Comparison of Accuracy Between Pulp/Tooth Ratio and Tooth Coronal Index Methods for Dental Age Estimation Using Digital Panoramic Radiographs

Objective: To evaluate the reliability and the accuracy of Tooth Coronal Index (TCI) and Pulp/Tooth Ratio (PTR) methods in dental age estimation using digital panoramic radiography. Material and Methods: In this cross-sectional study, 237 dental panoramic images were collected. The two methods (TCI and PTR) were applied to all left mandibular first and second molars based on inclusion and exclusion criteria. In order to analyze the acquired data, statistical methods were used. The estimated ages derived by exclusive formula were compared to the chronological age, and the error ranges for each indicator were measured to determine their accuracy. Results: There were negative correlations between PTR in the first molar (r=-0.89) and in the second molar (r=-0.788), as well as TCI in the first molar (r=-0.587) and in the second molar (r=-0.242). In this study, we found that the Pulp/Tooth Ratio (PTR) accuracy rate for mandibular first and second molar teeth was 79.21% and 62.09 %, respectively, although the Tooth Coronal Index (TCI) value for these teeth was 34.45% and 5.85%. Conclusion: Pulp/Tooth Ratio and Tooth Coronal Index are potential age estimation indices. Although PTR was the more accurate one in our study. The results also demonstrated that indices related to the first molar tooth could be used to estimate age with greater accuracy and validity

Comparison of Accuracy Between Pulp/Tooth Ratio and Tooth Coronal Index Methods for Dental Age Estimation Using Digital Panoramic Radiographs

Objective: To evaluate the reliability and the accuracy of Tooth Coronal Index (TCI) and Pulp/Tooth Ratio (PTR) methods in dental age estimation using digital panoramic radiography. Material and Methods: In this cross-sectional study, 237 dental panoramic images were collected. The two methods (TCI and PTR) were applied to all left mandibular first and second molars based on inclusion and exclusion criteria. In order to analyze the acquired data, statistical methods were used. The estimated ages derived by exclusive formula were compared to the chronological age, and the error ranges for each indicator were measured to determine their accuracy. Results: There were negative correlations between PTR in the first molar (r=-0.89) and in the second molar (r=-0.788), as well as TCI in the first molar (r=-0.587) and in the second molar (r=-0.242). In this study, we found that the Pulp/Tooth Ratio (PTR) accuracy rate for mandibular first and second molar teeth was 79.21% and 62.09 %, respectively, although the Tooth Coronal Index (TCI) value for these teeth was 34.45% and 5.85%. Conclusion: Pulp/Tooth Ratio and Tooth Coronal Index are potential age estimation indices. Although PTR was the more accurate one in our study. The results also demonstrated that indices related to the first molar tooth could be used to estimate age with greater accuracy and validity

Age Estimation Based on Pulp–Tooth Volume Ratio of Anterior Teeth in Cone-Beam Computed Tomographic Images in a Selected Population: A Cross-Sectional Study

The present study aimed to investigate the correlation between chronological age and pulp–tooth volume ratio in anterior teeth using cone beam computed tomographic (CBCT) images and provide equations for age estimation based on pulp–tooth volume ratio. In this cross-sectional study, CBCT images of 312 anterior teeth of the maxilla and mandible were examineαd. The chronological age and the sex of the patients were recorded. Tooth volume and pulp volume of the anterior teeth were measured using Mimics software, and then tooth–pulp volume ratio was calculated. Statistical analysis of data was performed using chi-square test, independent T-test, Pearson’s correlation, and linear regression (α = 0.05). Finally, equations were made based on the results of the regression analysis for age estimation in general and for males and females. The age of the subjects ranged between 16 and 69 years (mean 40.6 ± 12.74). The pulp–tooth volume ratio of the maxillary teeth was generally higher than the mandibular teeth. A significant inverse relationship between age and pulp–tooth volume ratio was observed for all anterior teeth. (p < 0.05). The strongest correlation between age and pulp–tooth volume ratio was reported for mandibular central incisor (r = −0.58, p < 0.001) and the weakest was for mandibular lateral incisor (r = −0.36, p = 0.012). Age estimation was most accurate among females using the maxillary central incisors (p < 0.001) and among males using the mandibular central incisors and maxillary canines (p = 0.003). Pulp–tooth volume ratio of mandibular central incisors, maxillary lateral incisors, and maxillary canines in males and maxillary and mandibular central incisors, maxillary lateral incisors, and maxillary and mandibular canines in females can be used for age estimation

