Effect of dental distance from implant and MAR algorithm on the detection of vertical root fracture in CBCT images

Three-dimensional cone-beam computed tomography (CBCT) has an important role in the detection of vertical root fractures (VRFs). The effect of artifact generation by high-density objects like dental implants on image quality was well documented. This study aimed to assess the effect of tooth-implant distance and the application of metal artifact reduction (MAR) algorithm on the detection of VRFs on CBCT scans. This study was conducted on 20 endodontically treated single-rooted teeth. VRFs were induced in 10 teeth, while the other 10 remained intact. The implant was inserted in the right second premolar socket area, and two teeth were inserted in right canine and right first premolar sockets area randomly and underwent CBCT with and without the application of MAR algorithm. SPSS 21 was used to analyze the results (alpha=0.05). According to the findings of this study, all four variables of sensitivity, specificity, accuracy, and positive predictive values in diagnosis were higher in cases without MAR software at both close(roots in first premolar sockets) and far distances (roots in canine sockets) from the implant. However, the highest rate of diagnosis accuracy of the first and second radiologists was in the far distance group from the implant without MAR, and the lowest rate of diagnosis accuracy in the first and second radiologists was in the close distance to the implant. Applying MAR algorithm had no positive effect on detection of VRFs on CBCT scans in both close and distant scenarios.

La tomografía computarizada de haz cónico tridimensional (CBCT) tiene un papel importante en la detección de fracturas radiculares verticales (VRF). El efecto de la generación de artefactos por objetos de alta densidad como los implantes dentales en la calidad de la imagen está bien documentado. Este estudio tuvo como objetivo evaluar el efecto de la distancia entre el diente y el implante y la aplicación del algoritmo de reducción de artefactos metálicos (MAR) en la detección de VRF en escaneos CBCT. Este estudio se realizó en 20 dientes uniradiculares tratados endodónticamente. Se indujeron VRF en 10 dientes, mientras que los otros 10 permanecieron intactos. El implante se insertó en el área del alveolo del segundo premolar derecho, y dos dientes se insertaron en el canino derecho y en el área del alvéolo del primer premolar derecho al azar y se sometieron a CBCT con y sin la aplicación del algoritmo MAR. Se utilizó SPSS 21 para analizar los resultados (alfa=0,05). De acuerdo con los hallazgos de este estudio, las cuatro variables de sensibilidad, especificidad, precisión y valores predictivos positivos en el diagnóstico fueron más altas en los casos sin el software MAR tanto en distancias cercanas (raíces en las cavidades de los primeros premolares) como lejanas (raíces en las cavidades de los caninos) del implante. Sin embargo, la tasa más alta de precisión diagnóstica del primer y segundo radiólogo fue en el grupo de mayor distancia al implante sin MAR, y la tasa más baja de precisión diagnóstica en el primer y segundo radiólogo fue en la distancia cercana al implante. La aplicación del algoritmo MAR no tuvo un efecto positivo en la detección de VRF en escaneos CBCT en escenarios cercanos y distantes.

Anatomical Variations of the Mandibular Symphysis in a Normal Occlusion Population Using Cone-Beam Computed Tomography.

This study aimed to assess the anatomical variations of the mandibular symphysis in a normal occlusion population using cone-beam computed tomography (CBCT). This retrospective cross-sectional study evaluated 200 CBCT scans of patients aged ≥17 with class I occlusion, 1-3 mm overbite and overjet, and <3 mm crowding. The CBCT scans were obtained with NewTom 3G scanner with the exposure settings of 110 kVp, 1.2 mA, 5.4 s time, and six-inch field of view and saved in NNT Viewer. The anterior loop length, labial bone thickness, mandibular bone height at the symphysis, and cortical bone thickness at the right and left canine teeth and central and lateral incisors were measured and compared between males and females and different age groups using one-way ANOVA. The intra- and inter-observer agreements for all landmarks were ICC >0.9 (excellent). The mean length of the anterior loop in females was significantly greater than that in males (P=0.02). Different age groups had significant differences in cortical bone width at the site of the left canine (P=0.03) and vertical bone height at the site of the right central incisor (P=0.05). The majority of parameters related to the mandibular symphysis were greater in normal occlusion males than females. Preoperative CBCT assessment of the mandibular symphysis can greatly help in diagnosis and treatment planning as well as bone harvesting from this area.

