Impacted Lower Third Molar Fused with a Supernumerary Tooth—Diagnosis and Treatment Planning Using Cone-Beam Computed Tomography

This paper reported a case of fusion between an impacted third molar and a supernumerary tooth, in which a surgical intervention was carried out, with the objective of removing the dental elements. The panoramic radiography was complemented by the Donovan＇s radiographic technique; but because of the proximity of the dental element to the mandibular ramus, it was not possible to have a final fusion diagnosis. Hence, the Cone-Beam Computed Tomography--which provides precise three- dimensional information--was used to determinate the fusion diagnosis and also to help in the surgical planning. In this case report we observed that the periapical, occlusal and panoramic were not able to show details which could only be examined through the cone-beam computed tomo- graphy.

Efficacy of Daily Cone-Beam Computed Tomography as Part of a Rescan Protocol for Large Offset to Reduce the Inter-Fractional Motion of the Prostate

Purpose: To prospectively analyze the inter-fractional motion of the prostate in patients with prostate cancer treated with intensity-modulated radiation therapy (IMRT) using image-guided radiotherapy (IGRT) with daily cone-beam computed tomography (CBCT) as part of a rescan protocol for large offset, and to evaluate the efficacy of our protocol. Materials and Methods: Eligible patients were treated with the following protocol: 1) magnesium oxide and dimethylpolysiloxane were administered to ensure that patients had regular bowel movements;2) the patients were instructed to have an appropriately distended bladder during the planning CT and daily irradiation;3) the daily CBCT image was fused with the planning CT image using the prostate outline;and 4) if large offset was recognized, a rescan CBCT image was obtained after appropriate countermeasures, such as the discharge of gas and defecation, and re-registration was performed. Three shifts for the inter-fractional motion of the prostate were analyzed, in the fractions which needed the CBCT rescan;the displacement data after the final rescan were used. Results: Sixty-one patients were eligible, and a total of 2302 fractions were available for the analysis. Rescans of the CBCT for large offset were performed in 113 (5%) of the 2302 fractions. After the first rescan, the large offset was resolved in 106 (94%) of the 113 fractions. Excessive rectal gas was the reason for the large offset in 94 (83%) of the 113 fractions. The total mean and standard deviation of the inter-fractional motion of the prostate in the AP, LR, and SI directions were 1.1 ± 2.4, -0.1 ± 2.3, and 0.7 ± 3.0 mm, respectively. Conclusion: Large offset was recognized in 5% of all fractions. Daily CBCT with our rescan protocol could resolve the large offset, which was mainly caused by excessive rectal gas, and it may therefore be promising to reduce the inter-fractional motion of the prostate.

Practical limitations of cone-beam computed tomography in 3D cephalometry

3D cone beam computed tomography(CBCT) images offer a unique and new appreciation of the anatomical structures and underlying anomalies not possible with conventional radiographs.However,in almost all aspects of CBCT imaging,from utilization to application,inherent limitations and pitfalls exist.Importantly,these inherent limitations and pitfalls have practical implications which need to be addressed before the potential of this technology can be fully realized.The purpose of this review was to explore the current limitations and pitfalls associated with CBCT imaging to allow for better and more accurate understanding of the possibilities this imaging modality could offer,particularly pertaining to 3D cephalometry.

Comparison of bone alignment and fiducial marker alignment for online cone-beam computed tomography-guided radiation therapy for prostate cancer