Effect of Filtration and Slice Thickness of Cone-Beam Computed Tomography Images on Occlusal Caries Detection: An Ex Vivo Study

Objectives: The aim of this study was to evaluate the diagnostic accuracy of different filtrations and slice thicknesses of cone-beam computed tomography (CBCT) in the detection of occlusal caries. Materials and Methods: One-hundred teeth were selected for this ex-vivo experimental study. The CBCT images of the teeth were evaluated and scored by two observers in panoramic and cross-sectional views using different slice thicknesses and filtrations. Paired t-test, repeated-measures analysis of variance (ANOVA), and the least significant difference (LSD) test were used to compare the data with the histological gold standard. Receiver operating characteristic (ROC) analysis was used to determine the diagnostic accuracy of each slice thickness and filtration (P<0.05). Results: The mean score of true caries detection in cross-sectional views was lower than that in panoramic views (P<0.05). Repeated-measures ANOVA showed a significant difference in the mean of true detections in different thicknesses of cross-sectional views, but this difference was significant only between 5 mm thickness and other thicknesses in panoramic views. On all the views, increasing the thickness decreased the accuracy of caries detection. Repeated-measures ANOVA showed a significant difference between different filtrations; on all the views, increasing the filtration increased the accuracy of caries detection. Conclusions: An increase of filtration of CBCT images increases the accuracy of occlusal caries detection; however, an increase in slice thickness results in a lower diagnostic accuracy

The accuracy of linear and angular measurements in the different regions of the jaw in cone-beam computed tomography views

Introduction: The use of cone-beam computed tomography (CBCT) has increased lately. The aim of this study was to evaluate the accuracy of linear and angular measurements by CBCT in the different areas of the jaws. Materials and Methods: In this study, the mesiodistal width and height as well as the angular measurements were ascertained in four different sites of the mandibular and maxillary jaws (anterior, canine, premolar, and molar regions). Each area was outlined by gutta-percha as opaque markers. The measurements were obtained by a digital caliper (as gold standard) and on CBCT views including “three-dimensional” and “panaroma” (section thickness of 5 and 10 mm). Data were analyzed by the one-way analysis of variance (ANOVA). Results: The means [standard deviation (SD)] of measurement accuracy of all groups were more than 90%. There was no significant difference between the means (SD) of measurement accuracy of all views (oneway ANOVA, P > 0.05). The means (SD) of measurement accuracy of all views in four regions of the jaws had no significant difference (one-way ANOVA, P > 0.05). Conclusion: This study showed that CBCT imaging has a high degree of measurement accuracy in all three horizontal, vertical, and angular measurements as well as the “panorama” (5- and 10-mm thicknesses) and “three-dimensional” views in all the areas of the jaws. Therefore, the use of CBCT in the linear and angular measurements of the dentomaxillofacial region can be recommended

Effect of Filtration and Thickness of Cross-Sections of Cone Beam Computed Tomography Images on Detection of Proximal Caries

Objectives: When a patient has cone beam computed tomography (CBCT) images based on the treatment plan, it is possible to use these images for evaluation of caries, and there is no need for new radiographs, according to the "as low as reasonably achievable" (ALARA) principle. The aim of this study was to determine the effect of filtration and thickness of CBCT cross-sections on detection of proximal caries. Materials and Methods: In this in-vitro study, 100 teeth were placed in the dental sockets of a dry skull, and were fixed in normal proximal contacts. CBCT images were taken and were evaluated by two observers on the panoramic view at 1-, 3- and 5-mm-thick cross-sections, with the use of filtrations 0, 1 and 2. Afterwards, the samples were sectioned and underwent a histological evaluation. McNemar’s test was used to compare the findings on CBCT images and histological evaluation. Receiver operating characteristic (ROC) curves and logistic regression were used to evaluate the diagnostic accuracy of different cross-sections. Results: The maximum AZ-value was achieved at 3-mm thickness/filtration 2. However, the differences between 1-mm thickness/filtration 2 and 1-mm thickness/filtration 1 were not significant (P=0.728 and 0.868, respectively). The minimum AZ-value was achieved at 5-mm thickness/filtration 0. Conclusions: Although CBCT is not sufficiently effective in detecting caries, the best cross-sections for detection of proximal caries were achieved at 3-mm thickness/filtration 2, 1-mm thickness/filtration 2 and 1-mm thickness/filtration 1