Appearance of Mandibular Para-radicular Third Molar Radiolucencies on Cone-Beam Computed Tomography.

AIMS: Mandibular para-radicular third molar radiolucencies (MPRs) may be mistaken for pathological lesions, leading to misdiagnosis and mistreatment. This study sought to assess the appearance of MPRs on cone-beam computed tomography (CBCT). SETTINGS AND DESIGN: This was a descriptive, cross-sectional study. MATERIALS AND METHODS: This study evaluated 770 CBCT of patients presenting to the dental school of Hamadan University of Medical Sciences. Demographic information, unilateral or bilateral presence, shape and prevalence of MPRs observed on axial and sagittal sections, their density, thinning of cortical margin, internal trabeculation, bony expansion, and mean height and width of MPRs were all evaluated. STATISTICAL ANALYSIS USED: Data were analyzed using SPSS version 22.0 and descriptive statistics. Chi-square test was used. RESULTS: Seventy (9.1%) patients had a total of 82 MPRs, including 51 (72.86%) females. The prevalence of MPRs in females was more than males (P = 0.011). The majority of MPRs were unilateral 58 (70.73%), mostly round in shape 48 (58.54%), and were mostly associated with third molars with distoangular impaction 47 (57.31%); this difference was statistically significant (P < 0.001). Furthermore, in 47 (57.32%) patients, MPRs had less density than the surrounding bone. MPRs were not associated with expansion or root resorption in any patient. CONCLUSION: Differentiation of MPRs from the pathological lesions is important to make a decision about further imaging or referral for surgical treatment. MPRs are often considered normal since they do not cause root resorption or bone expansion and do not affect the lamina dura. MPRs are more commonly found adjacent to third molars with distoangular impaction.

Morphometric analysis of the inter-mastoid triangle for sex determination: Application of statistical shape analysis.

PURPOSE: Sex determination can be done by morphological analysis of different parts of the body. The mastoid region, with its anatomical location at the skull base, is ideal for sex identification. Statistical shape analysis provides a simultaneous comparison of geometric information on different shapes in terms of size and shape features. This study aimed to investigate the geometric morphometry of the inter-mastoid triangle as a tool for sex determination in the Iranian population. MATERIALS AND METHODS: The coordinates of 5 landmarks on the mastoid process on the 80 cone-beam computed tomographic images (from individuals aged 17-70 years, 52.5% female) were registered and digitalized. The Cartesian x-y coordinates were acquired for all landmarks, and the shape information was extracted from the principal component scores of generalized Procrustes fit. The t-test was used to compare centroid size. Cross-validated discriminant analysis was used for sex determination. The significance level for all tests was set at 0.05. RESULTS: There was a significant difference in the mastoid size and shape between males and females (P<0.05). The first 2 components of the Procrustes shape coordinates explained 91.3% of the shape variation between the sexes. The accuracy of the discriminant model for sex determination was 88.8%. CONCLUSION: The application of morphometric geometric techniques will significantly impact forensic studies by providing a comprehensive analysis of differences in biological forms. The results demonstrated that statistical shape analysis can be used as a powerful tool for sex determination based on a morphometric analysis of the inter-mastoid triangle.

Efficacy of Metal Artifact Reduction Algorithm of Cone-Beam Computed Tomography for Detection of Fenestration and Dehiscence around Dental Implants.

