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1.
Diagnostics (Basel) ; 14(10)2024 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-38786307

RESUMO

Osteoporosis is often detected late and becomes severe because of a lack of subjective symptoms. Digital panoramic radiography (DPR) has been reported to be useful for osteoporosis screening based on the morphological classification of the mandibular inferior cortex. The purpose of this study was to evaluate the sensitivity and specificity of the mandibular cortical index (MCI) in the diagnosis of osteoporosis in a group of patients who were and were not using antiosteoporosis medication (AOM). Three hundred and fifty female patients aged 40 years or older who had DPR imaging performed during a 6-year period from December 2015 to February 2022 met the selection criteria. Two examiners recorded mandibular cortical width and MCI from the images. These results were statistically examined together with the patients' demographic data. Forty-nine patients were using AOM (13 nonbisphosphonate/denosumab and 36 bisphosphonate/denosumab). MCI type 3 was the most common in the AOM group. In the MCI classification, DPR imaging among the AOM group was more sensitive (0.95) than that of the control group. This method of estimating osteoporosis based on MCI classification using DPR images has high sensitivity, especially in patients using AOM, suggesting that this method is useful as a screening test.

2.
Dentomaxillofac Radiol ; 53(5): 308-315, 2024 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-38608191

RESUMO

OBJECTIVE: To compare digital panoramic radiography (DPR) and cone beam CT (CBCT) in the detection and classification of pulp calcifications in posterior teeth in relation to tooth condition and its location. METHODS: Two hundred and fifty patients with simultaneous DPR and CBCT scans were selected from a dental image bank. For each posterior tooth, its condition was registered (healthy, restored, or decayed). The presence of calcifications was assessed and classified according to location (coronal or radicular) and type (total obliteration, partial obliteration, narrowing, and no calcification). Chi-square and McNemar tests were used to compare DPR and CBCT results, with a significance level of 5%. DPR diagnostic values were calculated using CBCT as reference. RESULTS: Decayed and restored teeth showed a significantly (P < .001) higher prevalence of pulp calcifications than healthy teeth in both imaging exams. There was a significant discrepancy between the imaging modalities in the identification of calcifications (P < .001), especially for radicular calcifications of maxillary teeth (DPR = 55.2%; CBCT = 30.9%). In the case of coronal calcifications, there was a greater discrepancy between CBCT and DPR in the mandibular teeth (10.7%) than in the maxillary teeth (7.7%). Overall, DPR presents higher sensitivity (0.855) than specificity (0.483) for pulp calcifications detection. CONCLUSION: DPR considerably overestimates pulp calcifications in posterior teeth, as compared to CBCT. A higher prevalence of pulp calcifications is related to decayed and restored teeth.


Assuntos
Tomografia Computadorizada de Feixe Cônico , Calcificações da Polpa Dentária , Radiografia Dentária Digital , Radiografia Panorâmica , Humanos , Tomografia Computadorizada de Feixe Cônico/métodos , Feminino , Masculino , Calcificações da Polpa Dentária/diagnóstico por imagem , Adulto , Pessoa de Meia-Idade , Adolescente , Idoso , Dente Molar/diagnóstico por imagem
3.
Oral Radiol ; 40(3): 415-423, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38625432

RESUMO

OBJECTIVE: This study aimed to evaluate the usability of morphometric features obtained from mandibular panoramic radiographs in gender determination using machine learning algorithms. MATERIALS AND METHODS: High-resolution radiographs of 200 patients aged 20-77 (41.0 ± 12.7) were included in the study. Twelve different morphometric measurements were extracted from each digital panoramic radiography included in the study. These measurements were used as features in the machine learning phase in which six different machine learning algorithms were used (k-nearest neighbor, decision trees, support vector machines, naive Bayes, linear discrimination analysis, and neural networks). To evaluate the reliability, we have performed tenfold cross-validation and we repeated this 10 times for every classification process. This process enhances the reliability of the results for other datasets. RESULTS: When all 12 features are used together, the accuracy rate is found to be 82.6 ± 0.5%. The classification accuracies are also compared using each feature alone. Three features that give the highest accuracy are coronoid height (80.9 ± 0.9%), condyle height (78.2 ± 0.5%), and ramus height (77.2 ± 0.4%), respectively. When compared to the classification algorithms, the highest accuracy was obtained with the naive Bayes algorithm with a rate of 84.0 ± 0.4%. CONCLUSION: Machine learning techniques can accurately determine gender by analyzing mandibular morphometric structures from digital panoramic radiographs. The most precise results are achieved by evaluating the structures in combination, using attributes obtained from applying the MRMR algorithm to all features.