Objective The aim of the study was to evaluate the coverage of the prostate when prostatic implanted fiducial markers are used to verify setup of the patients in comparison to the pelvic bones while using conebeam computed tomography(CBCT). Methods Seventeen patients with prostate cancer were included. For each patient, daily online CBCT was done. CT planning was matched with CBCT with the help of fiducial markers(3–5 markers) and another matching with done the help of pelvic bony landmarks. Registration of clinical target volume(CTV) 1 including prostate plus seminal vesicles and CTV2 including prostate only was done and were used to confirm the target volume during the process of matching. Delineation of the rectum on every CBCT was done. Two automatic margin representing planning target volume(PTV) were created. PTV1 was generated by adding 1 cm in all directions(PTV1a) and 0.7 cm in the posterior direction(PTV1b). PTV2 was generated by adding 0.5 cm in all directions(PTV2a) and 0.3 cm in the posterior direction(PTV2b). PTV1a was prescribed to receive 46 Gy in conventional fractionation with a boost dose of 30 Gy to PTV1b. The same dose was prescribed to PTV2a and PTV2b. Calculation of the percentage of intersection between CTV1and CTV2 created on CBCT with the original CTV scan was done. A comparison between the two CTVs(CTV1and CTV2) mean dose and the original delineated CTV was done. Then a comparison to the mean dose of the original CTV of PTV1a, PTV2a(CTV1a and CTV2a), and for PTV1b and PTV2b(CTV1b and CTV2b). Calculation of the mean rectal dose and also V60, V70 and V74 was done on the delineated rectum on every CBCT, and then a comparison to the planned original rectal dose. Results The created CTV1and CTV2 intersection percentage with the original CTV1and CTV2 significantly increased by 85%(range, 65%–95%, P < 0.05), when fiducial markers were used. The main difference of the received mean dose was significantly less in comparison to pelvic bone alignment(0.03% to 2% vs 0.03% to 11.6% for PTV1a, P < 0.006;0.01% to 1.8% vs 0.03% to 10.2% for PTV2a, P < 0.014;0.08 to 2.11 vs 0.04 to 11.29 for PTV1b, P < 0.015 and 0.01 to 1.79 vs 0.01 to 9.69 for PTV2b, P < 0.004). With the use of less PTV margins, significant decrease of the rectal mean dose, V60, V70 and V74 by P < 0.004, P < 0.004, P < 0.0005 and P < 0.009, respectively. Reduction of the CTV1a and CTV1b mean dose by 1.13% and 0.28% in comparison to the initial CTV1a and CTV2a.Conclusion A significant improvement of prostatic cancer patients alignment when fiducial markers are used, with more homogenous dose distribution, and with significant decrease in PTV margins. The delivered rectal dose is significantly less allowing prostate dose escalation.

A Pilot Survey of Odontomas for Size Constancy Using Cone-Beam Computed Tomography: Effect of Age, Sex, Lesion Location, and Histological Type: A Case Series

Objectives: Odontoma is the most common type of odontogenic tumors. Many studies have analyzed the statistical associations between odontoma location and patient age and sex, according to the histological tumor type. However, few studies have assessed odontoma morphological characteristics using cone-beam computed tomography (CBCT). We aimed to evaluate the association between odontoma location and size. Methods: We performed CBCT on patients with odontomas (19 patients;10 women, 9 men;average age, 12.6 [range, 6 - 34] years) according to the pathology type at a university hospital between April 2008 and February 2017. The locations of the lesions were noted, and their sizes were measured on CBCT images. Buccolingual, mesiodistal, and vertical diameters of the lesions were recorded on the same slice with the greatest diameters on axial, coronal, and sagittal CBCT images. Results: Altogether, 9 (47.4%) and 10 (52.6%) odontomas were located in the mandible and maxilla, respectively. There was no significant difference in the mesiodistal and vertical diameters on the CBCT image between the mandibular and maxillary groups when the odontoma size was compared with location (p < 0.05). However, the average diameters in only the buccolingual diameter were significantly greater in the maxilla. There were no significant differences between the two groups according to sex, age, or histological type. Conclusions: These data suggest that the sizes of odontomas in the maxilla are affected by bone expansion in the buccolingual direction, but they may be invariable in most settings. Three-dimensional assessment across the age groups suggests a lack of variation in size.