BACKGROUND: Beam hardening and scattering artifacts from high-density objects such as dental implants adversely affect the image quality and subsequently the detection of fenestration or dehiscence around dental implants. OBJECTIVE: This study aimed to assess the efficacy of metal artifact reduction (MAR) algorithm of two cone-beam computed tomography (CBCT) systems for detection of peri-implant fenestration and dehiscence. MATERIAL AND METHODS: In this experimental study, thirty-six titanium implants were placed in bone blocks of bovine ribs. Fenestration and dehiscence were created in the buccal bone around implants. CBCT images were obtained using Cranex 3D and ProMax 3D CBCT systems with and without MAR algorithm. Two experienced radiologists observed the images. Data were analyzed using SPSS software. The Kappa coefficient of agreement, the area under the receiver operating characteristic (ROC) curve, sensitivity, specificity, and accuracy of different imaging modalities were calculated and analyzed. RESULTS: In both CBCT systems, the use of MAR algorithm decreased the area under the ROC curve and subsequently the diagnostic accuracy for the detection of fenestration and dehiscence. The sensitivity, specificity and accuracy of both CBCT systems were higher in absence of the MAR algorithm. The specificity of ProMax 3D for detection of fenestration was equal with/without the MAR algorithm. CONCLUSION: Although CBCT is suitable for detection of peri-implant defects, the application of the MAR algorithm does not enhance the detection of peri-implant fenestration and dehiscence.

Sex determination by osteometric assessment of the mastoid process using Cone Beam Computed Tomography / Determinação do sexo em uma população Iraniana por avaliação osteométrica do processo mastóide em imagens de TCFC

Objective: Sex determination is one of the most important parameters to identify in forensic science. Because the mastoid process is the most resistant to damage due to its position in the skull base, it can be used for sex determination. The purpose of this study was to measure the dimensions and convexity and internal angles of the mastoid process to present a model of sex determination in Iranian population. Material and methods: This study was performed on three-dimensional images of 190 Cone Beam Computed Tomography (CBCT) of 105 women and 85 men. On each CBCT the distance between the porion and the mastoid (PM), mastoid length (ML), the distance between the mastoidale and the mastoid incision (M-I), the mastoid height (MH), the mastoid width (MW), intermastoidale distance (IMD) the lateral surfaces of the left and right mastoids (IMLSD) and the Mastoid medial convergence angle (MMCA) was measured on both the right and the left. The data were analyzed by descriptive statistics, t-test, and discriminant function analysis. Results: Significant differences were found for all variables except MMCA and MF in both sex. All measured variables except MW were greater for men than women. The discriminant model achieved a total accuracy of 93.7%. Among the measured factors IMD and IMSLD had the most influence on sex determination. Conclusion: Measuring the dimensions of the mastoid process is a very good method for sex determination with high accuracy of 90% (AU)

Objetivo: A determinação do sexo é um dos parâmetros mais importantes para identificação na ciência forense. Por ser o processo mastóide resistente a danos, devido a sua posição na base do crânio, este poderia ser usado na determinação do sexo. O objetivo deste estudo foi mensurar as dimensões, convexidade e ângulos internos do processo mastóide para apresentar um modelo de determinação do sexo em uma população Iraniana. Material e métodos: Este estudo foi realizado em 190 imagens de tomografia computadorizada de feixe cônico (TCFC), sendo 105 mulheres e 85 homens. Em cada TCFC foram realizadas medidas no processo mastóide em comprimento (ML), altura (MH), largura (MW) em ambos os lados direito e esquerdo, também foi medida a distância entre o Pórion e o processo mastóide (PM), distância até incisura mastoidea (M-I), distância entre as superfícies mediais (IMD) distância entre as superfícies laterais dos processos direito e esquerdo (IMLSD) e o ângulo de convergência medial (MMCA). Os dados foram analisados por estatística descritiva, teste t e análise de função discriminante. Resultados: Diferenças significativas foram encontradas para todas as variáveis, exceto MMCA e MF em ambos os sexos. Todas as variáveis medidas, exceto MW, foram maiores para os homens do que para as mulheres. O modelo de análise de função discriminante alcançou uma precisão total de 93,7%. Entre os fatores medidos, o IMD e o IMSLD tiveram a maior influência na determinação do sexo. Conclusão: Podemos concluir que as dimensões do processo mastóide constituem um método para determinação do sexo, em população Iraniana, com precisão de 90% (AU)

Knowledge level of Iranian dental practitioners towards digital radiography and cone-beam computed tomography / Nível de conhecimento de dentistas Iranianos sobre Radiografia Digital e Tomografia Computadorizada de Feixe Cônico