Assuntos
Aprendizado de Máquina , Mandíbula , Radiografia Panorâmica , Humanos , Feminino , Adulto , Pessoa de Meia-Idade , Masculino , Mandíbula/diagnóstico por imagem , Mandíbula/anatomia & histologia , Idoso , Reprodutibilidade dos Testes , Algoritmos , Determinação do Sexo pelo Esqueleto/métodos , Adulto Jovem , Teorema de Bayes
4.
Acta Odontol Scand ; 80(6): 419-426, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35015609

RESUMO

OBJECTIVE: Forensic examinations involve the identification of age and sex from living or mortal remains. The mandible comprises several growth parameters and is often recovered intact, making it an important tool for radiological identification. Therefore, the present study was conducted to determine the accuracy of various mandibular measurements on digital panoramic images in indicating sex and age in a subadult population. Methods: Panoramic images from 1,100 individuals (550 males, 550 females) ranging in age between 3 and 13 years were divided into 11 groups according to age. Ten mandibular linear dimensions (ramus height, condylar ramus height, coronoid ramus height, maximum ramus breadth, minimum ramus breadth, bigonial breadth, bicondylar breadth, bimental breadth, lateral length of mental foramen, vertical length of mental foramen) and gonial angle were measured bilaterally. Univariate discriminant and regression analyses were performed to determine the most significant predictors of sex and age. RESULTS: All linear dimensions were higher for males than females for all age groups. Gonial angle did not vary significantly by gender. Discriminant analysis showed linear measurements and gonial angle exhibited poor accuracy in sex determination. Despite a positive correlation between linear measurements and a negative correlation between gonial angle and age, the discriminant analysis found that age estimations made using all the recorded variables had an accuracy of only 66.72%. CONCLUSION: In line with previous research on different populations, findings for the selected subadult population sample showed that the growing mandible does not present sufficient sexual dimorphism to be useful for sex and age estimations.


Assuntos
Mandíbula , Caracteres Sexuais , Adolescente , Criança , Pré-Escolar , Análise Discriminante , Feminino , Humanos , Masculino , Mandíbula/diagnóstico por imagem , Radiografia
5.
Rev. odontol. UNESP (Online) ; 51: e20220050, 2022. tab, ilus
Artigo em Inglês | LILACS, BBO - Odontologia | ID: biblio-1424235

RESUMO

Abstract Introduction Osteoporosis is a metabolic disease characterized by reduced bone mineral density, often accompanied by loss of quality of trabecular bone microarchitecture. Objective To assess the quality or degradation of trabecular bone microarchitecture in digital panoramic radiography to better predict the risk of fragility fractures. Material and method The sample included 68 female patients, age-matched, and divided into three groups according to densitometric results. Trabecular Bone Score values were measured and digital panoramic radiographs were taken. Fractal analysis with box counting was conducted in the region of premolars and angle of the mandible, with regions of interest measuring 64×64 and 80×120 pixels. In the statistical analysis, Pearson's correlation was applied between the Trabecular Bone Score and fractal analysis results obtained in each group, using age as a control variable and assigning individualized age ranges within groups. Result A moderate correlation was identified in the regions of interest of 64×64 and 80×120 pixels at the angle of the mandible in the osteoporosis group and in the normal group. A moderate correlation was also obtained using age as a control variable in the 64x64 pixel regions of interest in the premolar region. Considering age range, the within-group analysis presented a strong correlation in the osteoporosis group and moderate correlation in the osteopenia and normal groups. Conclusion Fractal analysis in digital panoramic radiographs was shown to be a promising predictive instrument of bone microarchitecture quality.


