Direct and Indirect Forensic Age Estimation Methods for Deciduous Teeth

Background & objectives:Estimation of haemoglobin is the most widely used method to assess anaemia. Although direct cyanmethaemoglobin method is the recommended method for estimation of haemoglobin, but it may not be feasible under field conditions. Hence, the present study was undertaken to compare indirect cyanmethaemoglobin method against the conventional direct method for haemoglobin estimation.Methods:Haemoglobin levels were estimated for 888 adolescent girls aged 11-18 yr residing in an urban slum in Delhi by both direct and indirect cyanmethaemoglobin methods, and the results were compared.Results:The mean haemoglobin levels for 888 whole blood samples estimated by direct and indirect cyanmethaemoglobin method were 116.1 ± 12.7 and 110.5 ± 12.5 g/l, respectively, with a mean difference of 5.67 g/l (95% confidence interval: 5.45 to 5.90, P<0.001); which is equivalent to 0.567 g%. The prevalence of anaemia was reported as 59.6 and 78.2 per cent by direct and indirect methods, respectively. Sensitivity and specificity of indirect cyanmethaemoglobin method were 99.2 and 56.4 per cent, respectively. Using regression analysis, prediction equation was developed for indirect haemoglobin values.Interpretation & conclusions:The present findings revealed that indirect cyanmethaemoglobin method overestimated the prevalence of anaemia as compared to the direct method. However, if a correction factor is applied, indirect method could be successfully used for estimating true haemoglobin level. More studies should be undertaken to establish agreement and correction factor between direct and indirect cyanmethaemoglobin methods.

Introduction: The most reliable indicator for anaemia diagnosis at the population level is haemoglobin (Hb) estimation. The direct cyanmethaemoglobin method is considered the gold standard method for haemoglobin estimation. However, for resource constraint areas like primary health care (PHC) level, either blood samples are transported on filter paper for Hb testing (indirect cyanmethaemoglobin method) in laboratory or point of care testing is commonly used. Therefore, a comparative analysis of haemoglobin estimation of direct with indirect cyanmethaemoglobin method and also with TrueHb (Wrig Nanosystems Pvt. Ltd.) haemometer was done to strengthen anaemia diagnosis at the PHC level. Materials and Methods: This was a cross-sectional study. A total of 90 participants above 9 years of age, who visited the outpatient department (OPD) of health centre, Kheri and gave consent were included. Comparative analysis was done between Hb concentration assessed by indirect cyanmethaemoglobin method and TrueHb haemometer device against the gold standard method. Results: The mean Hb value estimated by direct method, TrueHb haemometer and indirect methods (filter paper A, B and C) was 11.42 ± 1.59 g/dl, 11.52 ± 1.54 g/dl, 10.66 ± 1.52 g/dl, 9.84 ± 1.50 g/dl and 10.19 ± 1.62 g/dl, respectively. There was no significant difference found between the mean Hb concentration estimated by the direct method and the TrueHb haemometer device. However, there was a significant difference in mean Hb values between the direct method and the indirect method. Therefore, regression analysis was done to estimate the correction factor for the indirect method. Conclusion: TrueHb metre device gave promising results in comparison to the gold standard method and can be used if resource permits in PHC centres. Indirect methods of haemoglobin estimation can be an alternative in resource-constraint settings, specifically for surveys. However, further studies are required for the validation of the indirect method.

Objective To compare the reproducibility and reliability of facial soft tissue landmarks using a direct and an indirect placement methods in facial three-dimensional (3D) soft tissue assessment.Methods 3D coordinates of 37 soft tissue landmarks were obtained respectively in 35 normal healthy volunteers from 3D optical capture system and Materialise's interactive medical image control system (Mimics).Landmarks were affixed on the cutaneous surface (direct method) and marked on the 3D reconstructed craniofacial model (indirect method).Intra-class correlation coefficients (ICCs) and paired t-tests were used to compare the reliability and reproducibility of facial landmarks between two placement methods.Results For the direct placement method,86.5 ％ landmarks had an ICC higher than 0.75.For the indirect placement method,75.7％ landmarks had an ICC higher than 0.75.The inter-observer variability using the direct placement method was (1.259±0.566) mm,which was significantly smaller (P＜0.05) than (1.420±0.638) mm obtained by the indirect placement method.Conclusions Compared with indirect method,direct method has higher reliability and reproducibility in evaluating facial soft tissue. Key words: Computed tomography; Cephalometrics; Optical capture technology

Analysis of direct and indirect quantification methods of CO2 fixation via microalgae cultivation in photobioreactors: A critical review