Objective: TThis study aimed to assess the knowledge level of Iranian dental practitioners about digital radiography (DR) and cone-beam computed tomography (CBCT). Material and Methods: In this cross-sectional study, a researcher-designed questionnaire was administered among 180 general dentists and specialists. The questionnaire had three main domains of demographic information, fifteen questions about knowledge of DR (advantages, disadvantages, physical properties) and twenty six questions about knowledge of CBCT (indications, applications, advantages, route of knowledge acquisition). Data were analyzed using descriptive statistics, t-test and Pearson's correlation coefficient. Results: Of 180 participants, 76 (42.2%) were females. The minimum, maximum and mean± standard deviation scores obtained in DR were 4, 14, and 9.031 ± 1.85 and in CBCT were 0,26 and 18.56 ± 4.81, respectively. In the CBCT domain, the participants had maximum knowledge about "low radiation dose" (72.8%) and minimum knowledge about the "role of CBCT in determination of bone density" (45%). In DR domain, the participants had maximum knowledge about "no need for radiographic films" (75.6%) and minimum knowledge about "not requiring manual processing" (15.6%). Overall, participants had higher level of knowledge about CBCT than DR. An inverse correlation was noted between age and work experience with the number of correct answers. However, no significant difference was noted in the knowledge level of males and females regarding CBCT or DR (p = 0.233 and p = 0.227, respectively). Conclusions: further education seem imperative for dentists in this respect for more efficient diagnosis and treatment planning, minimize patient radiation dose and save time and cost. (AU)

Objetivos: Avaliar o nível de conhecimento de dentistas iranianos sobre radiografia digital (RD) e tomografia computadorizada de feixe cônico (TCFC). Materiais e métodos: Neste estudo transversal, um questionário, elaborado por pesquisadores, foi aplicado a 180 dentistas clínicos geral e especialistas. O questionário tinha três domínios principais de informação demográfica, quinze questões sobre conhecimento de RD (vantagens, desvantagens, propriedades físicas) e vinte e seis questões sobre conhecimento de CBCT (indicações, aplicações, vantagens, protocolo de aquisição). Os dados foram analisados por meio de estatística descritiva, teste t e coeficiente de correlação de Pearson. Resultados: Dos 180 participantes, 76 (42,2%) eram do sexo feminino. Os escores mínimo, máximo e média ± desvio padrão obtidos na RD foram 4, 14 e 9,031 ± 1,85 e na CBCT foram 0, 26 e 18,56 ± 4,81, respectivamente. No domínio CBCT, os participantes tinham conhecimento máximo sobre "baixa dose de radiação" (72,8%) e conhecimento mínimo sobre o "papel da CBCT na determinação da densidade óssea" (45%). No domínio RD, os participantes possuíam conhecimento máximo sobre "não há necessidade de filmes radiográficos" (75,6%) e conhecimento mínimo sobre "não requer processamento manual" (15,6%). No geral, os participantes tinham maior nível de conhecimento sobre CBCT do que RD. Foi observado correlação inversa entre idade e experiência de trabalho com o número de acertos. No entanto, nenhuma diferença significativa foi observada no nível de conhecimento de homens e mulheres sobre TCFC ou RD (p = 0,233 e p = 0,227 respectivamente). Conclusão: Parece imperativo para os dentistas iranianos, mais educação nesse aspecto para diagnóstico e planejamento de tratamento mais eficientes, minimizar a dose de radiação para paciente, economizar tempo e custos. (AU)

Anatomical variations of the maxillary sinus septa of an Iranian population using cone-beam computed tomography: a retrospective study / Variaciones anatómicas de los tabiques del seno maxilar de una población iraní mediante tomografía computarizada de haz cónico: estudio retrospectivo

