Application of three dental methods of adult age estimation from intact single rooted teeth to a Peruvian sample

Methods of estimating adult age at death from such dental features as root translucency, root length, and the extent of periodontosis in intact single rooted teeth have proven useful in studies of modern individuals, especially in estimating age in older adults. Questions remain however, concerning the impact of regional and population variation on accuracy. To examine this issue, three approaches to age estimation were applied to a diverse sample of 100 individuals from Peru. Mean errors of estimation for all three approaches were similar to those originally reported, suggesting minimal impact of population variation of the features measured. A new regression equation, specifically for Peruvian samples, is provided.     

A modified Gustafson method of age estimation from teeth

Modifications to the Gustafson method of age estimation from teeth are described. They are designed to minimise the subjective nature of the scoring technique and to quantify the regressive changes in the enamel, dentine and cementum. Randomly selected teeth from 25 Indians were examined by the Gustafson method and by our own modification. It was shown that our modified method resulted in more accurate and reproducible age estimations than did the original method.     

Age estimation from the structure of adult human teeth: review of the literature.

The literature on age estimation from the structure of adult human teeth is reviewed. Several anatomic changes of teeth have been shown to be valuable in age determination, but there is still controversy concerning the accuracy of cemental annulation. It is believed that improvements in age estimation can be made using direct measurement rather than scoring systems.     

A new method of age estimation based on the changes in human non-collagenous proteins from dentin

The new method exploits the characteristic of staphylococcal protease V8, which specifically splits peptide bonds where l-glutamic or l-aspartic acid participate. Those peptide bonds where d-aspartic acid is present remain unsplit because of the stereospecifity of enzymes. In accordance with expectations, fewer peptide bonds are split by this protease at more advanced ages and larger peptide fragments are thus formed due to the higher content of d-amino acid residues in the proteins of older people. The samples of acid-extracted non-collagenous proteins from dentin were separated using high performance liquid chromatography after enzymatic hydrolysis. A peak with a retention time of 45.3 min was chosen and his enlarging area showed a linear correlation with increasing age. Although the linear correlation with age was proved, the scattering of values decreases the usefulness of the proposed method for age estimation.     

Permanent teeth development in a Spanish sample. Application to dental age estimation

The purpose of this study is to clarify the chronology of different stages of dental development, according to Demirjian, in a sample of Spanish children, which will enable us to build a database that will be used as a reference in regard to the dental development of individuals of our socio-geographic environment. In the same studied sample, a calculation of the dental age according to Demirjian was carried out. This study was conducted in a final sample consisting of 1010 orthopantograms, corresponding to Spanish children (485 boys and 525 girls) ages 2-16. Comparing the age of onset of the different stages among the children, evidence was found that girls had an earlier general development than boys. These differences were only statistically significant in teeth and concrete stages. The canine teeth revealed greater gender dimorphism, with significant differences in all stages compared with the upper canines. The method proposed by Demirjian for dental age calculation resulted in a significant overestimation of dental age in relation to the chronological age in boys (average of 0.87 years) and girls (average of 0.55 years). Data from this study may be used as reference for dental maturity, as well as a standard for estimating age in Spanish children.     

Gelatinase A in human dentin as a new biochemical marker for age estimation

Dentin proteins from 24-individual permanent molars from patients aged 15 to 73 years were sequentially extracted, with guanidinium chloride (G1-extract) and then with EDTA; after demineralization, the material was again extracted with guanidinium chloride (G2-extract). Extracts were analyzed by SDS-PAGE electrophoresis and the gels were processed for zymography to detect gelatinolytic activities. The patterns of gelatinase A distribution differed in the different dentin protein fractions, and the changes varied with age. Significant differences were detected in gelatinase A in G2-extracts between individual younger than 20 years old and the rest of the sample (chi2exp = 19.429; 1 d.f.; p < or = 0.001). The incidence of true and false positives and negatives, and sensitivity and specificity for the presence of gelatinase A in dentin extracts, were calculated. Determination of gelatinase A in human dentin may be a useful marker to estimate age, especially when other morphological methods are of limited usefulness.     

应用Demirjian法进行法医学年龄推断的评价

目的对应用Demirjian法进行法医学年龄推断的准确度及可靠性进行初步评价。方法应用Demirjian法测定828名上海地区青少年(男279名,女549名,11～19周岁)的牙龄,比较所测牙龄和实际年龄的差异。结果在11～14岁年龄段Demirjian法测定的牙龄比实际年龄高估,在15～16岁年龄段低估,在17岁及17岁以上年龄段具有局限性。结论Demirjian法可以用于测定上海地区11～16岁年龄段青少年的牙龄,使用时需进行适当的修正。     

A simple technique for age estimation in adult corpses: the two criteria dental method.