Resumo Introdução A osteoporose é uma doença metabólica caracterizada pela redução da densidade mineral óssea, muitas vezes acompanhada da perda de qualidade da microarquitetura óssea trabecular. Objetivo Avaliar a qualidade da microarquitetura óssea trabecular em radiografia panorâmica digital a fim de identificar precocemente a sua degradação, possibilitando melhor predição do risco de fraturas por fragilidade. Material e método A amostra consistiu de 68 pacientes do sexo feminino, pareadas por idade, e divididas em 3 grupos conforme resultado densitométrico. Foram aferidos os valores de Trabecular Bone Score e realizadas radiografias panorâmicas digitais. A análise fractal com box counting foi feita na região de pré-molares e ângulo da mandíbula, com regiões de interesse medindo 64x64 e 80x120 pixels. Na análise estatística utilizou-se a correlação de Pearson entre os resultados de Trabecular Bone Score e de análise fractal obtidos em cada grupo, utilizando-se a idade como variável de controle e através de atribuição de grupos etários individualizados intragrupos. Resultado Identificou-se correlação moderada nas regiões de interesse de 64x64 e 80x120 pixels, em ângulo da mandíbula no grupo Osteoporose e no grupo normal. Também se obteve correlação moderada utilizando a idade como variável de controle nas regiões de interesse de 64x64 pixels, em região de pré-molares. A análise intragrupos, considerando a faixa etária, resultou em correlação forte, no grupo osteoporose e moderada nos grupos osteopenia e normal. Conclusão A análise fractal em radiografias panorâmicas digitais se mostrou promissora como instrumento preditivo da qualidade de microarquitetura óssea.


Assuntos
Humanos , Feminino , Osteoporose , Osso e Ossos , Doenças Ósseas Metabólicas , Radiografia Panorâmica , Mandíbula
6.
Turk J Orthod ; 34(1): 31-38, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33828876

RESUMO

OBJECTIVE: This study aimed to evaluate the relationship between the calcification stages of permanent maxillary and mandibular canines and second premolars and skeletal maturity in both sexes. METHODS: This study included 138 patients (82 females, 56 males) who were treated in the Department of Orthodontics, Altinbas University. The mean age of the patients was 12.31±1.76 years, ranging from 7.8 years to 15.8 years. Dental maturity stages of canines and second premolars were evaluated according to the Demirjian index on digital panoramic radiograph. The skeletal maturation stage was determined using the cervical vertebral maturation (CVM) index. The Pearson correlation analysis was performed to assess the association among CVM stages and calcification stages of canines, second premolars, sex, and chronological ages. RESULTS: A statistically significant correlation was found between CVM and the calcification stages of the canines and second premolars (p<0.05). The calcification stages of the canines and second premolars had the highest distribution of Stage F and Stage G at CVM2 (p<0.01). For the canines and second premolars, Stage H corresponded to CVM3 in female patients and a high percentage of Stage G corresponded to CVM3 in the male group. CONCLUSION: A significant correlation was found between the calcification stages of maxillary and mandibular canines, second premolars, and skeletal maturity in both sexes. It was observed that calcification stages and cervical maturations were advanced in female subjects compared with male subjects.

7.
Curr Health Sci J ; 45(2): 156-166, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31624642

RESUMO

INTRODUCTION: Root resorption is a pathological process characterized by loss of dental root substance, caused by bacterial infections, traumatic injuries or chemical irritation. Root resorption might be accidentally observed on digital panoramic radiography. OBJECTIVE: The objective of the study was to identify characteristic radiological aspects for the different types of root resorption that could be observed on digital panoramic radiography, to make an easier diagnostic of root resorption. MATERIAL AND METHOD: The retrospective study used the X-ray base from the Oral Rehabilitation and Dental Prosthetics Clinic of UMF Craiova to identify the most representative images for different types of root resorption. Digital panoramic radiographies were analysed by two investigators, of which the most suggestive images were selected and described. RESULTS: Digital panoramic radiographies and dental charts of 240 patients were analyzed. 113 cases of root resorption were identified. External inflammatory root resorption (EIRR) was present in 27.07% of studied cases, external cervical root resorption (ECRR) was identified in 10.83% of all studied cases, external replacement root resorption (ERRR) was diagnosed in 7.08% of studied cases and internal root resorption (IRR) was the most rare type of root resorption, with only 2.08% from all studied cases. 16 cases were selected to describe the radiologic features of different types of root resorption, featuring the most interesting images of root resorption evident on digital panoramic radiographies. DISCUSSION: Comparative analyses have been made between our results and the results of other specific studies, with both similar and different values. The radiological features which lead to the diagnostic of each type of RR were highlighted, assessing the causes that caused the lesions, as well as the treatment recommendations. CONCLUSIONS: Digital panoramic radiography is a useful tool to identify root resorption, since it has become the most common radiological investigation for diagnostic in dentistry. Description of radiological aspects of different types of root resorption on panoramic digital radiography allows faster diagnosis. Still, the CBCT may be recommended in some cases to confirm the diagnosis.