This study sought to assess the internal anatomy of the maxillary sinuses and their septa using cone-beam computed tomography (CBCT) in an Iranian population. Materials and Methods: Resorption of alveolar bone decreases the height of the maxillary alveolar ridge. This height reduction may be so severe that it warrants ridge augmentation by a sinus lift. Manipulation of the maxillary sinuses, as in sinus lift surgery, requires adequate knowledge about the sinus anatomy.Results: Maxillary sinus septum, as an anatomical variation, may complicate the surgical procedures and increase the risk of complications such as sinus membrane perforation. In this retrospective study, 366 sinuses, 190 from females and 176 from males, aged between 10 and 65 years old presenting to the Oral and Maxillofacial Radiology Department of School of Dentistry at Hamadan University of Medical Sciences were evaluated by two oral radiologists. The extension of the maxillary sinuses, presence of septa, number of septa and their location were determined. Data were analyzed using the chi square test (level of significance p≤0.001). The coefficient of agreement between the two oral radiologists was calculated based on Cohen kappa. Septa were present in 40.5% of the maxillary sinuses, out of which, 31.6% had one, 7.9% had two and 1% had three or more septa; 38% of the septa were horizontal while 62% had an oblique orientation. In total, 184 septa were found in 183 patients; out of which, 91 septa were 2mm to 5mm long while 93 septa were longer than 5mm. Conclusions: Comprehensive knowledge about the three-dimensional internal anatomy of the maxillary sinuses acquired by CBCT priorto surgical procedures can greatly help to prevent postoperative complications.

Este estudio buscó evaluar la anatomía interna de los senos maxilares y sus septos mediante tomografía computarizada de haz cónico (CBCT) en una población Iraní. Materiales y Métodos: . La resorción del hueso alveolar disminuye la altura de la cresta alveolar maxilar. Esta reducción de altura puede ser tan severa que justifique el aumento de la cresta mediante una elevación de seno. La manipulación de los senos maxilares, como en la cirugía de elevación del seno, requiere un conocimiento adecuado sobre la anatomía del seno. Resultado: El tabique del seno maxilar, como una variación anatómica, puede complicar los procedimientos quirúrgicos y aumentar el riesgo de complicaciones como la perforación de la membrana sinusal. En este estudio retrospectivo, dos radiólogos orales evaluaron 366 senos, 190 de mujeres y 176 de hombres, con edades comprendidas entre 10 y 65 años que se presentaron en el Departamento de Radiología Oral y Maxilofacial de la Facultad de Odontología de Hamadan University of Medical Sciences. Se determinó la extensión de los senos maxilares, la presencia de septos, el número de septos y su ubicación. Los datos se analizaron mediante la prueba de chi cuadrado (nivel de significación p?0.001). El coeficiente de concordancia entre los dos radiólogos orales se calculó en base a Cohen kappa. Los septos estaban presentes en el 40.5% de los senos maxilares, de los cuales, el 31.6% tenía uno, el 7.9% tenía dos y el 1% tenía tres o más septos; El 38% de los septos eran horizontales, mientras que el 62% tenía una orientación oblicua. En total, se encontraron 184 septos en 183 pacientes; de los cuales, 91 septos tenían de 2mm a 5mm de largo, mientras que 93 septos tenían más de 5mm. Conclusion: El conocimiento exhaustivo sobre la anatomía interna tridimensional de los senos maxilares adquiridos por CBCT antes de los procedimientos quirúrgicos puede ayudar en gran medida a prevenir complicaciones postoperatorias.

Comparison of data mining algorithms for sex determination based on mastoid process measurements using cone-beam computed tomography.

PURPOSE: The mastoid region is ideal for studying sexual dimorphism due to its anatomical position at the base of the skull. This study aimed to determine sex in the Iranian population based on measurements of the mastoid process using different data mining algorithms. MATERIALS AND METHODS: This retrospective study was conducted on 190 3-dimensional cone-beam computed tomographic (CBCT) images of 105 women and 85 men between the ages of 18 and 70 years. On each CBCT scan, the following 9 landmarks were measured: the distance between the porion and the mastoidale; the mastoid length, height, and width; the distance between the mastoidale and the mastoid incision; the intermastoid distance (IMD); the distance between the lowest point of the mastoid triangle and the most prominent convex surface of the mastoid (MF); the distance between the most prominent convex mastoid point (IMSLD); and the intersecting angle drawn from the most prominent right and left mastoid point (MMCA). Several predictive models were constructed and their accuracy was compared using cross-validation. RESULTS: The results of the t-test revealed a statistically significant difference between the sexes in all variables except MF and MMCA. The random forest model, with an accuracy of 97.0%, had the best performance in predicting sex. The IMSLD and IMD made the largest contributions to predicting sex, while the MMCA variable had the least significant role. CONCLUSION: These results show the possibility of developing an accurate tool using data mining algorithms for sex determination in the forensic framework.