Usefulness of intra-procedural cone-beam computed tomography in modified balloon-occluded retrograde transvenous obliteration of gastric varices

AIM:To evaluate whether intra-procedural conebeam computed tomography(CBCT)performed during modified balloon-occluded retrograde transvenous obliteration(mB RTO)can accurately determine technical success of complete variceal obliteration.METHODS:From June 2012 to December 2014,15 patients who received CBCT during m BRTO for treatment of portal hypertensive gastric variceal bleeding were retrospectively evaluated.Three-dimensional(3D)CBCT images were performed and evaluated prior to the end of the procedure,and these were further analyzed and compared to the pre-procedure contrast-enhanced computed tomography to determine the technical success of m BRTO including:Complete occlusion/obliteration of:(1)gastrorenal shunt(GRS);(2)gastric varices;and(3)afferent feeding veins.Post-mB RTO contrast-enhanced CT was used to confirm the accuracy and diagnostic value of CBCT within 2-3 d.RESULTS:Intra-procedural 3D-CBCT images were 100% accurate in determining the technical success of m BRTO in all 15 cases.CBCT demonstrated complete occlusion/obliteration of GRS,gastric varices,collaterals and afferent feeding veins during m BRTO,which was confirmed with post-m BRTO CT.Two patients showed incomplete obliteration of gastric varices and feeding veins on CBCT,which therefore required additional gelfoam injections to complete the procedure.No patient required additional procedures or other interventions during their follow-up period(684 ± 279 d).CONCLUSION:CBCT during mB RTO appears to accurately and immediately determine the technical success of mB RTO.This may improve the technical and clinical success/outcome of m BRTO and reduce additional procedure time in the future.

Alveolar Ridge Preservation Utilizing Composite (Bioceramics/Collagen) Graft: A Cone-Beam Computed Tomography Assessment in a Randomized Split-Mouth Controlled Trial

Background: The vast percentage of the alveolar bone resorption process happens within the first 12 to 24 weeks post extraction;however, this phenomenon is chronic, and the alveolar ridge continues to resorb. In order to prevent this reduction or at least recompense the loss of bone dimensions, the alveolar ridge preservation (ARP) technique was developed. Objectives: This research studied the vertical and horizontal bone dimensional changes as a result of non-molar teeth extraction alone against extraction with alveolar ridge preservation utilizing composite (bioceramics/collagen) graft by cone-beam computed tomography radiographies analyses. Material and Methods: This research was a randomized split-mouth controlled trial. 12 patients need extraction of the maxillary non-molar teeth were enrolled and allocated into 2 groups. 12 sockets after atraumatic extraction were filled with a composite graft in the role of the test group, 12 sockets left to unassisted healing after atraumatic extraction without any graft materials in the role of the control group. Two CBCT radiographs were taken at baseline and at 4 months after extraction for comparison. Both vertical and horizontal resorptions of the alveolar ridge were analyzed between test and control group by CBCT radiographs. Results: 4 months after extraction, there was a mean of vertical alveolar bone resorption compared with the baseline (0.56 ± 0.15 mm) in the test group and (1.47 ± 0.30 mm) in the control group. Whereas it was a mean of horizontal alveolar bone resorption compared with the baseline (0.90 ± 0.16 mm) in the test group and (2.26 ± 0.30 mm) in the control group. Therefore, there was a significant difference between the two groups. Conclusions: Within the limitations of this research, we demonstrated that the osteogen-plug technique significantly decreased the reduction of the bone dimensional in comparison to the tooth extraction alone, and showed that the dimensional change of the alveolar ridge after tooth extraction was minimized by using an osteogen-plug.