Knowledge, Attitudes and Performance of Dental Practitioners in Isfahan-Iran about Biologic Effects of Ionizing Radiation and Protection Against them in 2011

Introduction: Increasing use of dental radiography makes necessitates of increasing awareness and appropriate performance about ionizing radiation protection. The present study was done with the aim of evaluation of awareness, attitude and performance levels of dental practitioners in the city of Isfahan about ionizing radiation and protection against them.Materials & Methods: In this descriptive-analytic study a questionnaire including questions for evaluating of awareness, attitude and performance levels and demographic information was distributed among 184 dentists in the city of Isfahan. The data were analyzed by means of student t test and Pearson correlation coefficient in SPSS software (α=0.05). Results: In the present study 73.2% of dentists had weak awareness level 25.6% and 1.2% of dentists had moderate and good awareness levels respectively. Twentyfour and 76 percent had good and apathetic attitudes. Ten and 4.5 percent of dentists have been using lead apron and thyroidal necklace for their patients respectively. Experience and awareness had significant inverse correlation with eachother (P=0.004, r =-0.218).Conclusion: According to the results of the presents study, the awareness of dentists was weak and academic education as well as post-graduate education is necessary

The Effect of Changing Focal Trough in a Panoramic Device on the Accuracy of Distance Measurements

>Introduction: Magnification and distortion are the most important limitations of panoramic radiography. The aim of this study was to determine the effects of changing focal trough option of Planmeca SCARA 3 on the accuracy of linear distance measurements.Materials and Methods: In this in-vitro study, 28 pieces of gutta-percha were attached to the assumptive place of each lost root of an adult dry skull with average size and normal shape. The actual measurements were obtained by a digital caliper. The panoramic images of the skull were taken in six different sizes and shapes of focal trough. This procedure was repeated ten times with new gutta-percha. Paired t-test was used to compare the values of different actual and radiographic images of gutta-percha dimensions.Results: The mean difference [standard deviation (SD)] between actual measurement and panoramic radiography in the different groups was from 0.37 (1.1) to 0.58 (2.87) mm. The mean (SD) difference of linear measurements between real and radiographic images was 0.52 (0.43) mm in average size, V-shaped group, which was statistically and clinically significant (P = 0.00).Conclusion: Changing the focal trough option of Planmeca SCARA 3 has minimal effects on the accuracy of linear measurements in panoramic radiographs

Radiographic Evaluation of Bone Formation and Density Changes after Mandibular Third Molar Extraction: A 6 Month Follow up

Background: There is a controversy about exact time of bone healing. The aim of this study was evaluation of bone formation and change of density after mandibular third molar extraction. Methods: Radiographs were taken from 16 empty tooth sockets immediately after extraction of mandibular third molars and 2, 4 and 6 months later under similar condition. The radiographs were digitized and the density numbers of pixels were calculated. Then, socket and neighbor regions were compared using Photoshop software. Three expert observers evaluated and compared the radiographs by the longitudinal radiographic assessment (LRA) method. Paired t-test and McNemar test were used to analyze the data and investigate the inter-observer reliability, respectively. Results: Analysis of the quantitative digital subtraction radiography (QDSR) data indicated that the difference between the digital numbers of interest points and reference points has been decreased during the months 2, 4 and 6 but the difference between the month 4 and 6 was not significant. The alternative method indicated that the mean digital numbers in the socket within 0and 2 months period was less than 128 and within 4 and 6 months was more than 128. In evaluation of LRA method, lamina dura started to change gradually in month 2 and it might disappear completely after 6 months. Conclusion: Both QDSR and LRA methods can be used in evaluation of the rate of bone formation in the tooth socket but the former is more precise

Comparison of total phenolic and antioxidant activity of different Mentha spicata and M. longifolia accessions

This study investigated total phenolic and antioxidant activity of five Iranian mint accessions from two different species, Mentha spicata L. (Mzin1, Mzin3 and Mzin8) and M. longifolia L. (Mzin5 and Mzin6). The content of total phenolics (mg tannic acid equivalent per g dry weight of the sample) differed from 50.1 in Mzin3 to 67.2 in Mzin6. The highest percent radical scavenging activity was observed with Mzin6 at all concentrations studied (50, 100, 250, and 500 ppm). Peroxide value of sunflower oil containing Mzin5 and Mzin6 was the lowest among the mint accessions and almost equivalent to that of butylated hydroxytoluene at 200 ppm concentration. In overall, M. longifolia was superior to M. spicata, as determined by two model systems, indicating its potential use as a natural source of dietary antioxidant