The as-cast properties of components with a columnar grain structure are very different from those with an equiaxed one. Under certain solidification conditions, zones of both structures can occur in an alloy casting; the boundary between the zones is the columnar-to-equiaxed transition (CET). A front-tracking model of dendritic solidification has been developed, which can predict the nucleation and growth of solid in undercooled liquid during a casting process. The growth process is described by dendrite tip kinetics, and is fully coupled to a fixed-grid control volume model of heat transfer during solidification. Using the front-tracking model, two methods for predicting the likelihood of an equiaxed zone forming ahead of a columnar front have been formulated, namely, an indirect method and a direct method. The indirect method is based on modelling the growth of the columnar front in the absence of equiaxed nucleation. The bulk liquid undercooling is monitored and an equiaxed indicator is calculated at each time step based on the extent of such undercooling at that time. The equiaxed indicator is a measure of the relative likelihood of an equiaxed zone forming. In the direct method nucleation and growth of individual equiaxed grains is treated ahead of the advancing columnar front. In this case, if impingement of neighbouring fronts is treated, the simulation to complete solidification will yield the macrostructure and the CET. In this paper, details of both methods of equiaxed prediction are presented. Results from the indirect method are compared to experimental results found in literature and agreement is found.

For many medical questions, X-ray imaging belongs to the gold standard for diagnosis, treatment planning, treatment guidance, and surgery assessment. To improve the reading performance, standardized image rotation is an important step. We propose a new algorithm to estimate the correct image rotation. For many body regions, one line can be defined that is aligned with the upright orientation of the X-ray image. This line can be, for example, the shaft axis of a long bone or the axis of the spine. In this paper, we propose a strategy to automatically align X-ray images with their standard orientation. In a first step, the heatmap of this line is determined using the segmentation network D-LinkNet. The rotation direction, up to a top-down flip, is obtained by computing the orientation of the main axis of this heatmap. For the orientation computation, we compare PCA and Hu moments. While the PCA requires to threshold the heatmap, Hu moments can be used directly on the output values of the network, preserving the (un)certainty of the segmentation. We compare these two methods with a ResNet-18 for the direct estimation of the image rotation on 220 X-ray images from the MURA dataset showing the wrist in the AP view. With the heatmap-based approach followed by Hu moments analysis, the median absolute error for the angle estimation can be reduced to 0.7° compared to 1.7° by a direct estimation method. PCA suffers from noisy heatmaps for images of bad quality degrading the overall performance of this approach.

Methods for age estimation in children involve measurements of: (1) the projections of open apices and tooth heights (T), (2) the total area of the carpal bones and the epiphyses of the ulna and radius (HW), and (3) a combination of these parameters (THW). This study aimed to compare the accuracy of the original formulae for T, HW, and THW in Black South African (BSA) and White South African (WSA) samples of children and adolescents. The sample comprised 556 subjects, 164 BSA (71 males and 93 females) and 392 WSA (171 males and 221 females) aged 6 to 16 years. The main sample comprised 556 subjects and was divided into two parts. The first part was used to develop new formulae specific to the South African population, while the second part, consisting of 183 subjects and referred to as the test sample, was used to evaluate the accuracy of these formulae and to quantify their uncertainty when applied to real cases. Adjusted R2 and standard errors of the estimate (SEEs) were calculated for each regression model. The mean absolute difference or error (MAE) between estimated and chronological age and the percentage of individuals within specific age ranges of ± 0.25, ± 0.5, ± 1, and ± 2 years of chronological age was used to compare the accuracy of formulae. Teeth showed the most significant underestimation in the training sample, -0.49 years in males and - 0.29 years in females, as much as -0.70 years in WSA males, while BSA males were overestimated by + 0.03 years. Combining teeth and hand-wrist, the new formula showed the best performance in age estimation compared to only teeth or hand-wrist, except in WSA males (-0.51 years). New South African-specific formula improved accuracy, especially in males, suggesting their suitability alongside the original Cameriere et al. methods for precise age estimation. The original regression formulae by Cameriere et al., along with the newly developed formulaespecific to South African populations, shows promise for age estimation, considering potential estimation errors and the accuracy rates demonstrated in this study.