Assessment of liver ablation using cone beam computed tomography

AIM: To investigate the feasibility and accuracy of cone beam computed tomography(CBCT) in assessing the ablation zone after liver tumor ablation.METHODS: Twenty-three patients(17 men and 6 women, range: 45-85 years old, mean age 65 years) with malignant liver tumors underwent ultrasoundguided percutaneous tumor ablation [radiofrequency(n = 14), microwave(n = 9)] followed by intravenous contrast-enhanced CBCT. Baseline multidetector computed tomography(MDCT) and peri-procedural CBCT images were compared. CBCT image quality was assessed as poor, good, or excellent. Image fusion was performed to assess tumor coverage, and quality of fusion was rated as bad, good, or excellent. Ablation zone volumes on peri-procedural CBCT and post-procedural MDCT were compared using the nonparametric paired Wilcoxon t-test.RESULTS: Rate of primary ablation effectiveness was 100%. There were no complications related to ablation. Local tumor recurrence and new liver tumors were found 3 mo after initial treatment in one patient(4%). The ablation zone was identified in 21/23(91.3%) patients on CBCT. The fusion of baseline MDCT and peri-procedural CBCT images was feasible in all patients and showed satisfactory tumor coverage(at least 5-mm margin). CBCT image quality was poor, good, and excellent in 2(9%), 8(35%), and 13(56%), patients respectively. Registration quality between periprocedural CBCT and post-procedural MDCT images was good to excellent in 17/23(74%) patients. The median ablation volume on peri-procedural CBCT and post-procedural MDCT was 30 cm3(range: 4-95 cm3) and 30 cm3(range: 4-124 cm3), respectively(P-value > 0.2). There was a good correlation(r = 0.79) between the volumes of the two techniques. CONCLUSION: Contrast-enhanced CBCT after tumor ablation of the liver allows early assessment of the ablation zone.

Cone beam computed tomographic analyses of alveolar bone anatomy at the maxillary anterior region in Chinese adults

To provide an anatomical basis for clinical implant esthetics,we evaluated the morphology of the nasopalatine canal（NPC） and analyzed labial and interproximal bone anatomy at the maxillary anterior region.We sought to investigate the effect of maxillary protrusion and tooth labiolingual inclination on labial bone anatomy in Chinese adults.Three dimensional（3D） images were reconstructed using cone-beam computed tomography（CBCT） images from 80 Chinese subjects and by SimPlant 11.04.The dimensions of the NPC,the thickness and profile of the labial bone,the width and height of the interproximal bone,angle sella-nasion-subspinale（SNA） and angle upper central incisor-nasion,subspinale（U1-NA） were measured.The incisive foramen of the NPC was markedly wider than its nasal foramen.The dimension of its labial bone wall demonstrated an increasing width from the crestal to apical measurements.The labial bone at the maxillary anterior region was rather thin,especially at 3 mm below the cemento-enamel junction（CEJ） and the mid-root level;the profile of the labial bone was more curved at the central incisor,and the interproximal bone became wider and shorter posteriorly.There were significant relationships between maxillary protrusion and labial bone profile,tooth labiolingual inclination and labial bone thickness（P 〈 0.02）.To achieve optimal esthetic outcome of implant,bone augmentation is necessary at the maxillary anterior region.For immediate or early placement at the maxillary anterior region,the implant should be located palatally to reduce labial bone resorption and marginal recession;its apex should be angulated palatally to avoid labial perforation at the apical region.To protect the NPC,implants at the central incisor region should be placed away from NPC.

Use of cone beam computed tomography in periodontology

Diagnosis of periodontal disease mainly depends on clinical signs and symptoms. However, in the case of bone destruction, radiographs are valuable diagnostic tools as an adjunct to the clinical examination. Two dimensional periapical and panoramic radiographs are routinely used for diagnosing periodontal bone levels. In two dimensional imaging, evaluation of bone craters, lamina dura and periodontal bone level is limited by projection geometry and superpositions of adjacent anatomical structures. Those limitations of 2D radiographs can be eliminated by three-dimensional imaging techniques such as computed tomography. Cone beam computed tomography(CBCT) generates 3D volumetric images and is also commonly used in dentistry. All CBCT units provide axial, coronal and sagittal multi-planar reconstructed images without magnification. Also, panoramic images without distortion and magnification can be generated with curved planar reformation. CBCT displays 3D images that are necessary for the diagnosis of intra bony defects, furcation involvements and buccal/lingual bone destructions. CBCT applications provide obvious benefits in periodontics, however; it should be used only in correctindications considering the necessity and the potential hazards of the examination.

