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2021 ◽  
Vol 3 (17) ◽  
pp. 1816-1821
Author(s):  
Lamees I. El Nihum ◽  
M. Mujeeb Zubair ◽  
Ponraj Chinnadurai ◽  
Eric K. Peden

2021 ◽  
Author(s):  
Jie Zhou ◽  
Jieni Fu ◽  
Mo Xiao ◽  
Yangyang Lv ◽  
Fei Wu ◽  
...  

Abstract Background: Develop a new technique based on contrast-enhanced cone beam computed tomography (CBCT) to improve the detection of cracked teeth and the accuracy of crack depth evaluation in vitro. Methods: We developed an in vitro artificial simulation model of cracked teeth. Pre-experimental CBCT (pre-CBCT), and micro-computed tomography (micro-CT) were first performed for all cracked teeth (n = 31). Contrast-enhanced CBCT was then performed by infiltrating the crack with ioversol under vacuum conditions. The results of pre-CBCT, micro-CT, and contrast-enhanced CBCT were recorded. SPSS v.26.0 software (IBM Corp, Somers, NY) and R software , version 3.6.0 (R Foundation for Statistical Computing; http://www.r-project.org/) and RStudio 1.1.463 (RStudio, PBC, Boston, MA, US) were used to perform the statistical analysis for the study.Results: The sensitivities of pre-CBCT and contrast-enhanced CBCT were 48.4%, and 67.7%, respectively. ICC value of crack depth as measured by pre-CBCT and contrast-enhanced CBCT was 0.847 (95% confidence interval:0.380-0.960; P < 0.001). The areas under ROC curves (AUC) of pre-CBCT and contrast-enhanced CBCT were different, the AUC of pre-CBCT was 0.958 (P = 0.000, 95% CI :0.843-1.074), and the AUC of enhanced CBCT was 0.979 (P = 0.000, 95% CI :0.921-1.037), and the difference was not statistically significant (Z=-0.707, P = 0.480). The ICC value of crack depth as measured by contrast-enhanced CBCT and micro-CT was 0.753 (95% CI: 0.248-0.911; P < 0.001). Conclusion: Contrast-enhanced CBCT under vacuum conditions with a contrast medium can only significantly improve the cracks detection rate of cracked teeth, but not measure the crack depths accurately.


Author(s):  
Salam Dhou ◽  
Mohanad Alkhodari ◽  
Dan Ionascu ◽  
Christopher Williams ◽  
John H. Lewis

A method for generating fluoroscopic (time-varying) volumetric images using patient-specific motion models derived from 4-dimensional cone-beam CT (4D-CBCT) images is developed. 4D-CBCT images acquired immediately prior to treatment have the potential to accurately represent patient anatomy and respiration during treatment. Fluoroscopic 3D image estimation is done in two steps: 1) deriving motion models and 2) optimization. To derive motion models, every phase in a 4D-CBCT set is registered to a reference phase chosen from the same set using deformable image registration (DIR). Principal components analysis (PCA) is used to reduce the dimensionality of the displacement vector fields (DVFs) resulting from DIR into a few vectors representing organ motion found in the DVFs. The PCA motion models are optimized iteratively by comparing a cone-beam CT (CBCT) projection to a simulated projection computed from both the motion model and a reference 4D-CBCT phase, resulting in a sequence of fluoroscopic 3D images. Patient datasets were used to evaluate the method by estimating the tumor location in the generated images compared to manually defined ground truth positions. Experimental results showed that the average tumor mean absolute error (MAE) along the superior-inferior (SI) direction and the 95th percentile in two patient datasets were (2.29 mm and 5.79 mm) for patient 1 and (1.89 mm and 4.82 mm) for patient 2. This study has demonstrated the feasibility of deriving 4D-CBCT-based PCA motion models that have the potential to account for the 3D non-rigid patient motion and localize tumors and other patient anatomical structures on the day of treatment.


