EXTRAORAL AND CBCT DENTAL EXPOSURES IN PORTUGAL

2020 ◽  
Vol 190 (3) ◽  
pp. 283-288
Author(s):  
Hugo Trindade ◽  
Inês Morais ◽  
Abigail Moreira
Keyword(s):  
Computed Tomography ◽  
Cone Beam ◽  
X Rays ◽  
Lateral Projection ◽  
The Third ◽  
A Value ◽  
Wide Range ◽  
Patient Doses ◽  
Range Of Values ◽  
Made In

Abstract Data from dental extraoral and cone beam computed tomography (CBCT) exposures in Portugal (2019) were gathered, and patient doses for standard adult exams were evaluated. In panoramic X-rays, 442 units (34% of the existing licensed units) were tested, with a third quartile value (PKA) of 82 mGy.cm2. For cephalometric radiography (88 units), the third quartile value (Ki) was 0.3 mGy for the posteroanterior projection and 0.2 mGy for lateral projection. In CBCT (69 units), the doses for the placement of an upper first molar implant were evaluated with a third quartile value (PKA) of 820 mGy.cm2. Due to the wide range of values (74–3687 mGy.cm2), the CBCT data were divided by FOV dimensions: for small FOV (average FOV of 7 ×8 cm), a value of 580 mGy.cm2 was obtained and for medium FOV (average FOV of 13 × 12 cm) a value of 1167 mGy.cm2. The number of annual panoramic X-rays made in Portugal was 208 per 1000 inhabitants, which is higher than the value for other countries.

scholarly journals Framing the Values of Vernacular Architecture for a Value-Based Conservation: A Conceptual Framework

2021 ◽  
Vol 13 (9) ◽  
pp. 4974
Author(s):  
Obafemi A. P. Olukoya
Keyword(s):  
Vernacular Architecture ◽  
Conservation Strategy ◽  
Participatory Process ◽  
Value Assessment ◽  
A Value ◽  
Wide Range ◽  
Flexible Framework ◽  
Value Model ◽  
Contextual Values ◽  
Range Of Values

While a growing number of researchers have provided series of tough critiques of the typology-led heritage value assessment over the recent years, the impacts have been constrained by the continued obsession with expanding the list of the predetermined value typologies rather than escaping its limitations. While these sustained debates have provided important insights, this article argues that operationalizing these predetermined ‘one-size-fits-all’ value typologies is symptomatic of a number of shortcomings, especially in the context of capturing the pluralities of values in contextualized heritage such as vernacular architecture. It also often undermines inclusivity and participation in the valuing processes. However, rather than simply rejecting the values-based paradigm, this article proposes a conceptual value assessment framework that is informed by the theorization of vernacular architecture as a contextualized heritage. The proposed Vernacular Value Model (VVM) puts forward the ‘when(s)’ and ‘how(s)’ of amalgamating both technical and normative processes to capture the range of contextual values present in built vernacular heritage. To this end, this article posits that by drawing on such a proposed flexible framework, the conservation strategy for built vernacular heritage can be propagated as an inclusive and participatory process which captures the wide range of values for a more sustainable practices for conservation.

scholarly journals The Anatomical Position and Size of Greater Palatine Foramen and Canal in an Iranian Sample Using Cone Beam Computed Tomography

2021 ◽  
Author(s):  
Solmaz Valizadeh ◽  
Seyedeh Mahshid Ahmadi ◽  
Mitra Ghazizadeh Ahsaie ◽  
Zahra Vasegh ◽  
Navid Jamalzadeh
Keyword(s):  
Computed Tomography ◽  
Average Length ◽  
Third Molar ◽  
Cone Beam ◽  
P Value ◽  
Second Molar ◽  
Anatomical Position ◽  
The Third ◽  
Greater Palatine Foramen ◽  
The Right

Abstract IntroductionDetection of exact location of greater palatine foramen and its anatomical variations are vital prior to posterior maxillary surgeries and gingival grafts. The aim of this study is to determine the anatomical position and size of the greater palatine canal (GPC) and foramen (GPF) using cone beam computed tomography (CBCT) scans.Materials and methodsIn this descriptive-analytic study, CBCT images of 148 patients were assessed. To determine the anatomical foramen position, the posterior maxilla area was divided into five regions on the axial view (A: from the mesial surface of the second molar to the center of the second molar, B: from the center of the second molar to its distal, C: from the mesial surface of the third molar to the center of the third molar, D: from the center of the third molar to the distal of the third molar, E: distal to the third molar.). The length of the canal was investigated on both coronal and sagittal views. Independent and paired T-test were used to analyze the data.ResultsAmong 80 females -68 males, the anatomical position of the GPF was mainly located in region E on the left (55%) and the right (50%), and then, respectively, in region D and region C. The mean diameter of GPF was 4/48 mm on the left and 4/63 mm on the right side (P-value = 0/01). The average length of the canal on the coronal view was 29.46 mm on the left side and 29.75 mm on the right (P-Value = 0/005). The average length of the canal on the sagittal view was 29.62 mm on the left and 30.02 mm on the right (P-value = 0/001).ConclusionThe anatomical position of the GPF was primarily located distal to the third maxillary molar. CBCT is a valuable diagnostic tool for evaluation of vital anatomic landmarks in the maxillofacial region prior to surgeries and interventions.