Three-dimensional Localization of Impacted Canines and Root Resorption Assessment Using Cone Beam Computed Tomography

Summary： The purpose of this study was to develop a new way to localize the impacted canines from three dimensions and to investigate the root resorption of the adjacent teeth by using cone beam computed tomography （CBCT）. Forty-six patients undergoing orthodontic treatments and having impacted canines in Tongii Hospital were examined. The images of CBCT scans were obtained from KaVo 3D exam vision. Angular and linear measurements of the cusp tip and root apex according to the three planes （mid-sagittal, occlusal and frontal） have been taken using the cephalometric tool of the InVivo Dental Anatomage Version 5.1.10. The measurements of the angular and linear coordinates of the maxillary and mandibular canines were obtained. Using this technique the operators could envision the location of the impacted canine according to the three clinical planes. Adjacent teeth root resorption.of 28.26 % was in the upper lateral incisors while 17.39% in upper central incisors, but no lower root resorption was found in our samples. Accurate and reliable localization of the impacted canines could be obtained from the novel analysis system, which offers a better surgical and orthodontic treatment for the patients with impacted canines.

Applied Anatomic Site Study of Palatal Anchorage Implants Using Cone Beam Computed Tomography

Aim The purpose of this study was to conduct quantitative research on bone height and bone mineral density of palatal implant sites for implantation, and to provide reference sites for safe and stable palatal implants. Methodology Three-dimensional reformatting images were reconstructed by cone beam computed tomography （CBCT） in 34 patients, aged 18 to 35 years, using EZ Implant software. Bone height was measured at 20 sites of interest on the palate. Bone mineral density was measured at the 10 sites with the highest implantation rate, classified using K-mean cluster analysis based on bone height and bone mineral density. Results According to the cluster analysis, 10 sites were classified into three clusters. Significant differences in bone height and bone mineral density were detected between these three clusters （P〈0.05）. The greatest bone height was obtained in cluster 2, followed by cluster 1 and cluster 3. The highest bone mineral density was found in cluster 3, followed by cluster 1 and cluster 2. Conclusion CBCT plays an important role in pre-surgical treatment planning. CBCT is helpful in identifying safe and stable implantation sites for palatal anchorage.

Bone mineral density in cone beam computed tomography:Only a few shades of gray

Cone beam computed tomography(CBCT) has often been used to determine the quality of craniofacial bone structures through the determination of mineral density, which is based on gray scales of the images obtained. However, there is no consensus regarding the accuracy of the determination of the gray scales in these exams. This study aims to provide a literature review concerning the reliability of CBCT to determine bone mineral density. The gray values obtained with CBCT show a linear relationship with the attenuation coefficients of the materials, Hounsfield Units values obtained with medical computed tomography, and density values from dual energy X-ray absorciometry. However, errors are expected when CBCT images are used to define the quality of the scanned structures be-cause these images show inconsistencies and arbitrari-ness in the gray values, particularly when related to abrupt change in the density of the object, X-ray beam hardening effect, scattered radiation, projection data discontinuity-related effect, differences between CBCTdevices, changes in the volume of the field of view(FOV), and changes in the relationships of size and position between the FOV and the object evaluated. A few methods of mathematical correction of the gray scales in CBCT have been proposed; however, they do not generate consistent values that are independent of the devices and their configurations or of the scanned objects. Thus, CBCT should not be considered the ex-amination of choice for the determination of bone and soft tissue mineral density at the current stage, par-ticularly when values obtained are to be compared to predetermined standard values. Comparisons between symmetrically positioned structures inside the FOV and in relation to the exomass of the object, as it occurs with the right and left sides of the skull, seem to be viable because the effects on the gray scale in the re-gions of interest are the same.

Cone beam computed tomographic evaluation of pharyngeal airway in North Indian children with different skeletal patterns

