Jabbari, Seyyed Reza Mousavi, Kamal Firoozi,
Volume 28, Issue 4 (1-2016)
Abstract
Background and Aims: With the increasing use of CT (Computed Tomoghraphy) scans in dentistry especially in the implantology, there may be significant increases in the radiation exposure and its risk. During the last year’s ConeBeam Computed Tomoghraphy (CBCT) has been introduced as an imaging modality for dentistry. The aim of this review article was to present comprehensive information have been published, regarding the radiation dose and image quality of Conventional Multislice Computed Tomography (MSCT), Cone-Beam CT (CBCT) and periapical radiography in dentistry imaging.
Materials and Methods: A review of the literature was carried out in PubMed, Google Scholar, Science Direct and Scopus database using key words (CBCT, MSCT, periapical radiography, radiation dose of dentistry and image quality). These searches were limited to the articles published between the years of 1993 to 2015.
Conclusion: In comparison to MSCT, CBCT had a short scanning times and lower radiation dose, but in comparison to periapical radiography, CBCT had higher radiation dose. In contrast, CBCT with flat panel detector had higher spatial resolution to MSCT. The periapical radiography also had a good image contrast and relatively high resolution. Generally, CBCT was suitable for hard tissue imaging and MSCT was preferred for soft tissue imaging.
Farzaneh Mosavat, Hoorieh Bashizadeh Fakhar, Mohammad Javad Kharrazi Fard, Fatemeh Malekpour Estalaki,
Volume 32, Issue 2 (10-2019)
Abstract
Background and Aims: Accurate diagnosis of vertical root fracture (VRF) is a fundamental importance in endodontics. Because of poor prognosis of VRF, digital radiographs with two horizontal angles have limitations in VRF detection. Also, Gutta-percha can produce artifacts that impair CBCT scan accuracy. The aim of this study was to compare accuracy of CBCT and digital radiography system in vertical root fracture in endodentically treated teeth.
Materials and Methods: In this study, 60 endodentically treated single teeth were selected and randomly coded. The teeth were divided into two groups: 30 with induced root fracture and 30 with no fracture. CBCT scan and digital radiographs with two horizontal angles with a difference of fifteen degrees for all teeth were performed. Two observers assessed the CBCT images and digital radiographies for presence of VRF. The statistical analysis used in this study was Weighted Kappa.
Results: CBCT had the highest sensivity (75.8) and specificity (90). Digital radiography with 68.3 sensitivity and 79.1 specificity were not as efficient as CBCT (P<0.05).
Conclusion: According to this study, the accuracy of CBCT seems to be higher than that of digital radiography in detecting VRF and provides the most reliable data in comparison of digital radiography.
Sara Mogharrabi, Asadallah Ahmadzadeh, Safoura Ghodsi, Farzad Bazmi, Sara Valizadeh,
Volume 33, Issue 1 (7-2020)
Abstract
Background and Aims: Immediate implant placement following tooth extraction is a treatment with many advantages. Alveolar bone preservation after immediate implant, need minimum of 2 mm thickness in buccal bone plate. The aim of this study was to evaluate the thickness of buccal cortical bone of maxillary premolars by Cone Beam Computational Tomography (CBCT) technique.
Materials and Methods: In this descriptive epidemiological study, Cone Beam Computed Tomography image was obtained from 29 patients (male and female) referred to the radiology department of Jundi Shapoor dental school of Ahvaz from 1393 (Mehr) to 1394 (Shahrivar) for implant insertion insertion. The thickness of buccal cortical bone was measured in 3 and 5 mm apical to the CEJ and root apex, perpendicular to the longitudinal axis. All the measurements were done by two oral and maxillofacial radiologists, separately. Data were analyzed by SPSS22 software, using descriptive statistics, and T-test.
Results: The thickness of buccal cortical bone in second premolar was significantly more than 1 mm (P=0.001), but in first premolar, the thickness was close to 1 mm with a non-significant difference (P=0.29).
Conclusion: The results of this study showed that immediate implant insertion could be done in the maxillary second premolar area with more predictability compared to the first premolar area.
Amineh Ghaznavy, Ahmad Reza Talaeipour, Mehdi Vatanpour, Amir Abbas Moshari,
Volume 33, Issue 4 (1-2021)
Abstract
Background and Aims: Pulpal exposures originated from the external cervical root resorptions have major effects on the treatment and prognosis. Therefore, the aim of this study was performed to compare the two different imaging systems-digital radiography with PSP (Photostimulable Phosphor) sensor in three horizontal different views and CBCT (cone beam computed tomography) images to assess the pulpal exposure in simulated cavity of external cervical root resorptions that was performed in 1398 in the School of Dentistry of Azad University.
Materials and Methods: 40 intact maxilla anterior teeth with straight roots were included. Teeth were randomly divided to two groups (20 teeth with and 20 without pulpal exposures). Each sample was assessed using PSP digital radiography (in 3 horizontal angles) and CBCT image system, to detect the presence of pulpal exposures. False negative and false positive results in 2 imaging procedures were judged with ratio test.
Results: The results showed in CBCT (P.P.V=85.7%) and (N.P.V=89.5%), and in digital intraoral radiography (P.P.V=80%) and (N.P.V=80%) in proximal defects. Ratio test showed that there were no significant differences in the proximal defects (P<0.4).