8.
Med Phys ; 46(11): 4907-4917, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31520417

RESUMO

PURPOSE: The digital panoramic radiography is widely used in dental clinics and provides the anatomical information of the intraoral structure along the predefined arc-shaped path. Since the intraoral structure varies depending on the patient, however, it is nearly impossible to design a common and static focal path or plane fitted to the dentition of all patients. In response, we introduce an imaging algorithm for digital panoramic radiography that can provide a focused panoramic radiographic image for all patients, by automatically estimating the best focal plane for each patient. METHODS: The aim of this study is to improve the image quality of dental panoramic radiography based on a three-dimensional (3D) dynamic focal plane. The plane is newly introduced to represent the arbitrary 3D intraoral structure of each patient. The proposed algorithm consists of three steps: preprocessing, focal plane estimation, and image reconstruction. We first perform preprocessing to improve the accuracy of focal plane estimation. The 3D dynamic focal plane is then estimated by adjusting the position of the image plane so that object boundaries in the neighboring projection data are aligned or focused on the plane. Finally, a panoramic radiographic image is reconstructed using the estimated dynamic focal plane. RESULTS: The proposed algorithm is evaluated using a numerical phantom dataset and four clinical human datasets. In order to examine the image quality improvement owing to the proposed algorithm, we generate panoramic radiographic images based on a conventional static focal plane and estimated 3D dynamic focal planes, respectively. Experimental results show that the image quality is dramatically improved for all datasets using the 3D dynamic focal planes that are estimated from the proposed algorithm. CONCLUSIONS: We propose an imaging algorithm for digital panoramic radiography that provides improved image quality by estimating dynamic focal planes fitted to each individual patient's intraoral structure.


Assuntos
Radiografia Dentária/métodos , Radiografia Panorâmica/métodos , Humanos , Imageamento Tridimensional , Razão Sinal-Ruído
9.
J Oral Maxillofac Pathol ; 22(2): 266-270, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30158784

RESUMO

BACKGROUND: The temporomandibular joint is a hinge joint which is formed by the mandible with articulation of the jaw with the cranium. The morphology of the mandible is evaluated by measuring the gonial angle ramus height and bigonial width. AIM: The aim of this study to investigate the impact of age and gender on ramus height, gonial angle and bigonial width in the dentulous odisha population using digital panaromic radiographs. MATERIALS AND METHODS: A total of 50 dentulous participants (25 males and 25 females) aged between 10 and 80 years were included in this study. The data were collected after comprehensive examination by 1 principal and two coinvestigators. STATISTICAL ANALYSIS: The mean difference between gender and different age groups was calculated using SPSS version 20.0. Unpaired t-test and one-way ANOVA were used for comparison studied parameters according to gender, side and different age groups followed by Tukey's post hoc test. RESULTS: A statistically significant gender difference was seen for gonial angle, ramus height and bigonial width. All the parameters increased with increase in age. This difference was statistically significant on the right side for gonial angle and ramus height. CONCLUSION: This study is useful as for age and sex determination using mandible as primary object in forensic odontology.