Dental age estimation using the pulp-to-tooth ratio in canines by neural networks.

PURPOSE: It has been proposed that using new prediction methods, such as neural networks based on dental data, could improve age estimation. This study aimed to assess the possibility of exploiting neural networks for estimating age by means of the pulp-to-tooth ratio in canines as a non-destructive, non-expensive, and accurate method. In addition, the predictive performance of neural networks was compared with that of a linear regression model. MATERIALS AND METHODS: Three hundred subjects whose age ranged from 14 to 60 years and were well distributed among various age groups were included in the study. Two statistical software programs, SPSS 21 (IBM Corp., Armonk, NY, USA) and R, were used for statistical analyses. RESULTS: The results indicated that the neural network model generally performed better than the regression model for estimation of age with pulp-to-tooth ratio data. The prediction errors of the developed neural network model were acceptable, with a root mean square error (RMSE) of 4.40 years and a mean absolute error (MAE) of 4.12 years for the unseen dataset. The prediction errors of the regression model were higher than those of the neural network, with an RMSE of 10.26 years and a MAE of 8.17 years for the test dataset. CONCLUSION: The neural network method showed relatively acceptable performance, with an MAE of 4.12 years. The application of neural networks creates new opportunities to obtain more accurate estimations of age in forensic research.

Morphology of maxilla in patients with palatally displaced canines.

OBJECTIVES: The aim of this study was to investigate the possible relationship between the morphology of maxilla and the palatally displaced canines (PDC). MATERIALS AND METHODS: In this cross-sectional study, there were 101 patients (45 males, 56 females) aged 12 to 16years, referred to Hamadan school of dentistry in 2014. They were divided into 3 groups: the bilateral PDC (PDCb) group (male=15, female=21), the unilateral PDC (PDCu) group (male=16, female=19), and the control group (male=14, female=16). Five morphology related variables including intermolar width, maxillary arch length, palatal vault depth, palatal intermolar area, and nasal width were measured using CBCT images with Dolphin Imaging software, version 11.5. Statistical analysis was performed with ANOVA and the Dunnett test using SPSS software, version 16.0. RESULTS: Only the palatal intermolar area and the palatal vault depth values were significantly less in the PDCu and the PDCb groups than those in the control group (the palatal intermolar area: 376.17, 381.93, and 423.75mm2, the palatal vault depth: 13.19, 13.42, and 14.59mm; respectively; P<0.05). For all the variables, there was no statistically significant difference between the PDCu and PDCb groups. CONCLUSION: Decreased palatal vault depth and palatal intermolar area may be correlated with greater chance of palatal displacement of canines. Future prospective studies in mixed dentition patients are needed as a predictive factor to find the probability of PDC.

Effect of Field of View on Detection of Condyle Bone Defects Using Cone Beam Computed Tomography.

In maxillofacial imaging, cone beam computed tomography (CBCT) is currently the modality of choice for assessment of bony structures of the temporomandibular joint (TMJ). Factors affecting the quality of CBCT images can change its diagnostic accuracy. This study aimed to assess the effect of field of view (FOV) and defect size on the accuracy of CBCT scans for detection of bone defects of the TMJs. This study was conducted on 12 sound TMJs of 6 human dry skulls. Erosions and osteophytes were artificially induced in 0.5, 1, and 1.5-mm sizes on the anterior-superior part of the condyle; CBCT scans were obtained with 6, 9, and 12-inch FOVs by NewTom 3G CBCT system. Two maxillofacial radiologists evaluated the presence/absence and type of defects on CBCT scans. The Cohen kappa was calculated to assess intra- and interobserver reliability. The Mann-Whitney U test was applied to compare the diagnostic accuracy of different FOVs.In comparison of 6- and 12-inch, 9- and 12-inch FOVs in detection of different sizes of erosive lesions, difference was significant (P <0.05), whereas difference between 6- and 9 inch just in 0.5-mm erosive lesion was significant (P = 0.04). In comparison of 6- and 12-inch FOVs in detection of different sizes of osteophyte lesion, difference was significant (P < 0.05), whereas between 6- and 9-inch FOVs statistically significant difference was not observed (P > 0.05). The highest and the lowest diagnostic accuracy of CBCT scans for condyle defects were obtained with 6-inch and 12-inch FOVs, respectively. Diagnostic accuracy of CBCT scans increased with an increase in size of bone defects.