scholarly journals Accuracy of cone-beam computed tomography in defining spatial relationships between third molar roots and inferior alveolar nerve

2016 ◽  
Vol 10 (04) ◽  
pp. 454-458 ◽  
Author(s):  
Roberto Pippi ◽  
Marcello Santoro ◽  
Ferdinando D'Ambrosio
Keyword(s):  
Computed Tomography ◽  
Cone Beam Computed Tomography ◽  
Root Morphology ◽  
Inferior Alveolar Nerve ◽  
Third Molar ◽  
Root Surface ◽  
Cone Beam ◽  
Spatial Relationships ◽  
Third Molars ◽  
The Third

ABSTRACT Objective: Cone-beam computed tomography (CBCT) has been proposed in surgical planning of lower third molar extraction. The aim of the present study was to assess the reliability of CBCT in defining third molar root morphology and its spatial relationships with the inferior alveolar nerve (IAN). Materials and Methods: Intraoperative and radiographic variables of 74 lower third molars were retrospectively analyzed. Intraoperative variables included IAN exposure, number of roots, root morphology of extracted third molars, and presence/absence of IAN impression on the root surface. Radiographic variables included presence/absence of the cortex separating IAN from the third molar roots on CBCT examination, number of roots and root morphology on both orthopantomography (OPG) and CBCT. The statistical association between variables was evaluated using the Fisher's exact test. Results: In all cases of intraoperative IAN exposure, the cortex appeared discontinuous on CBCT images. All cases, in which the cortical bone was continuous on CBCT images, showed no association with nerve exposure. In all cases in which nerve impression was identified on the root surface, the IAN cortex showed interruptions on CBCT images. No nerve impression was identified in any of the cases, in which the cortex appeared continuous on CBCT images. CBCT also highlighted accessory roots and apical anomalies/curvatures, not visible on the OPG. Conclusions: CBCT seems to provide reliable and accurate information about the third molar root morphology and its relationship with the IAN.

scholarly journals Designing and Fabricating Nano-Structured and Micro-Structured Radiation Shields for Protection against CBCT Exposure

Materials ◽  
2020 ◽  
Vol 13 (19) ◽  
pp. 4371 ◽  
Author(s):  
Kiana Nikeghbal ◽  
Zahra Zamanian ◽  
Shoaleh Shahidi ◽  
Gianrico Spagnuolo ◽  
Parisa Soltani
Keyword(s):  
Computed Tomography ◽  
Weight Ratio ◽  
Dioctyl Phthalate ◽  
Cone Beam ◽  
Linear Attenuation Coefficient ◽  
X Rays ◽  
X Ray ◽  
Nano Material ◽  
Radiation Shields ◽  
Shielding Properties

Researchers have always been interested in finding new and effective materials for protection against radiation. This experimental study aimed to design and fabricate new types of nano-material and micro-material based shields against the ionizing effect of cone beam computed tomography (CBCT) X-rays. To fabricate a flexible prototype, we added dioctyl phthalate (DOP) oil to emulsion polyvinyl chloride (PVC) powder. The paste was mixed and dispersed. Then, nano- and micro-powders of WO3 and Bi2O3 were added to the paste, with the weight ratio of 20% PVC, 20% DOP, and 60% nano- and micro-metals. Using an ultrasonic mixer, the polymer matrix and metals were mixed and a paste with a thick texture was developed. The resultant paste was poured into glass molds and the molds were then heated in an oven. After cooling, the resultant sheets were selected for further experiments. A CBCT unit and dosimeter were used to evaluate the characterization and X-ray shielding properties of the fabricated prototypes. The half-value layers (HVL) for nano-WO3, micro-WO3, nano-Bi2O3, and micro-Bi2O3 were 0.0390, 0.0524, 0.0351, and 0.0374 cm, respectively. In addition, the linear attenuation coefficient (µ) for these materials were 17.77, 13.20, 19.71, and 18.5 cm−1, respectively. The findings indicate that nano-structured samples are more effective in the attenuation of X-ray energy. The nano-structured WO3 prototype was nearly 34% more efficient in attenuating radiation compared to the micro-structured WO3 prototype. This difference in nano- and micro-structured Bi2O3 prototypes was 6.5%.

scholarly journals Association between imaging and clinical findings in mandibular third molar surgeries