BACKGROUND In growing patients with skeletal discrepancies,early assessment of functional factors can be vital for the restoration of normal craniofacial growth.AIM To compare airway volumes in patients with mandibular retrognathism with the normal anteroposterior skeletal relationship,thereby assessing the association between cephalometric variables and airway morphology.METHODS Cone-beam computed tomography volume scans,and lateral cephalograms,3-dimensional airway volume and cross-sectional areas of 120 healthy children(54 boys and 66 girls mean age 15.19±1.28)which were done for orthodontic assessment were evaluated.The subjects were divided into 2 groups based on the angle formed between point A,Nasion and point B(ANB)values and cephalometric variables(such as anterior and posterior facial height,gonial angle etc.)airway volumes,and cross-sectional measurements were compared using independent t tests.Pearson’s correlation coefficient test was used to detect any relationship of different parts of the airway and between airway volume and 2-dimensional cephalometric variables.RESULTS Means and standard deviations for cephalometric,cross-sectional,and volumetric variables were compared.ANB,mandibular body length and facial convexity were statistically highly significant(P<0.01)whereas condylion to point A,nasal airway and total airway volume(P<0.05)were statistically significant.The nasal airway volume and the superior pharyngeal airway volume had a positive correlation(P<0.01),nasal airway was correlated to middle(P<0.05)and total airway superior had a relation with middle(P<0.05),inferior and total airway(P<0.05),middle was related to all other airways;inferior was also related to all the airways except nasal.Lateral cephalometric values were positively correlated with the airway volume with Frankfurt Mandibular Plane Angle and facial convexity showed significant correlations with total airway volume(P<0.05).Additionally,ANB angle was significantly correlated with total airway volume and superior airway(P<0.05).CONCLUSION The mean total airway volume in patients with retrognathic mandible was significantly smaller than that of patients with a normal mandible.

Clinical Endodontic Applications of Cone Beam-Computed Tomography in Modern Dental Practice

Nearly two decades since Cone Beam-Computed Tomography (CBCT) was introduced in dentistry, this technology has been proven to be a useful asset in modern dental practice. The information gleaned from a CBCT scan influences treatment decisions and prognostication of challenging endodontic cases. The authors present six cases that utilized CBCT to diagnose vertical root fracture, to assess resorption, to guide the clinician in overcoming anatomical complexities, to hurdle diagnostic dilemmas and to perform pre-surgical evaluation. Initially, a thorough clinical assessment was performed;however, conventional periapical radiographs were not able to provide sufficient information to arrive at a definite diagnosis or a thorough treatment plan. CBCT was therefore deemed helpful for these cases. Clearly, there are advantages to using CBCT. With a better understanding of each case, the clinician can plan a definitive treatment plan and offer a clearer case prognosis to their patient.

Scattering correction method for panel detector based cone beam computed tomography system

A scattering correction method for a panel detector based cone beam computed tomography system is presented. First, the x-ray spectrum of the system is acquired by using the Monte Carlo simulation method. Secondly, scattered photon distribution is calculated and stored as correction matrixes by using the Monte Carlo simulation method according to scanned objects and computed tomography system specialties. Thirdly, scattered photons are removed from projection data by correction matrixes. A comparison of reconstruction image between before and after scattering correction demonstrates that the scattering correction method is effective for the panel detector based cone beam computed tomography system.

Genial tubercles: Morphological study of the controversial anatomical landmark using cone beam computed tomography

BACKGROUND Identification of the morphology of the genial tubercles (GTs) is valuable for different dental applications. The morphological pattern of the GTs is still controversial, and therefore, the study of its morphology using cone beam computed tomography (CBCT) plays a valuable role in resolving the controversy. AIM To assess the morphological pattern, dimensions and position of the GTs using CBCT among a selected Saudi population. METHODS CBCT records of 155 Saudi subjects (49 female and 106 male) were used to assess the pattern and size of the GTs and to determine the distance from the apices of the lower central incisors to the superior border of the incisors (I-SGT) and the distance from the inferior border of the GTs to the menton (IGT-M). RESULTS The results of this study showed that the most common morphological pattern was of two superior GTs and a rough impression below them (36.8%), followed by two superior GTs and a median ridge representing fused inferior GTs below them (22.6%) and a single median eminence or projection (20%). The classically described pattern, of two superior and two inferior GTs placed one above the other, was found in only 14.2% of cases, while 6.4% of the studied cases had no GTs. The mean width and height were 6.23 ± 1.93 mm and 6.67 ± 3.04 mm, respectively, while the mean I-SGT and IGT-M measurements were 8.26 ± 2.7 mm and 8.13 ± 3.07 mm, respectively. CONCLUSION The GTs are a controversial anatomical landmark with wide variation in their morphological pattern. The most common pattern among the studied Saudi sample was of two superior GTs and a rough impression below them, and there were no significant differences between males and females.

