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1.
Age estimation by third molar mineralization has been developed for a period of time. Recent studies showed that impaction status has an influence on the rate of the third molar mineralization in Europids and male Black African populations. In this regard, the present study was conducted to determine whether the impaction status could delay the chronological process of third molar mineralization in northwestern Chinese population too. A total of 3,512 digital orthopantomograms of 1,255 male and 2,257 female northwestern Chinese subjects aged from 11 to 26 years were assessed based on the formation stages described by Demirjian et al. with two modifications. Mineralization stage and impaction status were determined for all third molars. Statistical measures were calculated at stages C–H in the male and female gender for both impacted and non-impacted third molars. It was ascertained that the mean ages with impacted third molars at stages C–H were 0.02–1.42 years higher in males and 0.04–1.52 years higher in females than those with non-impacted third molars, but statistical differences were only found at stages C, D, and E in males and stages D and E in females. The probabilities of being under 14, 16, or 18 years of age with non-impacted third molars were all higher than those with impacted third molars. The results prove that impacted third molars show significant slower mineralization than non-impacted ones at stages D and E in both males and females of northwestern Chinese population. It is recommended to consider the influence of impaction on the rate of third molar mineralization for dental age estimation.  相似文献   

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3.
From a forensic perspective, attaining the ages of 12, 15 and 18 is particularly important with respect to the Turkish Penal Code (TPC). The aim of this study is to obtain data regarding third molar development in the Turkish population for age estimation and to investigate the contribution of third molar development to age estimation in relation to the TPC. The study was applied with panoramic radiography on 379 male and 405 female subjects. The mineralization status of the third molars were evaluated on the basis of Demirjian’s classification system. It was determined that ‘0’ and ‘A’ stages for under-12 years of age, ‘B’ and ‘C’ stages for under-15, ‘D’ stage for under-18, ‘E’ and ‘F’ stages for over-12, ‘G’ stage for over-15 and ‘H’ stage for over-18 were specific stages for both genders. Specific stages that are detected according to the developmental stages of the third molars were not found to be adequately precise for distinguishing legal age thresholds. However, this study shows that matured third molars (reaching H stage) are indicative of an individual’s being over 18 years of age for both genders in Turkey.  相似文献   

4.
Radiographic evaluation of mineralization and eruption stages of third molars using dental panoramic radiographies can be an efficient tool for chronological age estimation in both forensic sciences and legal medicine. The third molar tooth is utilized for dental age estimation about the age span of 15–23?years because it represents the only tooth still in development. The aim of this study is to obtain and analyze data regarding third molar development and eruption in Turkish population for dental age estimation. A total of 744 dental panoramic radiographies of 394 female and 350 male subjects aged between 8 and 22?years were examined. Third molar development was determined according to the Nolla classification system, and eruption was assessed relative to the alveolar bone level. Mandibular and maxillary third molars were generally found at similar stages of development on both sides. Nolla stage 6 (completed crown calcification) was reached at around the age of 15 in both maxillary and mandibular third molars in both sexes. Alveolar emergence was at around the age of 16 in males and around age of 17 in females. Although third molars’ eruption shows greater variability than development of third molars, data which were obtained from this study about eruption of these teeth can be supportive to development data for age estimation.  相似文献   

5.
In Germany, a sharp increase in forensic age estimations of living individuals has been observed in recent years. With regard to the relevant age group, radiologic assessment of the mineralization stage of the third molars is of particular importance. Still, the influence of ethnicity on the pace of mineralization has been insufficiently analyzed. A total of 1615 orthopantomograms of 929 female and 686 male Japanese subjects aged between 12 and 30 years was examined. The mineralization stages of third molars were evaluated on the basis of Demirjian's stages modified in accordance with Mincer's model. For the individual mineralization stages, the study presents the means and standard deviations for the genders separately. No statistically significant differences in the chronology of third molar mineralization between maxilla and mandible and between sides were observed. A comparison between genders largely did not render significant differences either. Apart from forensic age determination in living subjects, the presented reference data can also be used for age estimations of unidentified corpses and skeletons.  相似文献   

6.
In Germany a sharp increase in forensic age estimations of living individuals has been observed in recent years. With regard to the relevant age group, radiological assessment of the mineralization stage of the third molars is of particular importance. However, the influence of ethnicity on the rate of mineralization has been insufficiently analyzed. A total of 1,437 orthopantomograms from 860 female and 577 male Germans aged between 12 and 26 years were examined. The mineralization stage of the third molars was evaluated based on the classification of stages proposed by Demirjian. For the individual mineralization stages, the study presents the means and standard deviations for the genders separately. Statistically significant differences in the chronology of third molar mineralization between maxilla and mandible or between the two sides could not be observed. A comparison between genders did not reveal significant differences either.  相似文献   

