scholarly journals Is it possible to estimate volume of bone defects formed on dry sheep mandibles more practically by secondarily reconstructing section thickness of cone beam computed tomography images?

2020 ◽  
pp. 20200400
Author(s):  
Alaettin Koç ◽  
Sema Kaya
Keyword(s):  
Computed Tomography ◽  
Reference Values ◽  
Cone Beam Computed Tomography ◽  
Bone Defects ◽  
Volume Estimation ◽  
Cone Beam ◽  
Section Thickness ◽  
Segmentation Method ◽  
Semiautomatic Segmentation ◽  
The Mean

Objectives: The purpose of this study was to evaluate the effect of section thickness on volume estimations of bone defects scanned using cone beam computed tomography (CBCT). Methods: 25 bone defects were prepared on sheep mandibles and scanned using a KaVo 3D eXam (KaVo Dental, Biberach, Germany) CBCT device. Section thickness of images were reconstructed at 0.25, 0.5, and 0.75 mm to estimate the volume of these defects using the semiautomatic segmentation method. The volume averages obtained using microcomputed tomography and Archimedes’ method served as reference values. The estimated volumes at each section thickness were compared with the actual volumes using the Friedman test. The accuracy of volume estimation was determined by the percentage error with respect to the reference values, and the mean absolute error (MAE) was calculated. Results: Volumetric values of bone defects obtained with CBCT at section thicknesses up to 0.5 mm were compatible with the actual volumes (p > 0.05). The percentage errors at section thicknesses of 0.25, 0.5, and 0.75 mm were −5.4%, −7.3%, and −13.1%, respectively. The mean absolute errors were 13.6 mm3, 15.7 mm3, and 18.2 mm3, respectively. Conclusions: The section thickness values of CBCT images can be increased to a reasonable level to obtain accurate volume estimation results and save time. The semiautomatic segmentation method can be used reliably for volume estimations of bone defects.

scholarly journals A volumetric study of mandibular condyles in orthognathic patients by semiautomatic segmentation

2021 ◽  
Author(s):  
Max-Philipp Lentzen ◽  
Maximilian Riekert ◽  
Johannes Buller ◽  
Andrea Grandoch ◽  
Matthias Zirk ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Cone Beam Computed Tomography ◽  
Volumetric Analysis ◽  
Cone Beam ◽  
Bivariate Analysis ◽  
Semiautomatic Segmentation ◽  
Computed Tomography Images ◽  
Precise Knowledge ◽  
The Mean ◽  
The Right

Abstract Purpose This study was conducted to elucidate volumetric data of mandibular condyles of orthognathic patients by analyzing cone beam computed tomography images based upon semiautomatic segmentation. Methods Cone beam computed tomography images of 87 patients with malocclusions were analyzed in this retrospective study. Patients were between 17 and 53 years old and diagnosed with Angle class I, II, or III malocclusion. By using the validated open-source software “ITK-SNAP,” the volumetric measurements of 174 mandibular condyles were performed. Volumetric analysis was performed according to intra-subject side differences by paired Student t test. In accordance to inter-subject side, gender, age and type of malocclusion differences bivariate analysis and ANOVA were applied. Results The mean volume for the right condyle was 1.378 ± 0.447 cm3, with a maximum of 2.379 cm3 and a minimum of 0.121 cm3. The mean volume for the left side was 1.435 ± 0.474 cm3, with a maximum of 3.264 cm3 and a minimum of 0.109 cm3. Bivariate analysis indicated a highly significant inter-subject difference between the volume of the left and right mandibular condyles (p < 0.01). Females had a significantly smaller condyle volume than males (p < 0.05 left condyle; p < 0.01 right condyle). Conclusion The fact that shape and volume of mandibular condyles show a high susceptibility to pathological alterations and particularly malocclusions makes a precise knowledge about volumetric changes indispensable. Our results show that significant inter-subject differences in condyle volume could be found with respect to the side and gender. Larger volumes could be assessed for the left condyle and for male patients.

scholarly journals Comparison of the different voxel sizes in the estimation of peri-implant fenestration defects using cone beam computed tomography: an ex vivo study