Forest site classification has long been a problem for managers of Turkish forests. Forest management decisions and land use planning involving afforestation activities and silvicultural prescriptions are based on sound site information to formulate appropriate actions on the ground. In Turkey, two methods of forest site productivity are used; direct and indirect method. Indirect methods are usually reserved for practical applications as they are relatively simple, yet provide less accurate estimation of the real productivity. In this study direct, indirect and remote sensing (RS) methods were used to distinguish and map forest sites of Karanlikdere Forest District in Gumushane, Turkey. One hundred and twenty-two sample plots were established with 300 m × 300 m grids in summer of 2003. In each sample plot, soil samples and the classical timber inventory measurements were taken. According to direct method, water-air economy method is preferred due to a water deficiency in the study area. Four different forest site classes; very dry, dry, moderate fresh and fresh were determined and mapped with geographic information system (GIS). In indirect method, the guiding curve was used to generate anamorphic site indexes (SI) of three classes; good (SI = I and II), medium (SI = III) and poor (SI = IV and V). Furthermore, forest sites were estimated with Landsat 7 ETM (2000) data using supervised classification with a 0.843 kappa statistic value and 88% accuracy assessments. Some important differences between the methods were discovered. The indirect method indicate that site indices I and II are 298.5 ha, III 254.3 ha and IV and V 347.7 ha. In contrast, direct method related to very dry site of 107.7 ha, dry site of 484.6 ha, moderate fresh site of 304.7 ha and fresh site of 246.3 ha. Satellite image indicate that very dry site covers 291.2 ha, dry site 239.2 ha, moderate fresh site 287.4 and fresh site 325.5 ha. Approximately 242.8 ha area (open and degraded areas) were not determined by indirect method but were captured with RS method. The statistical analyses (ANOVA) showed no statistically significant (F = 0.720, p = 0.543) relationship between indirect method and direct method-RS method indicating clearly that indirect method is not an adequate measurement of forest site productivity. Forest sites, particularly in open and degraded areas should be determined with direct method.

Aforestation activities, silvicultural prescription, forest management decisions and land use planning are based on site information to develop appropriate actions for implementation. Forest site classification has been one of the major problems of Turkish forestry for long time. Both direct and indirect methods can be used to determine forest site productivity. Indirect methods are usually reserved for practical applications as they are relatively simple, yet provide less accurate site estimation. However, direct method is highly time-demanding, expensive and hard to conduct, necessitating the use of information technologies such as Geographic Information Systems (GIS) and Remote Sensing (RS). This study, first of all, generated a forest site map using both direct and indirect methods based on ground measurements in 567.2 ha sample area. Then, supervised classification was conducted on Landsat 7 ETM image using forest site map generated from direct method as ground measurements to generate site map. The classification resulted in moist site of 262.5 ha, very moist site of 122.5 ha and highly moist site of 191.2 ha in direct method; sites I-II cover 38.9 ha, III 289.6 ha, IV-V 143.5 ha and treeless-degraded areas of 104.2 ha in indirect method; moist site of 203.5 ha, very moist site of 232.1 ha and highly moist site of 140.6 ha in remote sensing method. However, 104.2 ha treeless and degraded areas were not determined by indirect method, yet by the other methods. Secondly, forest site map for the whole area (5,980.8 ha) was generated based on the site map generated by the direct method for sampled area. The Landsat 7 ETM image was classified based on the forest site map of sample area. The site index (SI) map for the whole area was generated using conventional inventory measurements. The classification resulted in sites I-II cover 134.1 ha, III 1,643.6 ha, IV-V 1,396.5 ha, treeless-degraded areas of 1,097.3 ha and settlement-agriculture areas of 1,709.3 ha in indirect method; moist site of 1,674.3 ha, very moist site of 853.6 ha, highly moist site of 1,729.6 ha and settlement-agriculture areas 1,723.3 ha in remote sensing method. Again the treeless- degraded areas of 1,097.3 ha were not determined by indirect method but by remote sensing method.

Effectiveness of three age estimation methods based on dental and skeletal development in a sample of young Brazilians

ObjectiveThis experiment was conducted as a 3×2×2 factorial design to examine the effects of particle size (mean particle size of 331, 640, or 862 μm), evaluation method (direct vs indirect method) and adaptation duration (7 or 26 days) on the energy content and the apparent total tract digestibility (ATTD) of various chemical components in wheat when fed to finishing pigs.MethodsForty-two barrows (Duroc×Landrace×Yorkshire) with an initial body weight of 63.0±0.8 kg were individually placed in metabolic cages and randomly allotted to 1 of 7 diets with 6 pigs fed each diet. For the indirect method, the pigs were fed either a corn-soybean meal based basal diet or diets in which 38.94% of the basal diet was substituted by wheat of the different particle sizes. In the direct method, the diets contained 97.34% wheat with the different particle sizes. For both the direct and indirect methods, the pigs were adapted to their diets for either 7 or 26 days.ResultsA reduction in particle size linearly increased the digestible energy (DE) and metabolizable energy (ME) contents as well as the ATTD of gross energy, crude protein, organic matter, ether extract (EE) and acid detergent fiber (ADF) (p<0.05), and had a trend to increase the ATTD of dry matter of wheat (p = 0.084). The DE, ME contents, and ATTD of gross energy, crude protein, dry matter and organic matter were higher (p<0.05) when determined by the direct method, but the ATTD of ADF, EE, and neutral detergent fiber were higher when determined by the indirect method (p<0.05). Prolongation of the adaption duration decreased the ATTD of neutral detergent fiber (p<0.05) and had a trend to increase the ATTD of EE (p = 0.061). There were no interactions between particle size and the duration of the adaptation duration. The ATTD of EE in wheat was influenced by a trend of interaction between method and adaptation duration (p = 0.074). The ATTD of ADF and EE in wheat was influenced by an interaction between evaluation method and wheat particle size such that there were linear equations (p<0.01) about ATTD of ADF and EE when determined by the direct method but quadratic equations (p = 0.073 and p = 0.088, respectively) about ATTD of ADF and EE when determined by the indirect method.ConclusionDecreasing particle size can improve the DE and ME contents of wheat; both of the direct and indirect methods of evaluation are suitable for evaluating the DE and ME contents of wheat with different particle sizes; and an adaptation duration of 7 d is sufficient to evaluate DE and ME contents of wheat in finishing pigs.