10.
Head Face Med ; 13(1): 2, 2017 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-28228135

RESUMO

BACKGROUND: Cone beam computerized tomography (CBCT) has been widely used in dental implanting. However, the local hospitals usually don't have access to CBCT due to the cost and medical investment, especially in West of China. The doctors in local hospitals have to make reasonable dental planting using orthopantomography (OPG) to reduce risks. Therefore, it is clinically meaningful to determine the magnification rate of OPG to obtain correct diagnosis. This study investigated the magnification rate of OPG in measuring different maxillofacial loci compared with CBCT. METHODS: Eighty-six patients demanding dental implanting were scanned by CBCT and OPG. The vertical distance between the alveolar ridge crest of the maxillary first molar and the sinus bottom of the upper jaw, the distance between the alveolar ridge crest of the mandibular first molars and the top of nerviduct in the mandibular alveolar, and the distance between the alveolar ridge crest of the maxillary central incisors and the bottoms of the nasal cavities were measured. The horizontal distance in those loci were also measured. The distances derived from CBCT were used as reference. The distances between the two methods were compared using paired t-test. The magnification rates at these positions were calculated. The relationship between the data acquired from the two methods was analyzed Pearson correlation. RESULTS: The correlation coefficients (R) between the paired samples obtained from OPG and CBCT were highly related (P < 0.05) with R values varying from 0.840 and 0.959 in vertical distances and R values varying from 0.703 and 0.904 in horizontal distances. Compared with data obtained from CBCT, the mean vertical magnification rates were 11.38% and 12.95% vertically and 8.55% and 9.43% horizontally for the first molars in the right and left maxilla respectively; 7.26% and 6.35% vertically and 5.33% and 4.96% horizontally for the first molars in the right and left mandible respectively; and 5.55% and 4.84% vertically and 6.53% and 7.47% horizontally for the central incisors in the upper right and left jaws respectively. CONCLUSION: The magnification rates of OPG at these teeth are different. The distances measured by OPG were highly correlated with that measured by CBCT.


Assuntos
Processo Alveolar/diagnóstico por imagem , Tomografia Computadorizada de Feixe Cônico/métodos , Implantes Dentários , Radiografia Panorâmica/métodos , Adolescente , Adulto , Idoso , China , Estudos de Coortes , Implantação Dentária/efeitos adversos , Implantação Dentária/métodos , Feminino , Humanos , Masculino , Mandíbula/diagnóstico por imagem , Mandíbula/cirurgia , Maxila/diagnóstico por imagem , Maxila/cirurgia , Pessoa de Meia-Idade , Análise de Regressão , Estudos Retrospectivos , Sensibilidade e Especificidade , Adulto Jovem
11.
Gen Dent ; 63(6): e5-e10, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26545285

RESUMO

This research aimed to compare the efficacy of digital panoramic radiography (DPR) with that of cone beam computed tomography (CBCT) for delineation of odontogenic and nonodontogenic tumors. From November 2009 through March 2011, 23 tumors in the maxillomandibular complex were diagnosed by histopathological examination. All DPRs and CBCTs were obtained and analyzed by a single previously calibrated radiologist, who considered the following radiographic aspects: clarity of the lesion edges, relation with dental elements, involvement of adjacent anatomical structures, cortical bone expansion and disruption, and, if present, type of involved anatomical structures and site of bone expansion and disruption. Of 23 patients, 15 (65.2%) were male and 8 (34.8%) were female. The tumor was classified as odontogenic in 73.9% of patients and nonodontogenic in 26.1% of patients. Analysis revealed that 56.5% of the tumors were located in the mandible, 34.8% in the maxilla, and 8.7% in both arches. For all analyzed variables, CBCTs offered more accurate details than did DPRs. Panoramic radiography should not be the examination of choice to visualize lesions in the maxillomandibular complex.