2020 ◽  
Vol 6 (1) ◽  
Author(s):  
Mehmet Hakan Kurt ◽  
Nilsun Bağış ◽  
Cengiz Evli ◽  
Cemal Atakan ◽  
Kaan Orhan
Keyword(s):  
Computed Tomography ◽  
Cone Beam Computed Tomography ◽  
Ex Vivo ◽  
Statistical Significance ◽  
Area Under The Curve ◽  
Titanium Implant ◽  
Bone Defects ◽  
Titanium Implants ◽  
Cone Beam ◽  
Voxel Size

Abstract Background To examine the influence of voxel sizes to detect of peri-implant fenestration defects on cone beam computed tomography (CBCT) images. Materials and methods This study performed with three sheep heads both maxilla and mandible and two types of dental implant type 1 zirconium implant (Zr40) (n = 6) and type 2 titanium implant (Ti22) (n = 10). A total of 14 peri-implant fenestrations (8 buccal surfaces, 6 palatal/lingual surface) were created while 18 surfaces (8 buccal, 10 palatal/lingual) were free of fenestrations. Three observers have evaluated the images of fenestration at each site. Images obtained with 0.75 mm3, 0.100 mm3, 0.150 mm3, 0.200 mm3, and 0.400 mm3 voxel sizes. For intra- and inter-observer agreements for each voxel size, Kappa coefficients were calculated. Results Intra- and inter-observer kappa values were the highest for 0.150 mm3, and the lowest in 0.75 mm3 and 0.400 mm3 voxel sizes for all types of implants. The highest area under the curve (AUC) values were found higher for the scan mode of 0.150 mm3, whereas lower AUC values were found for the voxel size for 0.400 mm3. Titanium implants had higher AUC values than zirconium with the statistical significance for all voxel sizes (p ≤ 0.05). Conclusion A voxel size of 0.150 mm3 can be used to detect peri-implant fenestration bone defects. CBCT is the most reliable diagnostic tool for peri-implant fenestration bone defects.

scholarly journals Intraoperative cone beam computed tomography for detecting residual stones in percutaneous nephrolithotomy: a feasibility study

Urolithiasis ◽  
2021 ◽  
Author(s):  
R. A. Kingma ◽  
M. J. H. Voskamp ◽  
B. H. J. Doornweerd ◽  
I. J. de Jong ◽  
S. Roemeling
Keyword(s):  
Computed Tomography ◽  
Percutaneous Nephrolithotomy ◽  
Cone Beam Computed Tomography ◽  
University Hospital ◽  
Cone Beam ◽  
Cross Sectional ◽  
The Mean ◽  
Residual Stones ◽  
Residual Fragments

AbstractCone beam computed tomography (CBCT) provides multiplanar cross-sectional imaging and three-dimensional reconstructions and can be used intraoperatively in a hybrid operating room. In this study, we investigated the feasibility of using a CBCT-scanner for detecting residual stones during percutaneous nephrolithotomy (PCNL). Intraoperative CBCT-scans were made during PCNL procedures from November 2018 until March 2019 in a university hospital. At the point where the urologist would have otherwise ended the procedure, a CBCT-scan was made to image any residual fragments that could not be detected by either nephroscopy or conventional C-arm fluoroscopy. Residual fragments that were visualized on the CBCT-scan were attempted to be extracted additionally. To evaluate the effect of this additional extraction, each CBCT-scan was compared with a regular follow-up CT-scan that was made 4 weeks postoperatively. A total of 19 procedures were analyzed in this study. The mean duration of performing the CBCT-scan, including preparation and interpretation, was 8 min. Additional stone extraction, if applicable, had a mean duration of 11 min. The mean effective dose per CBCT-scan was 7.25 mSv. Additional extraction of residual fragments as imaged on the CBCT-scan occurred in nine procedures (47%). Of the follow-up CT-scans, 63% showed a stone-free status as compared to 47% of the intraoperative CBCT-scans. We conclude that the use of CBCT for the detection of residual stones in PCNL is meaningful, safe, and feasible.

scholarly journals Height difference between the vestibular and palatal walls and palatal width: a cone beam computed tomography approach