Affixing markers on the face in vivo with an optical surface imaging system and placing landmarks on a computed tomographic reconstructive facial model represent two helpful approaches prevailing in three-dimensional cephalometric analysis of facial aesthetics. In this study, the authors determine the suitability of these methods for soft-tissue evaluation along with the reproducibility and reliability of landmark placement. Thirty-seven soft-tissue landmarks were investigated in 35 normal healthy volunteers who underwent cephalometric analysis by direct and indirect placement methods. Two operators performed the analysis twice for each method at a 1-week interval. Landmark positions were measured on the three-dimensional coordinates, and data were standardized and converted into landmark placement errors for the estimation, by two-way random intraclass correlation coefficients. Using the direct method, 86.5 percent of the landmarks had a higher intraclass correlation coefficient than 0.75, and 67.6 percent were higher than 0.90. The authors found that 75.7 percent were higher than 0.75 and 43.2 percent were higher than 0.90 with the indirect method. Both methods showed good reliability in identifying midline-related structures, although the correlations of markers surrounding eyelashes and lips were better using the direct method. The direct method had a significantly smaller landmark placement error and better reproducibility than that identified indirectly (p<0.05). When evaluating well-defined contours and the natural texture of the face, the direct placement method shows better accuracy than the indirect method. The three-dimensional evaluation emphasizes the eye, lip, and some structures more laterally, therefore providing comprehensive analysis for clinical diagnosis. Diagnostic, II.

Hepatitis C virus has infected over 71 million people worldwide, and it is the main cause of cirrhosis in the western world. Currently, the treatment involves direct-acting antiviral agents (DAAs) and its main goal is to achieve sustained virologic response (SVR). The aim of this study was to evaluate the impact of SVR using DAAs in the improvement of liver fibrosis using scores evaluation by indirect method, liver function, and inflammation indirect biomarkers. Patients with cirrhosis with SVR after treatment (n = 104) were evaluated using liver function scores, indirect fibrosis methods, alpha-fetoprotein, and ferritin at t-base and t-SVR. Statistically significant positive results in all parameters were observed: 54 patients were classified as 5 in the CP score in t-base, and 77 in t-SVR; a significant decrease was observed in MELD score, alpha-fetoprotein, ferritin, APRI, FIB-4 and liver stiffness in liver elastography. We did not observe difference in the liver function scores between regressors and non-regressors of liver stiffness, as well as in indirect inflammation biomarkers. The measurements of fibrosis using the indirect methods have significantly decreased in patients with cirrhosis treated who achieved SVR associated with decreased indirect inflammation biomarkers and improved liver function scores.

Determination of nitrofurantoin in pharmaceutical preparations using flow injection-spectrophotometry

To develop and validate formulas for age and sex estimation based on the pulp cavity volume of teeth using cone beam CT. The sample was composed of 116 cone beam CT scans from Brazilian individuals of both sexes, ranging in age from 13 to 70 years. A total of 232 teeth (upper central incisors and canines) were evaluated. Two calibrated examiners determined pulp cavity volumes using the ITK-SNAP software. Pearson's correlation test was used to assess the correlation between chronological age and pulp volume. Linear and logistic regression models were developed for age and sex estimation, respectively, and were validated in another sample of 72 teeth. Pearson's correlation coefficients between age and pulp volume were negative and significant (p < 0.0001) for both teeth (r = -0.8782 for central incisors and r = -0.8738 for canines). The age estimation formulas showed good determination coefficients (adjusted R² = 0.7614 to 0.8367). For sex estimation, when the age was known, the coefficients were also good (adjusted R² = 0.649 to 0.812). However, when the age was unknown, the coefficients of the sex estimation formulas were low (adjusted R² = 0.047 to 0.393). Validation showed high accuracy of age estimation in individuals older than 35 years, as well as high accuracy of sex estimation when the age was known. Our formulas provided excellent results and can be applied to the Brazilian population. The best results were observed for age estimation in females and for sex estimation when the age was known.