Diagnosis of simulated condylar bone defects using panoramic radiography, spiral tomography and cone-beam computed tomography: A comparison study.

OBJECTIVES: Radiographic examination is one of the most important parts of the clinical assessment routine for temporomandibular disorders. The aim of this study was to compare the diagnostic accuracy of cone-beam computed tomography(CBCT) with panoramic radiography and spiral computed tomography for the detection of the simulated mandibular condyle bone lesions. STUDY DESIGN: The sample consisted of 10 TMJs from 5 dried human skulls. Simulated erosive and osteophytic lesions were created in 3 different sizes using round diamond bur and bone chips, respectively. Panoramic radiography, spiral tomography and cone-beam computed tomography were used in defect detection. Data were statistically analyzed with the Mann-Whitney test. The reliability and degrees of agreement between two observers were also determined by the mean of Cohen's Kappa analysis. RESULTS: CBCT had a statistically significant superiority than other studied techniques in detection of both erosive and osteophytic lesions with different sizes. There were significant differences between tomography and panoramic in correct detection of both erosive and osteophytic lesions with 1mm and 1.5 mm in size. However, there were no significant differences between Tomography and Panoramic in correct detection of both erosive and osteophytic lesions with 0.5 mm in size. CONCLUSIONS: CBCT images provide a greater diagnostic accuracy than spiral tomography and panoramic radiography in the detection of condylar bone erosions and osteophytes. Key words:Bone defect, Condyle, CBCT, Panoramic, radiography.

A comparative study of the conventional and digital intraoral radiography methods for root canal length measurement / Comparação entre Radiografia intraoral convencional e digital para medição de comprimento do canal radicular: estudo in vitro

Objective: Measurement of root canal length is one of the most important stages of endodentic treatment, and any error at this stage can lead to the failure. This study aimed to compare conventional and digital intraoral radiography in measurement of root canal length. Material and Methods: In this study, 35 single-canal maxillary teeth were collected. Access cavities were prepared. An endodontic number 10#K- file was introduced into the canal, until the tip was visible at the apical foramen and the actual canal length (gold standard) was determined. After acquisition conventional radiographs using E-Ektaspeed and F-Insight film (Eastman-Kodak Co. Rochester, NY, USA) and digital radiographs using Photostimulable Phosphor Plates(PSP) (Soredex, Helsinki, Finland) and Charge Coupled Devices (CCD)(RVG, Trophy,NY,USA). they were examined separately with a two-week interval by two oral and maxillofacial radiologists. The data were analyzed with ANOVA and Tukey’s tests using SPSS-19 software (SPSS Inc., Chicago, IL, USA). Result: No statistically significant difference was observed between different radiographies, and different observers (P > 0.05). Nevertheless, in comparison with the gold standard, in all cases, the F-speed conventional radiography and the digital CCD radiography showed the highest and the lowest accuracy, respectively. Also, the PSP and the E-speed conventional radiography were in the second and third order of accuracy, respectively. Conclusion: The use of digital radiography does not improve the accuracy of the root canal length measurement,but the digital technique has advantages,such as the reduced patient exposure, eliminating the time consuming processing stages, and producing fast images...