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
P. López-Jarana ◽  
C. M. Díaz-Castro ◽  
A. Falcão ◽  
C. Falcão ◽  
J. V. Ríos-Santos ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Cone Beam Computed Tomography ◽  
Cone Beam ◽  
Bone Thickness ◽  
Height Difference ◽  
Mean Values ◽  
The Mean ◽  
Maxilla And Mandible ◽  
Palatal Bone ◽  
Two Parameters

Abstract Background The objective of this study was to measure two parameters involved in tri-dimensional implant planning: the position of the buccal and palatal bone wall and the palatal thickness. Methods Cone beam computed tomography (CBCT) images (Planmeca ProMax 3D) of 403 teeth (208 upper teeth and 195 lower teeth) were obtained from 49 patients referred to the Dental School of Seville from January to December 2014. The height difference between the palatal and buccal walls was measured on the most coronal point of both walls. The thickness of the palatal wall was measured 2 mm from the most coronal point of the palatal wall. Results The mean values in the maxilla were 1.7 ± 0.9 mm for central and lateral incisors, 2.2 ± 1.7 mm for canines, 1.6 ± 0.9 mm for premolars and 1.9 ± 1.5 mm for molars. In the lower jaw, the mean values were 1.3 ± 0.8 mm for incisors, 1.7 ± 1.2 mm for canines, 2.3 ± 1.3 mm for premolars, and 2.6 ± 1.7 mm for molars. In the upper jaw, more than 55% of maxillary teeth (excluding second premolars and molars) presented mean height differences greater than 1 mm. In the mandible, more than 60% of incisors showed a buccal bone thickness of 1 mm from the apical to lingual aspect. All teeth except the second premolar presented a buccal wall located more than 1 mm more apically than the lingual bone wall. Conclusions The buccal bone wall is located more apically (greater than 1 mm) than the palatal or lingual table in most of the cases assessed. The thickness of the palatal or lingual table is also less than 2 mm in the maxilla and mandible, except in the upper canines and premolars and the lower molars.

Ionizing radiation and its considerations in imaging diagnosis: comparison of absorbed dose between cone beam computed tomography and multi-detector computed tomography in the head and neck

2021 ◽  
Author(s):  
P.L.E. Oliveira ◽  
C.R. Starling ◽  
C.L.P. Maurício ◽  
F.R. Guedes ◽  
M.A. Visconti ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Head And Neck ◽  
Cone Beam Computed Tomography ◽  
Absorbed Dose ◽  
Cone Beam ◽  
Thermoluminescent Dosimeters ◽  
Organ Tissue ◽  
The Mean ◽  
Average Adult ◽  
Multi Detector Computed Tomography

Introduction: The objective of this study was to compare the mean absorbed dose in patients undergoing head and neck examinations using two cone beam computed tomography (CBCT, Kodak and i-CAT) and one multi-detector computed tomography (MDCT). Methods: Three thermoluminescent dosimeters (TLDs), calibrated in air kerma, were positioned in 24 regions of the head and neck of a phantom simulating an average adult. The mean absorbed dose (mGy) values in these positions, for different organs and tissues, were obtained using correction factors, considering the ratio between the mass energy absorption coefficients of organ/tissue and air. Comparison between radiation doses in the most radiosensitive regions was done by calculating the ratio of these dose values, with propagated uncertainty. Results: The dose in all regions was significantly higher for MDCT when compared to CBCT. Concerning CBCT equipment, the Kodak device had a higher absorbed dose than the i-CAT for most of the regions tested. The uncertainty of the i-CAT was greater than that of the Kodak. Conclusion: Due to the considerable difference between absorbed doses, emphasizing the higher dose values obtained in MDCT, the dissemination of CBCT application in medicine is recommended, as well as further studies to broaden the criteria for use.

scholarly journals Comparison of the Hounsfield Unit Values Obtained From Cone-Beam Computed Tomography (CBCT) and Multidetector Computed Tomography (MDCT) Images for Different Bone Densities