2018 ◽  
Vol 23 (1) ◽  
Author(s):  
Marcelo Bonifácio da Silva Sampieri ◽  
Danilo Da Silva Correa ◽  
Francisca Lívia Parente Viana ◽  
Thaís Sumie Nozu Imada ◽  
Josfran Da Silva Ferreira Filho ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Cone Beam Computed Tomography ◽  
Statistical Significance ◽  
Third Molar ◽  
Panoramic Radiograph ◽  
Mandibular Canal ◽  
Clinical Findings ◽  
Cone Beam ◽  
The Third ◽  
Close Relationship

Objective: it is important to evaluate the position andestablish the third molar relationship with the mandibularcanal to minimize the risk of nerve injury and assistin planning the extraction of this tooth. The panoramicradiograph is the standard diagnostic tool for this purpose.However, if it indicates a close relationship betweenthe third molar and the mandibular canal, furtherinvestigation using cone beam computed tomography(CBCT) may be recommended to check the three-dimensionalrelationship between the tooth and the mandibularcanal. Thus, this study aimed to correlate the clinicalfindings (observed in third molar surgeries) to imagingfindings (observed in panoramic radiographs andCBCT). Subjects and method: after the extraction of 20mandibular third molars, the panoramic radiograph andthe cone beam computed tomography were analyzed.Then, the surgical findings were correlated to the imagefindings. Results: It was observed that the radiographicfinding type 2 (darkening of roots) observed in the panoramicradiograph presented a greater relation to theabsence of cortical bone between the mandibular canaland the third molar (CBCT finding), with statistical significance(p

scholarly journals Dosimetry of Critical Organs in Maxillofacial Imaging with Cone-beam Computed Tomography

2019 ◽  
Vol 9 (1Feb) ◽  
Author(s):  
R Ghanbarnezhad Farshi ◽  
A Mesbahi ◽  
M Johari ◽  
Ü Kara ◽  
N Gharehaghaji
Keyword(s):  
Computed Tomography ◽  
Cone Beam Computed Tomography ◽  
Cone Beam ◽  
Radiation Doses ◽  
Parotid Glands ◽  
Thermoluminescent Dosimeters ◽  
Wide Range ◽  
Significant Difference ◽  
The Mean ◽  
Selection Of

Background: While the benefits of cone-beam computed tomography (CBCT) are well known in maxillofacial imaging, the use of this modality is not risk-free.Objective: The aim of this study was to evaluate the exposure doses received by patients during maxillofacial imaging with CBCT.Methods: Entrance surface dose (ESD) was measured by using thermoluminescent dosimeters (TLDs) attached to the eyes lids, parotid glands and thyroid of 64 patients in two imaging centers (A and B). Phantom dosimetry was performed by a cylindrical poly-methyl methacrylate (PMMA) head-size phantom and an ionization chamber for different exposure parameters. NewTom VGi and Planmeca Promax 3D CBCT scanners were used at centers A and B, respectively.Results: The mean ESD of the eyes, parotid glands and thyroid were 2.57, 2.33 and 0.28 mGy in center A, 0.35, 2.11 and 0.37 mGy in center B, respectively. ESD of the eyes revealed a significant difference in two centers; in center B, it was 86.4% lower than center A. In the phantom dosimetry, the measured doses of NewTom VGi were 2.63 and 2.08 mGy, respectively by changing field of view (FOV) size from 8×8 cm2 (height × diameter) to 6×6 cm2. For Planmeca Promax 3D, it ranged from 0.98 to 3.24 mGy depending on exposure parameters.Conclusion: There is a wide range of radiation doses dependent on the units, patients and selected scan parameters. Inappropriate selection of exposure settings, especially FOV size, can seriously increase patient dose.

scholarly journals Prevalence of root canal system configurations in the brazilian population analyzed by cone-beam computed tomography – a systematic review

2021 ◽  
Vol 62 (2) ◽  
Author(s):  
Emmanuel Silva ◽  
◽  
Marina Prado ◽  
Marco Duarte ◽  
Marco Versiani ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Systematic Review ◽  
Cone Beam Computed Tomography ◽  
Root Canal ◽  
Cone Beam ◽  
Free Text ◽  
Prevalence Studies ◽  
Root Canals ◽  
Mesh Terms ◽  
Wide Range