7.
The number of criminal cases involving Turkish juveniles has increased in recent years. To date, there is no method for chronological age estimation according to third-molar mineralization in Western Turkish children and adolescents. The aim of this study was to investigate the mandibular third molar development according to the eight stages (A–H) of the Demirjian method and to compare third-molar development according to gender and age with previous data. The digital orthopantomograms of 1120 white Turkish children (406 boys, mean age 15.17 ± 3.80 years, and 714 girls, mean age 16.83 ± 3.59 years) aged 7 to 22 years, from the Western Anatolia region were retrospectively reviewed. The Turkish population reached stage H at a mean age of 20 years in both genders. Dental mineralization in Western Turkish children was delayed at stages D–G but advanced at stage H compared with that in Turkish children in other regions. Third molar root development can reliably estimate the mean age and age range for a juvenile of unknown chronological age, especially compared with the standard deviation obtained using other techniques for calculating the skeletal age of the hand-wrist or long bones.  相似文献   

8.
The accuracy of forensic age estimation based on the chronology of second (M2) and third molar (M3) development was investigated using 2,087 orthopantomograms of Korean men and women aged between 3 and 23 years. The developmental stages of M2s and M3s in these subjects were classified using the criteria of Demirjian. Inter-observer reliability and statistical data on each stage of mineralization of M2s and M3s were evaluated. The left–right symmetries of the maturation degrees in the M2s and M3s were observed in both sexes, between which no arch differences were found, but statistically significant sex-specific differences were observed in some stages of M2 and M3 development. In multiple regression analysis, a strong positive relationship was observed between age and mineralization of M2s and M3s. The regression formulas for estimating the age of Koreans were presented based on sex and combination of teeth. These results suggest that the developments of second and third molars can be considered as valuable age indicators in Korean adolescents and young adults.  相似文献   

9.
One major criterion for dental age estimation is the evaluation of third molar mineralization. There are various methods for evaluating tooth mineralization based on classification by stages. The aim of the present work is to assess the validity of the common classification systems. To this end, we analyzed 420 conventional orthopantomograms of German females aged 12–25 years old. The mineralization status of tooth 38 was determined using the stages defined by Gleiser and Hunt, Demirjian et al., Gustafson and Koch, Harris and Nortje and Kullman et al., respectively. Of the methods tested, the most accurate results were obtained with Demirjian et al.s classification system, which performed best not only for observer agreement but also for the correlation between estimated and true age. It is argued that this is due to the fact that Demirjian et al.s classification is based on a sufficient number of stages which are defined independently of speculative estimations of length. This leads to the conclusion that the method devised by Demirjian et al. should be used for evaluating the mineralization of third molars for purposes of forensic age determination.  相似文献   

10.
The purpose of the study was to estimate the chronology of third molar mineralization in Han population of southwestern China and find its unique characteristics so that it would provide a reference in several legal cases like forensic age estimation. The study used Demirjian's staging method to study 2192 orthopantomograms of 984 male and 1208 female subjects aged between 8 and 25 years. The statistical data was analyzed by Student's t test and ANOVA.The conclusions of the study are: (1) The chronological mineralization age of third molars of Han population in Southwestern China is similar to the Turkish and the Japanese, was earlier than the Austrian and Han of South China, but later than the Spanish. (2) The mineralization timing of the third molars between two sides in maxilla or mandible has no significant differences in the same gender group. (3) There is no significant difference in mineralization of third molars between male and female, except for tooth 48 in Demirjian's stage E. (4) The mineralization of third molar in maxilla is earlier than mandible.  相似文献   

11.
In Germany, a sharp increase in forensic age estimations of living persons has been observed in recent years. German law defines four legally relevant age limits: 14, 16, 18 and 21 years. In these age groups, radiographic assessment of the mineralization status of third molars is of particular importance. So far, the influence of ethnicity on the mineralization rate has been insufficiently analyzed. A total of 3031 orthopantomograms of 1597 Japanese and 1434 Germans aged between 12 and 26 years were examined. The mineralization status of third molars was evaluated on the basis of the classification proposed by Demirjian. For the individual mineralization stages, the study presents the mean values and standard deviations (SD) separately for both populations and sexes. The majority of probands from both the Japanese and the German population achieved the C stage and the late G and H stages of third molar development at similar ages. Significant differences between Japanese and Germans were observed, however, with regard to the D, E and F stages defined by Demirjian. Japanese men and women achieved the D, E and F stages approximately 2-3 years later than German men and women. In addition to forensic age determination in living persons, the presented reference data can also be used for age estimations of unidentified deceased persons and skeletons.  相似文献   