Objetivo: A medição do comprimento do canal radicular é uma das etapas mais importantes de tratamento endodôntico, e qualquer erro nesta fase pode levar ao fracasso. Este estudo teve como objetivo comparar a radiografia intra-oral convencional e digital na medida do comprimento do canal radicular.Material e Métodos: Neste estudo, 35 dentes superiores com canal único foram coletados. Cavidades de acesso foram preparadas. Uma lima endodôntica tipo K, número 10 foi introduzida no canal, até que a ponta era visível no forame apical e o comprimento do canal real (padrão ouro) foi determinada. Após a aquisição de radiografias convencionais, utilizando os filmes E-Ektaspeed e F- Insight (Eastman Kodak Co.,Rochester, NY, EUA) e radiografias digitais utilizando placas foto estimuláveis de fósforo (PSP) (Soredex, Helsinki, Finlândia) e dispositivos de acoplamento (CCD) (RVG, Troféu, NY, EUA), as mesmas foram examinadas separadamente com um intervalo de duas semanas, por dois radiologistas oral maxilofaciais. Os dados foram analisados pelos Testes de ANOVA e Tukey utilizando o software SPSS-19 (SPSS Inc., Chicago, IL, EUA). Resultados: Não houve diferença estatisticamente significativa entre as diferentes radiografias, e observadores diferentes (P > 0,05). No entanto, em comparação com o padrão-ouro, em todos os casos, a radiografia convencional e a radiografia digital CCD apresentaram o maior e a menor precisão, respectivamente. Além disso, a PSP e a radiografia convencional estavam na segunda e terceira ordem de precisão, respectivamente. Conclusão: O uso da radiografia digital não melhora a precisão da medição do comprimento de canal, mas a técnica digital tem vantagens, tais como a exposição do paciente reduzida, eliminando o demorado estágio de processamento, produzindo assim, imagens mais rápidas...

Diagnosis of simulated external root resorption using conventional intraoral film radiography, CCD, PSP, and CBCT: a comparison study.

BACKGROUND: Diagnosis of external root resorption (ERR) cavities may be challenging, especially when no clinical signs are seen. Therefore, the aim of this study was to compare the efficacy of conventional intraoral film radiography, charge-coupled device (CCD) detector, photostimulable phosphor plate (PSP) detector, and cone beam computed tomography (CBCT) for the detection of ERR. METHODS: The study sample comprised 54 maxillary first premolars. Cavities were created by using a low-speed handpiece with round diamond burs of 1 mm in diameter. Digital and conventional radiographs were taken from each tooth. Three observers examined all images for the presence of resorption cavities. Data were statistically analyzed with the χ(2) test. The reliability and degrees of agreement were also determined by the mean of Cohen's Kappa analysis. RESULTS: The differences between the imaging methods in correct detection of root resorption for all sizes were not significant. For locations of root resorption, significant differences were found between CBCT and other methods in the apical regions. CONCLUSIONS: CBCT was only useful for detection of cavities located in the apical one-third of the root, compared to other digital or conventional methods.

Effect of object location on the density measurement in cone-beam computed tomography versus multislice computed tomography.

BACKGROUND: Bone density measurement in a radiographic view is a valuable method for evaluating the density of bone quality before performing some dental procedures such as, dental implant placements. It seems that Cone-Beam Computed Tomography (CBCT) can be used as a diagnostic tool for evaluating the density of the bone, prior to any treatment, as the reported radiation dose in this method is minimal. The aim of this study is to investigate the effect of object location on the density measurement in CBCT versus Multislice computed tomography (CT). MATERIALS AND METHODS: In an experimental study, three samples with similar dimensions, but different compositions, different densities (Polyethylene, Polyamide, Polyvinyl Chloride), and three bone pieces of different parts of the mandibular bone were imaged in three different positions by CBCT and Multislice CT sets. The average density value was computed for each sample in each position. Then the data obtained from each CBCT was converted to a Hounsfield unit and evaluated using a single variable T analysis. A P value <0.05 was considered to be significant. RESULTS: The density in a Multislice CT is stable in the form of a Hounsfield Number, but this density is variable in the images acquired through CBCT, and the change in the position results in significant changes in the density. In this study, a statistically significant difference (P value = 0.000) has been observed for the position of the sample and its density in CBCT in comparison to Multislice CT. CONCLUSIONS: Density values in CBCT are not real because they are affected by the position of the object in the machine.