2021 ◽  
Vol 7 (2) ◽  
Author(s):  
Atefeh Khavid ◽  
Mojgan Sametzadeh ◽  
Mostafa Godiny ◽  
Mohammad Mehdi Moarrefpour
Keyword(s):  
Computed Tomography ◽  
Cone Beam Computed Tomography ◽  
Pearson Correlation ◽  
Hounsfield Unit ◽  
Cone Beam ◽  
Ct Scanner ◽  
Significance Level ◽  
Dental Practitioners ◽  
Significant Difference ◽  
The Mean

Background and objective: In recent years, cone-beam computed tomography (CBCT) has become a key diagnostic tool in dentistry. CBCT can provide 3D images of the maxillofacial area to help dental practitioners in diagnosis and treatment, especially implant placement and treatment of pathogenic lesions. This study aimed to compare the Hounsfield Unit (HU) values obtained from CBCT images for bones of different densities with the corresponding HU values from MDCT images. Materials and methods: cube-shaped bone blocks of identical size were cut from the middle section of the cow ribs and femur area such that they had a layer of cortical bone in their buccal, lingual, and top surfaces and trabecular bone in the middle. MDCT scans were performed using a Somatom Sensation Ct Scanner. After determining HU from the results of these scans, nine suitable specimens from different ranges of HU were chosen for comparison. HU of the CBCT images was computed by the dedicated software of the CBCT machine. Finally, HU values obtained from MDCT and CBCT were compared. Data analysis was performed using SPSS version 25 at the 0.05 significance level. Results: The results showed a statistically significant difference between the mean HU from MDCT images and the mean HU from CBCT images (P<0.05). For similar specimens, CBCT produced higher mean HU values than MDCT. The Pearson correlation test detected a significant direct relationship between the HU values of specimens in MDCT and CBCT (P<0.05). Conclusion: For the tools and software used in this study, there was no significant difference between the HU values obtained from MDCT and CBCT, but the mean HU obtained from CBCT was higher than that from MDCT.

Volumetric Analysis of the Pterygopalatine Fossa by Semiautomatic Segmentation of Cone Beam Computed Tomography

2020 ◽  
Vol Publish Ahead of Print ◽  
Author(s):  
Max-Philipp Lentzen ◽  
Ali-Farid Safi ◽  
Maximilian Riekert ◽  
Veerle Visser-Vandewalle ◽  
Andrea Grandoch ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Cone Beam Computed Tomography ◽  
Volumetric Analysis ◽  
Pterygopalatine Fossa ◽  
Cone Beam ◽  
Semiautomatic Segmentation

Postoperative Assessment of Incisor Dental Implants Using Cone-Beam Computed Tomography

2010 ◽  
Vol 36 (5) ◽  
pp. 377-384 ◽  
Author(s):  
Munetaka Naitoh ◽  
Hiromitsu Nabeshima ◽  
Hisashi Hayashi ◽  
Takehiko Nakayama ◽  
Kenichi Kurita ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Dental Implants ◽  
Cone Beam Computed Tomography ◽  
Bone Grafts ◽  
Cone Beam ◽  
Postoperative Assessment ◽  
Labial Side ◽  
Bone To Implant Contact ◽  
The Mean ◽  
Postoperative Findings

Abstract The bone configuration surrounding anterior dental implants was postoperatively assessed using cone-beam computed tomography (CBCT). In 21 patients with a mean age of 41.5 years, 36 implants placed in the incisor region were postoperatively evaluated using CBCT. The rate of bone-to-implant contact (%) was calculated. The mean rate of bone-to-implant contact on the labial side was 78.3% with and 65.3% without bone grafts. The postoperative findings of incisor implants could be assessed using CBCT.

Detection Accuracy of Bone Defects Depending on Exposure Settings of Cone Beam Computed Tomography

2020 ◽  
Vol 40 (2) ◽  
pp. e65-e72
Author(s):  
Spyridon Vassilopoulos ◽  
Yiorgos Bobetsis ◽  
Michalis Mastoris ◽  
Eudoxie Pepelassi ◽  
Keti Nikopoulou-Karagianni
Keyword(s):  
Computed Tomography ◽  
Cone Beam Computed Tomography ◽  
Bone Defects ◽  
Cone Beam ◽  
Detection Accuracy
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