12.
In order to study the chronology of age of third molar mineralization of Han in southern China, Demirjian staging method was used to determine the stage of four third molars (18, 28, 38, 48) mineralization in 3,100 Han in southern China aged 4.1–26.9 years based on radiological evidence from digital orthopantomograms. The mean age of the 3,100 patients was 15.96 ± 4.73 years, including 1,200 male (mean age, 15.32 ± 4.62) and 1,900 female (mean age, 16.35 ± 4.76). Results show that there was no significant difference in mineralization between 18 and 28 and 38 and 48 of male or female. However, significant difference was observed between 28 and 38 of female at stage C; 28 was 0.25 years earlier than 38. In male, at stage G, 38 was 0.61 years earlier than 28, and 48 was 0.62 years earlier than 18. At stages D, E, F, G, and H, male 48 was 0.34, 0.66, 0.72, 1.34, and 0.76 years earlier than that of female, respectively. At stages A, D, E, F, G, and H, male 38 was 0.73, 0.26, 0.56, 0.91, 1.29, and 0.70 years earlier than that of female, respectively. At stages B, E, F, G, and H, the mineralization mean age of male 18 was 0.54, 0.50, 0.76, 0.92, and 0.58 years earlier than that of female, respectively. At stages E, F, G, and H, the mineralization mean age of male 28 was 0.51, 0.76, 0.92, and 0.49 years earlier than that of female, respectively. After reviewing the literature, the chronological mineralization age of 48, at stages D to G, of Han in southern China was 1 to 4.6 years earlier than that of Japanese and 1 to 3 years earlier than that of German. The mean age at stage H of 48 of Han in southern China was similar to Turkish, Black African, Japanese, and German, but was later than Spanish. Finally, the conclusions are: (1) in the same gender group of Han in southern China, the mineralization ages between two sides in upper or lower jaw are very similar, and (2) the chronology mean age and complete time of third molar mineralization of male were earlier than that of female.  相似文献   

13.

Age estimation using developing third molar teeth is considered an important and accurate technique for both clinical and forensic practices. The aims of this study were to establish population-specific reference data, to develop age prediction models using mandibular third molar development, to test the accuracy of the resulting models, and to find the probability of persons being at the age thresholds of legal relevance in a Thai population. A total of 1867 digital panoramic radiographs of Thai individuals aged between 8 and 23 years was selected to assess dental age. The mandibular third molar development was divided into nine stages. The stages were evaluated and each stage was transformed into a development score. Quadratic regression was employed to develop age prediction models. Our results show that males reached mandibular third molar root formation stages earlier than females. The models revealed a high correlation coefficient for both left and right mandibular third molar teeth in both sexes (R = 0.945 and 0.944 in males, R = 0.922 and 0.923 in females, respectively). Furthermore, the accuracy of the resulting models was tested in randomly selected 374 cases and showed low error values between the predicted dental age and the chronological age for both left and right mandibular third molar teeth in both sexes (−0.13 and −0.17 years in males, 0.01 and 0.03 years in females, respectively). In Thai samples, when the mandibular third molar teeth reached stage H, the probability of the person being over 18 years was 100 % in both sexes.

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14.
Dental age estimation methods based on the radiologically detected third molar developmental stages are implemented in forensic age assessments to discriminate between juveniles and adults considering the judgment of young unaccompanied asylum seekers. Accurate and unbiased age estimates combined with appropriate quantified uncertainties are the required properties for accurate forensic reporting. In this study, a subset of 910 individuals uniformly distributed in age between 16 and 22 years was selected from an existing dataset collected by Gunst et al. containing 2,513 panoramic radiographs with known third molar developmental stages of Belgian Caucasian men and women. This subset was randomly split in a training set to develop a classical regression analysis and a Bayesian model for the multivariate distribution of the third molar developmental stages conditional on age and in a test set to assess the performance of both models. The aim of this study was to verify if the Bayesian approach differentiates the age of maturity more precisely and removes the bias, which disadvantages the systematically overestimated young individuals. The Bayesian model offers the discrimination of subjects being older than 18 years more appropriate and produces more meaningful prediction intervals but does not strongly outperform the classical approaches.  相似文献   

15.
A sharp increase in forensic age estimation of living persons has been observed in recent years. However, ethnic populations residing in different countries have been insufficiently analyzed. The aim of this study was to achieve a referral database and regression equations for dental age estimation of unaccompanied minors of Iran nationality. A total of 1200 orthopantomograms were collected from original Iran and equally divided in age categories between 10 and 27 years. On the radiographs, the developmental stage of the third molars was scored applying a Demirjian et al. scoring technique. Inter- and intra-observer reliabilities were tested using kappa statistics. Correlation between the scores of all four wisdom maxillary and mandibular third molars teeth and left/right symmetry were evaluated with spearman correlation coefficient. Student’s t-test on asymmetry was performed and regression formulas were calculated. The present database was the first to assemble third molar developmental scores on radiographs of Iran individuals and provided more appropriate dental age estimation of unaccompanied Iran minors. To enhance the accuracy of forensic age estimates based on third molars mineralization, the use of population-specific standards is recommended.  相似文献   

16.