Assuntos
Tomografia Computadorizada de Feixe Cônico , Neoplasias Mandibulares/diagnóstico por imagem , Neoplasias Maxilares/diagnóstico por imagem , Radiografia Panorâmica , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Estudos Transversais , Feminino , Humanos , Masculino , Neoplasias Mandibulares/patologia , Neoplasias Maxilares/patologia , Pessoa de Meia-Idade , Tumores Odontogênicos/diagnóstico por imagem , Radiografia Panorâmica/métodos , Adulto Jovem
12.
J Clin Diagn Res ; 9(9): ZC90-2, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26501021

RESUMO

BACKGROUND: Eagle's syndrome comprises a rare disorder caused by compression of an elongated or deformed styloid process or ossified/calcified stylohyoid ligament on neural and vascular structures. It is characterized by facial and neck pain and can be confused with a wide variety of facial neuralgias, oral and dental diseases and temporomandibular disorders. An imaging evaluation associated with a careful clinical examination, are mandatory in structuring a correct differential diagnosis and in the establishment of a proper therapeutic protocol. AIM: To investigate the prevalence of the elongated styloid process in a Central Brazilian population and its relation to gender, age and side. MATERIALS AND METHODS: Digital panoramic radiographs of 736 patients (412 female and 324 male, with a mean age of 35.03 years) were consecutively selected from a private radiology clinic's secondary database. The apparent length of the styloid process was measured from the point where the styloid left the tympanic plate to the tip of the process by two specialists in dental radiology, with the help of the measuring tools on the accompanying software. Styloid process measuring more than 30 mm was considered elongated. The statistical analysis included frequency distribution and cross tabulation. The data were analysed by using Chi-squared tests. The level of significance was set at 5% for all analyses. RESULTS: A total of 323 (43.89%) radiographic images were suggestive of elongated styloid process. No statistically significant difference was found between the genders, although a higher prevalence was noticed in female participants. Approximately, 31% of the elongated styloid process was observed in 18-53-year-old participants (p < 0.05). Two hundred and sixty seven styloid processes (36.28%) were elongated on both right and left sides. CONCLUSION: The prevalence of elongated styloid process was high and no statistically significant correlation was found between the presence of elongated styloid process and the studied variables with the exception of the age.

13.
Clin Oral Implants Res ; 25(6): 690-5, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23442085

RESUMO

OBJECTIVES: To compare the implant size (width and length) planned with digital panoramic radiographs, cone beam computed tomography (CBCT)-generated panoramic views, or CBCT cross-sectional images, in four implant systems. MATERIAL AND METHODS: Seventy-one patients with a total of 103 implant sites in the upper premolar and/or lower molar regions were examined with digital panoramic radiography (D-PAN) and (CBCT). A metal ball 5 mm in diameter was placed in the edentulous area for the D-PAN. CBCT data sets were reformatted to a 10-mm thick CBCT panoramic view (CBCT-pan) and 1-mm cross-sections (CBCT-cross). Measurements were performed in the images using dedicated software. All images were displayed on a monitor and assessed by three observers who outlined a dental implant by placing four reference points in the site of the implant-to-be. Differences in width and length of the implant-to-be from the three modalities were analyzed. The implant size selected in the CBCT-cross images was then compared to that selected in the other two modalities (D-PAN and CBCT-pan) for each of the implant systems separately. RESULTS: The implant-to-be (average measurements among observers) was narrower when measured in CBCT-cross compared with both D-PAN and CBCT-Pan. For premolar sites, the width also differed significantly between D-PAN and CBCT-pan modalities. The implant-to-be was also significantly shorter when recorded in CBCT-cross than in D-PAN. In premolar sites, there were no significant differences in implant length among the three image modalities. It mattered very little for the change in implant step sizes whether CBCT-cross was compared to D-PAN or CBCT-pan images. CONCLUSION: Our results show that the selected implant size differs when planned on panoramic or cross-section CBCT images. In most cases, implant size measured in cross-section images was narrower and shorter than implant size measured in a panoramic image or CBCT-based panoramic view.


Assuntos
Tomografia Computadorizada de Feixe Cônico , Implantação Dentária Endóssea , Implantes Dentários , Planejamento de Prótese Dentária , Planejamento de Assistência ao Paciente , Radiografia Panorâmica , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Cuidados Pré-Operatórios , Software
14.
Dentomaxillofac Radiol ; 42(9): 20130265, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24005060