Analysis of Dose Calculation Accuracy in Cone Beam Computed Tomography with Various Amount of Scattered Photon Contamination

Cone-beam computed tomography (CBCT) images have inaccurate CT numbers because of scattered photons. Thus, quantitative analysis of scattered photons that affect an electron density (ED) curve and calculated doses may be effective information to achieve CBCT-based radiation treatment planning. We quantitatively evaluated the effect of scattered photons on the accuracy of dose calculations from a lung image. The Monte Carlo method was used to calculate CBCT projection data, and we made two calibration curves for conditions with or without scattered photons. Moreover, we applied cupping artifact correction and evaluated the effects on image uniformity and dose calculation accuracy. Dose deviations were compared with those of conventional CT in conventional and volumetric intensity modulated arc therapy (VMAT) planning by using γ analysis and dose volume histogram (DVH) analysis. We found that cupping artifacts contaminated the scattered photons, and the γ analysis showed that the dose distribution was most decreased for a scattered photon ratio of 40%. Cupping artifact correction significantly improved image uniformity;therefore, ED curves were near ideal, and the pass rate results were significantly higher than those associated with the scattered photon effect in 65.1% and 78.4% without correction, 99.5% and 97.7% with correction, in conventional and VMAT planning, respectively. In the DVH analysis, all organ dose indexes were reduced in the scattered photon images, but dose index error rates with cupping artifact correction were improved within approximately 10%. CBCT image quality was strongly affected by scattered photons, and the dose calculation accuracy based on the CBCT image was improved by removing cupping artifacts caused by the scattered photons.

Knowledge and Practices of Dentists, Oral and Maxillofacial Surgeons of Cone Beam Computed Tomography (CBCT) and the Dentascanner in a Low Income Country: Case of Togo

Background: In dental-maxillofacial imaging, 3D sectional imaging progressively replaces conventional 2D imaging in developed countries. They are based specially on Computed tomography (CT-Scan), with the Dentascan application and cone beam computed tomography (CBCT). In developing countries those technics are newly introduced. Aim: This study aimed at studying the knowledge and practices of dentist and oral and maxillofacial surgeons on sectional imaging such as Dentascan and Cone Beam Computed Tomography (CBCT). Materials and Methods: We conducted an anonymous survey among dentists and oral maxillofacial surgeons in Togo over one month. Results: The response rate was 78.79% (27/33). They were mainly male sex (sex ratio of 2.25 men for one woman). They were aged between 27 and 71 years old with an average of 49.69 years old. The majority (61.54%) had a professional experience over 20 years. The majority of respondents (65.38%) believed their level of knowledge about dental x-Ray was poor. Half of them (50%) confirmed that they had never asked for a Dentascan, and 15.38% asked from time to time for it and only two (7.69%) asked often for this test. 96.15% confirm they have no knowledge of the Dentascan. Regarding the CBCT, 84.62% didn’t ask for it because this technique did not exist in Togo before. 69.20% of respondents confessed to be interested in continuing training on sectional imaging. Conclusion: This study shows that sectional imaging is very little used by oral and dental practitioners in Togo because of the ignorance of the new techniques and the absence of the CBCT. It is therefore necessary to promote the teaching of the new technique of sectional imaging in the training syllabus of oral and dental specialists and to initiate continuing medical training.

Cone beam computed tomography aided diagnosis and treatment of endodontic cases:Critical analysis

Although intraoral radiographs still remain the imaging method of choice for the evaluation of endodontic patients, in recent years, the utilization of cone beam computed tomography(CBCT) in endodontics showed a significant jump. This case series presentation shows the importance of CBCT aided diagnosis and treatment of complex endodontic cases such as; root resorption, missed extra canal, fusion, oblique root fracture, nondiagnosed periapical pathology and horizontal root fracture. CBCT may be a useful diagnostic method in several endodontic cases where intraoral radiography and clinical examination alone are unable to provide sufficient information.