2021 ◽  
pp. 105566562110556
Author(s):  
Kaninut Phienwej ◽  
Marasri Chaiworawitkul ◽  
Dhirawat Jotikasthira ◽  
Krit Khwanngern ◽  
Patiyut Sriwilas

Objective To compare the use of a computer simulation by Mimics software and the water displacement method as means for measurement of alveolar cleft volume on cone beam computed tomography (CBCT) data. Design Prospective study. Settling Institutional research. Patients Patients with unilateral complete cleft lip and palate (UCCLP) who would undergo alveolar bone grafting. Interventions CBCT images of twenty patients with UCCLP were included in the study. In the first method, the water displacement method was adopted to measure volume of plasticine filled in the alveolar cleft imprinted on 3D printed model of maxilla. In the second method a volumetric assessment function in Mimics software was adopted to measure volume of 3D virtual model of alveolar cleft constructed from CBCT images. A comparison on the alveolar cleft volumes derived from the two methods was assessed using the statistical paired t-test. Main Outcome Measure The paired-t test showed no statistically significant difference between alveolar cleft volumes measured by the two methods ( P = 0.075). Results Mean volume of the alveolar cleft measured by the water displacement method was 1.03 ± 0.31 ml whereas by the computer simulation using Mimics software the value was 1.00 ± 0.31 ml. The mean difference between the two methods was 0.03 ± 0.08 ml. Conclusion The computer simulation by Mimics software as a means for measurement of alveolar cleft volume on CBCT data is as accurate as the measurement by the water displacement method.


2021 ◽  
Vol 21 ◽  
pp. e225442
Author(s):  
Nayara Stefany Leite-de-Lima ◽  
Eduardo Felippe Duailibi-Neto ◽  
Israel Chilvarquer ◽  
João Gualberto Cerqueira Luz

Aim: To describe cone-beam computed tomography (CBCT) features in patients with temporomandibular disorders (TMDs), in terms of degenerative changes, condylar excursions and positioning as well as their possible correlations with signs and symptoms. Methods: Clinical records of patients diagnosed with TMD who were seen between January 2018 and December 2019 were retrospectively evaluated. These patients were divided into the following groups based on the Diagnostic Criteria for Temporomandibular Disorders (DC/TMD): arthralgia, myalgia, and arthralgia and myalgia groups. The CBCT examination findings of the patients were evaluated in relation to degenerative changes, estimates of condylar excursion, and condylar positioning. The likelihood ratio test was used to verify the possible differences among the three groups, whereas the chi-square test was used to verify the possible differences among the signs and symptoms for the tomographic findings (p ≤ 0.050). Results: In this study, 65 patients with TMD were included. These patients were predominantly female (84.6%) with a mean age of 40.6 years. Tomographic findings of flattening, hyperexcursion and posterior condylar positioning were frequent. A significant correlation was noted between osteophyte and lateral capsule pain (p = 0.027), erosion and posterior capsule pain (p = 0.026), and flattening, pseudocysts (p < 0.050) and condylar excursion (p < 0.001) with mouth opening. Conclusion: Few correlations were noted between degenerative changes and signs of joint pain as well as degenerative changes and condylar hypoexcursion with mouth opening. These correlations were likely associated with division by diagnosis, whereas condylar positioning did not correlate with signs and symptoms.


2021 ◽  
Vol 10 (15) ◽  
pp. e351101522978
Author(s):  
Ana Carolina Neves Melgaço de Lima ◽  
Dominique A. Peniche ◽  
Thais M. C. Coutinho ◽  
Fábio R. Guedes ◽  
Maria Augusta Visconti ◽  
...  

Objective: To evaluate the dimensions of the nasopalatine canal (NPC) and its relationship with the maxillary central incisors (MCI) using cone-beam computed tomography (CBCT) and to determine variations in the NPC in relation to age and gender. Methods: CBCT scans from 333 patients (67% female; 35.9 ± 14.6 years) were included. The CBCT scan was analyzed to determine the length and diameter of the NPC, the distance between the NPC and the MCI, and to evaluate the morphology of the NPC. The data were analyzed using the independent Student's t-test, the Mann–Whitney and Kruskal–Wallis tests, and Dunn's post-test (p < 0.05). Results: The average diameter and length of the NPC were 2.92 ± 0.91 mm and 12.67 ± 3.32 mm, respectively. The minimum and maximum distance between the MCI and the NPC were 0.78 ± 0.42 mm and 2.56 ± 1.38 mm, respectively. The NPC of male patients was greater in length compared with the female patients (p < 0.05). The majority presented a funnel-like morphology (34.1%), followed by a cylindrical morphology (27.5%). Conclusions: There was variability in the dimensions of the NPC and its relationship with the MCI, which was influenced by gender and age.


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