RESUMO

OBJECTIVES: To evaluate the shielding effect of thyroid collar for digital panoramic radiography. METHODS: 4 machines [Orthopantomograph(®) OP200 (Instrumentarium Dental, Tuusula, Finland), Orthophos CD (Sirona Dental Systems GmbH, Bensheim, Germany), Orthophos XG Plus (Sirona Dental Systems GmbH) and ProMax(®) (Planmeca Oy, Helsinki, Finland)] were used in this study. Average tissue-absorbed doses were measured using thermoluminescent dosemeter chips in an anthropomorphic phantom. Effective organ and total effective doses were derived according to the International Commission of Radiological Protection 2007 recommendations. The shielding effect of one collar in front and two collars both in front and at the back of the neck was measured. RESULTS: The effective organ doses of the thyroid gland obtained from the 4 panoramic machines were 1.12 µSv for OP200, 2.71 µSv for Orthophos CD, 2.18 µSv for Orthophos XG plus and 2.20 µSv for ProMax, when no thyroid collar was used. When 1 collar was used in front of the neck, the effective organ doses of the thyroid gland were 1.01 µSv (9.8% reduction), 2.45 µSv (9.6% reduction), 1.76 µSv (19.3% reduction) and 1.70 µSv (22.7% reduction), respectively. Significant differences in dose reduction were found for Orthophos XG Plus and ProMax. When two collars were used, the effective organ doses of the thyroid gland were also significantly reduced for the two machines Orthophos XG Plus and ProMax. The same trend was observed in the total effective doses for the four machines. CONCLUSIONS: Wearing a thyroid collar was helpful when the direct digital panoramic imaging systems were in use, whereas for the indirect digital panoramic imaging systems, the thyroid collar did not have an extra protective effect on the thyroid gland and whole body.


Assuntos
Imagens de Fantasmas , Lesões por Radiação/prevenção & controle , Proteção Radiológica/instrumentação , Radiografia Dentária Digital , Radiografia Panorâmica , Glândula Tireoide/efeitos da radiação , Análise de Variância , Humanos , Masculino , Pescoço/efeitos da radiação , Radiografia Dentária Digital/instrumentação , Radiografia Panorâmica/instrumentação , Dosimetria Termoluminescente
15.
Int. j. odontostomatol. (Print) ; 4(3): 207-213, dic. 2010. tab, ilus
Artigo em Inglês | LILACS | ID: lil-594256

RESUMO

The increase in the number of surgical procedures in the mandibular region requires a new perspective into anatomical landmarks such as the mandibular canal and its imagenological aspect. The present study aimed to determine the prevalence of the alterations in the number of mandibular canals in digital panoramic images obtained from patients of a private radiological center of the Maule region. The study period was from March to December 2008. A total of 350 panoramic digital X-ray images were analyzed by examining them for hemi-mandibles (n = 700) and quantifying the alterations of the number of mandibular canal. There were 35 cases of bifurcations to the mandibular canal, corresponding to 5 percent of the sample in the study. The obtained information indicates a major prevalence described by the literature, which reinforces the need of a larger study of the radiographic images of the mandibular canal, considering the difficult managing of a surgical complication on this anatomical structure.


El aumento de los procedimientos quirúrgicos realizados en la región mandibular requiere dar una nueva mirada a los reparos anatómicos como el canal mandibular y su aspecto imagenológico. El presente estudio tuvo como propósito determinar la prevalencia de las alteraciones de número del canal mandibular en imágenes panorámicas del período de marzo a diciembre de 2008, obtenidas de pacientes de un centro radiológico privado de la región del Maule. Para el efecto se analizaron 350 radiografías panorámicas digitales, examinándolas por hemiarcada (n = 700) y cuantificando las alteraciones de número del canal mandibular. Se encontraron 35 casos de bifurcaciones de canal mandibular correspondientes al 5 por ciento de la muestra en estudio. Los datos obtenidos indican una prevalencia mayor a la descrita por la literatura, lo que refuerza la necesidad de un estudio acabado de las imágenes radiográficas del canal mandibular, considerando el difícil manejo de una complicación quirúrgica sobre esta estructura anatómica.


Assuntos
Humanos , Masculino , Adolescente , Feminino , Mandíbula/anormalidades , Mandíbula , Nervo Mandibular , Radiografia Panorâmica , Chile/epidemiologia , Mandíbula/inervação , Nervo Mandibular/anatomia & histologia , Prevalência
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