Conclusion: The results showed that there were no significant differences in detection of exposure in the proximal surfaces between two imaging systems.
Seyed Ramin Nourbakhsh, Hamideh Yosefpour, Freshteh Osmani,
Volume 34, Issue 0 (5-2021)
Abstract
Background and Aims: In impacted third molar surgery, panoramic radiography is a preliminary technique for assessing the consequences associated with inferior alveolar nerve injury. However, this technique cannot provide enough information to determine the true risk in all cases. The aim of this study was to compare the accuracy of panoramic and CBCT radiographs in evaluating the relationship between the mandibular impacted third molars and the inferior alveolar nerve.
Materials and Methods: In this cross-sectional study, the relationship between mandibular third molar and inferior alveolar nerve in 15 patients referred to the oral and maxillofacial radiology department of Birjand dental school including 20 mandibular third molars were evaluated using two panoramic and CBCT radiographs. Data were analyzed using descriptive statistics and chi-square test and sensitivity analysis in SPSS22.
Results: In the evaluation of the teeth using panoramic radiography, the highest frequency was related to root darkening (65%) and root deflection (65%), and the lowest frequency was related to root narrowing (20%) and canal deviation (5%). The highest sensitivity of panoramic criteria was related to the root darkening with 100% sensitivity and the lowest sensitivity was related to the canal deviation with 17% sensitivity. On the other hand, the highest specificity of panoramic criteria between the mandibular third molars with the inferior alveolar nervewas was related to the two criteria of bifid apex and canal deviation with 100% specificity. The lowest specificity was related to the root deflection with 21% of specificity.
Conclusion: According to the results of this study, the probability of observing relationship between the mandibular third molars with the inferior alveolar nerve in CBCT radiography was very high.
Marzie Mazhari, Ali Habibikia, Ali Badfar, Mehdi Sabaghian, Arash Dabbaghi, Fattaneh Ghorbani Javadpour,
Volume 35, Issue 0 (5-2022)
Abstract
Background and Aims: By using the image processing capability in Cone-Beam Computed Tomography (CBCT), obtained information can be improved. The aim of the present study was to investigate the effect of sharpen image processing filter in determining the external resorption of the root apical region in single-rooted teeth due to the proximity of the impacted tooth using CBCT.
Materials and Methods: In this laboratory study, the lateral surfaces of the apical region of the root of 40 healthy extracted teeth were artificially cut by bur and the teeth were randomly divided into four groups: control, low, moderate, and high resorption. After preparing CBCT of the teeth, the samples were then processed with and without an image sharpening processing filter and examined by two observers. The results of this study were analyzed by SPSS22 and Medcalc Statistical Software version 14. The significance level was considered P≤0.05 for all the statistical tests.
Results: Specificity (100%) and sensitivity (66%>) were either complete or very high for both modes without and with the sharpen filter. The overall accuracy (0.83>) was high in both cases and no significant difference was observed between the two overall accuracies (P>0.05). Statistical analysis of both image observations by two observers showed that the overall sensitivity and accuracy in the medium and high resorption groups was much higher than the low resorption group, but the specificity in all groups was 100%.
Conclusion: The results showed that the images with a sharpening filter did not increase the detection power compared to the unfiltered images. However, as no loss of accuracy was observed with this filter, it could be used as a processing filter.
Arash Sarrafzadeh, Maryam Mohebiniya, Soheila Jadidi,
Volume 36, Issue 0 (5-2023)
Abstract
Background and Aims: The incisive canal cyst also known as nasopalatine duct cyst (NPDC) is the most common developmental non odontogenic cyst and it is usually asymptomatic with a well corticated round, ovoid or in some cases unique heart shaped radiolucent radiographic finding. Its accurate diagnosis from odontogenic cysts, odontogenic tumor, and benign non-odontogenic tumors using clinical and radiographic findings leads to eradication of pathologic condition with minimum residual defects and patient discomfort. In this case report, the clinical and radiographic findings of a 60-year-old female with the chief complaint of swelling was reviewed. There were typical histologic and radiographic findings related to nasopalatine duct cyst. The surgical management is explained. Follow up visit showed satisfactory healing and no dehiscence. It could be suggested that heart shaped radiographic finding in 3-D reconstructed image in the maxillary midline would be a good predictor for NPDC.
Narges Farhad Mollashahi, Eshagh Ali Saberi, Behnam Rousta, Seyed Mohammad Javad Aslani, Farnaz Faramarzian,
Volume 36, Issue 0 (5-2023)
Abstract
Background and Aims: Guided endodontics is a new technique that is now evolving. It is used in many treatments, especially in access cavity preparation and locating root canals in teeth with pulp canal obliteration (PCO), microsurgical endodontics, and fiber post removal in retreatments. In addition, this technique is independent of operator experience, requires less treatment time for the patient, and is more precise and safer than conventional endodontics. This technique involves the use of cone beam computed tomography imaging (CBCT), tooth surface scanning, and special software to provide guidance for performing endodontic treatment in a fast, safe, and minimally invasive manner. This review article aims to introduce guided endodontics and to describe its technique, advantages, and limitations.