In forensic medicine and many other fields, age estimation by the use of teeth is of great importance for the purpose of individual identification. In the past, however, age estimation based on the second molar mineralization was scarcely performed. In this study, a total of 1657 panoramic radiographs taken from 834 males and 823 females of northern Chinese origin in the age bracket 5 to 25 years were assessed. The mineralization status of the second molars was determined using the classification described by Demirjian et al. Results showed that the left and right, as well as maxillary and mandibular second molars were generally at similar stages of mineralization. The maxillary left second molars (27) at stage D, mandibular left second molars (37) at stages C, D, F, and G, and mandibular right second molars (47) at stages D, F, and G showed a significantly lower average age in female subjects than in male subjects. In males, fully developed second molars first appeared with 12 years of age; in females, stage H occurred with 11 years at the earliest. One male individual and one female individual with second molars showing stage G were 23 years old. It was concluded that second molars showing stage H do not exclude an age under 14 years and that second molars showing stage G do not exclude an age above 18 years.

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17.
Third molars are of special interest concerning legally relevant age groups in forensic age estimation by means of examination of dental mineralization. This study investigated the influence of wisdom tooth impaction on the mineralization rate. A total of 1,198 orthopantomograms from 629 female and 569 male German individuals (age range 15-40 years) were examined. After assessing the dental mineralization of the third molar in cases with stage H according to Demirjian, wisdom tooth impaction was determined. Females with complete wisdom tooth impaction were 0.7-4.0 years older than those females with incomplete wisdom tooth impaction, in the male group the age difference was 1.6-2.6 years, the lower level for stage H according to Demirjian was between 18 and 20 years in both genders. It was concluded that in German individuals with stage H according to Demirjian it is most likely that these persons have reached a minimum age of 18 years.  相似文献   

18.
Current social conditions require more accurate methods to determine the age of people, either living or deceased. The aim of this study was to determine chronological age by measuring the mineralization of third molars. Volunteers (n = 137), aged between 14 and 22 years and of either gender, were recruited from north-eastern Mexico. Sampling was probabilistic and at random. The mineralization stage of third molars was evaluated with the use of multi-slice helical computed tomography and the Mincer-modified Demirjian amended scale. The correlation coefficient, mean difference and linear estimation were determined. There was a linear correlation between age and the mineralization of third molars. Third molars of adults had a degree of mineralization above Demirjian stage F, whereas the third molars of minors had stages between A and F. Hence, a method was obtained to determine the chronological age from the evaluation of dental mineralization of third molars by multi-slice helical tomography. These results are useful as a diagnostic support in forensic dentistry.  相似文献   

19.
Radiological assessment of the mineralization stage of third molars is a major criterion for age estimation of living people involved in criminal proceedings. To date insufficient knowledge has been obtained about how the ethnic origin can influence tooth mineralization. A comparative study of wisdom tooth mineralization was carried out on three population samples: one German, one Japanese and one South African. To this end, 3,652 conventional orthopantomograms were evaluated on the basis of Demirjians stages. The Japanese subjects were on average 1–2 years older than their German counterparts upon reaching stages D–F, whereas the South African subjects were on average 1–2 years younger than the Germans when displaying stages D–G. To enhance the accuracy of forensic age estimates based on wisdom tooth mineralization we recommend the use of population-specific standards.  相似文献   

20.
A cross-sectional study was carried out to assess chronological age estimation based on the stages of third lower molar development, following the eight stages (A–H) method of Demirjian et al. The final sample consisted of 1,054 orthopantomograms from Spanish individuals of known chronological age (range 14–21 years) and gender (462 males and 592 females). Results showed a stronger correlation for males (r2=0.54) than for females (r2=0.45). Root formation occurred earlier in males than females, in stages 5, 6 and 7. The mean difference between chronological and estimated age was –0.10 years (±1.23 SD) for left third molar, and –0.07 years (±1.22 SD) for right third molar, with slight variations regarding sex. Comparative tables are provided regarding medicolegal questions concerning age 18 prediction in the Spanish population, showing that legal age is reached in stage 7 (G) by women and in stage 8 (H) by men. No differences have been observed between sides (p<0.0001). Differences were observed between Spaniards and other previously studied populations. Third molar maturity takes place earlier in the Spanish than French-Canadian, Scandinavian, American, German, Japanese and South African populations and is more similar to US Hispanics in root development.  相似文献   

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