Objectives: This study performed a systematic review of anatomy prevalence studies using cone-beam computed tomography to comprehend the root and root canal configuration types in Brazilian sub-populations. Methods: This systematic review followed PRISMA’s statements. Four electronic databases (PubMed, ScienceDirect, Lilacs, and Cochrane Collaboration) were accessed using MeSH terms and free-text keywords. The studies were selected according to predefined criteria. References of the collected studies, three peer-reviewed endodontic journals, and two peer-reviewed evidence-based dentistry journals were hand searched. The authors were contacted for additional information, if necessary. Eligible studies were submitted to a scientific merit assessment by two evaluators independently, who reached a final consensus for each study score using the Joanna Briggs Institute Critical Appraisal tool for prevalence studies. Results: A total of 2266 studies were identified. After analysis, 20 full-text articles were accessed for eligibility and 17 were included for qualitative synthesis. A high prevalence of mandibular incisors presenting two root canals was noted (~35.0% – 40.0). Moreover, a high proportion of two-rooted (17.0% – 28.4%) and two root canals (50.1% – 75.0%) morphologies were identified in maxillary second premolars. A wide range and a high percentage of a second mesiobuccal canal were detected for both maxillary first (37.1% – 88.5%) and second molars (21.8% – 83.4%). A second root canal prevalence ranging from 12.4% to 23.4% was observed in the distal root of mandibular first molars. Conclusions: In conclusion, different Brazilian sub-populations may present divergent characteristics regarding the root and root canal configurations. Clinicians should be aware of these variations for proper planning of endodontic treatment.

Typical errors when performing intraoral periapical x-rays, and their effect on image quality

2020 ◽  
pp. 36-44
Author(s):  
A.P. Arzhantsev
Keyword(s):  
Computed Tomography ◽  
Image Quality ◽  
Digital Image ◽  
Cone Beam ◽  
X Rays ◽  
Post Processing ◽  
X Ray ◽  
Selection Of ◽  
Periapical Radiography

During the study, intraoral periapical images were analyzed in 300 patients. The possibilities of using the methods of radiography and their influence on the quality of the obtained x-ray images were studied. The intraoral periapical radiography was compared with the results of orthopantomography and cone beam computed tomography. To identify the features of the mapping of zones of periapical destruction, 47 experimental x-ray studies were performed on skeletonized jaws with artificial defects in cortical plates. Often encountered errors are: an arbitrary choice of angles of inclination and the centration of the x-ray tube, the wrong location of the x-ray receiver in the patient's mouth, inaccurate installation or poor fixation of the patient's head, inefficient selection of physical and technical conditions of shooting, non-compliance with the conditions of the photo process with analog radiography or post-processing and printing digital image. The characteristic projection distortions of images resulting from these errors are analyzed and illustrated.

Visibility of Artificial Buccal Recurrent Caries Under Restorations Using Different Radiographic Techniques

2013 ◽  
Vol 38 (2) ◽  
pp. 197-207 ◽  
Author(s):  
S Murat ◽  
K Kamburoğlu ◽  
A İsayev ◽  
S Kurşun ◽  
S Yüksel
Keyword(s):  
Computed Tomography ◽  
Cone Beam Computed Tomography ◽  
Interobserver Agreement ◽  
Cone Beam ◽  
Thermoplastic Polymer ◽  
Intraoral Radiography ◽  
Class V ◽  
Significance Level ◽  
The Third ◽  
Nickel Chromium

SUMMARY The aim of the present study was to assess intraoral images and two cone beam computed tomography (CBCT) systems for detection of artificial buccal recurrent caries under restorations. Class V cavities were made for composite (30 teeth) and amalgam (30 teeth). Full restorations with thermoplastic polymer (30 teeth) and nickel-chromium metal crown (30 teeth) were constructed. In 60 teeth, artificial buccal recurrent caries were simulated; 60 other teeth served as controls. Intraoral film, intraoral digital, Veraviewepocs 3D, and Kodak 9000 images were scored twice. κ Coefficients were calculated and Az values were compared using Z-tests, with a significance level of α=0.05. Higher interobserver agreement was obtained from the CBCT images compared with the intraoral images. The Az values of both readings of all three observers were highest for the Veraviewepocs 3D followed by Kodak 9000 except for the second reading of the third observer. CBCT outperformed intraoral radiography in detection of artificial buccal recurrent caries under restorations.

scholarly journals Cone Beam Computed Tomography: Adding the Third Dimension

2012 ◽  
Vol 2 (3) ◽  
pp. 84-88 ◽  
Author(s):  
Rohit B Gadda ◽  
Rohini Salvi ◽  
Neha Anil Patil
Keyword(s):  
Computed Tomography ◽  
Cone Beam Computed Tomography ◽  
Cone Beam ◽  
Imaging Technology ◽  
The Third ◽  
Potential Applications ◽  
Third Dimension

ABSTRACT Cone beam computed tomography is a comparatively new threedimensional imaging technology, which has been specially developed for imaging of the maxillofacial complex. The aim of this paper is to accustom the dental fraternity with the wide and potential applications of cone beam computed tomography in dentistry. How to cite this article Patil NA, Gadda R, Salvi R. Cone Beam Computed Tomography: Adding the Third Dimension. J Contemp Dent 2012;2(3):84-88

Sign in / Sign up

Export Citation Format

Share Document