A method for age determination of adults from single rooted teeth is presented. It is based on the measurement of two dental features: periodontosis height times 100/root height (P) and transparency of the root height times 100/root height (T). These measurements are made on the labial surface of the entire tooth without section and do not require special equipment or training. The application of multiple regression analysis to a working sample of 306 teeth of known age, sex and race provided the following equation: Age (years) = 0.18 x P + 0.42 x T + 25.53. The mean error between the actual and estimated age was +/- 10 years on the working sample and +/- 8.4 years on a control sample made of 45 forensic science cases. Upper incisors showed a better precision than the other single rooted teeth and accuracy was not sex related. A comparison of the Gustafson and Lamendin methods on a control sample of 39 teeth resulted in an advantage of the latter considering the mean error on the estimation (14.2 +/- 3.4 years for Gustafson versus 8.9 +/- 2.2 for Lamendin). The Lamendin method can be practical interest for any forensic pathologist or dentist as it is fast, easy to use, and reasonably accurate except for cases of individuals under age 40 where other methods must be preferred.     

Accuracy of age estimation of radiographic methods using developing teeth

Developing teeth are used to assess maturity and estimate age in a number of disciplines, however the accuracy of different methods has not been systematically investigated. The aim of this study was to determine the accuracy of several methods. Tooth formation was assessed from radiographs of healthy children attending a dental teaching hospital. The sample was 946 children (491 boys, 455 girls, aged 3-16.99 years) with similar number of children from Bangladeshi and British Caucasian ethnic origin. Panoramic radiographs were examined and seven mandibular teeth staged according to Demirjian's dental maturity scale [A. Demirjian, Dental development, CD-ROM, Silver Platter Education, University of Montreal, Montreal, 1993-1994; A. Demirjian, H. Goldstein, J.M. Tanner, A new system of dental age assessment, Hum. Biol. 45 (1973) 211-227; A. Demirjian, H. Goldstein, New systems for dental maturity based on seven and four teeth, Ann. Hum. Biol. 3 (1976) 411-421], Nolla [C.M. Nolla, The development of the permanent teeth, J. Dent. Child. 27 (1960) 254-266] and Haavikko [K. Haavikko, The formation and the alveolar and clinical eruption of the permanent teeth. An orthopantomographic study. Proc. Finn. Dent. Soc. 66 (1970) 103-170]. Dental age was calculated for each method, including an adaptation of Demirjian's method with updated scoring [G. Willems, A. Van Olmen, B. Spiessens, C. Carels, Dental age estimation in Belgian children: Demirjian's technique revisited, J. Forensic Sci. 46 (2001) 893-895]. The mean difference (+/-S.D. in years) between dental and real age was calculated for each method and in the case of Haavikko, each tooth type; and tested using t-test. Mean difference was also calculated for the age group 3-13.99 years for Haavikko (mean and individual teeth). Results show that the most accurate method was by Willems [G. Willems, A. Van Olmen, B. Spiessens, C. Carels, Dental age estimation in Belgian children: Demirjian's technique revisited, J. Forensic Sci. 46 (2001) 893-895] (boys -0.05+/-0.81, girls -0.20+/-0.89, both -0.12 y+/-0.85), Demirjian [A. Demirjian, Dental development, CD-ROM, Silver Platter Education, University of Montreal, Montreal, 1993-1994] overestimated age (boys 0.25+/-0.84, girls 0.23+/-0.84, both 0.24 y+/-0.86), while Nolla [C.M. Nolla, The development of the permanent teeth, J. Dent. Child. 27 (1960) 254-266] and Haavikko's [K. Haavikko, The formation and the alveolar and clinical eruption of the permanent teeth. An orthopantomographic study, Proc. Finn. Dent. Soc. 66 (1970) 103-170] methods under-estimated age (boys -0.87+/-0.87, girls -1.18+/-0.96, both -1.02 y+/-0.93; boys -0.56+/-0.91, girls -0.79+/-1.11, both -0.67 y+/-1.01, respectively). For individual teeth using Haavikko's method, first premolar and second molar were most accurate; and more accurate than the mean value of all developing teeth. The 95% confidence interval of the mean was least for mean of all developing teeth using Haavikko (age 3-13.99 years), followed by identical values for Demirjian and Willems (sexes combined).     

A method of age estimation using Raman microspectrometry imaging of the human dentin

The aim of this work is to establish a correlation between ageing and Raman spectra imaging of human teeth. Raman spectrum of an analysed sample is characteristic of its chemical components. By exploring the different dentinal areas on each tooth, we sought to find a correlation between noticeable variability on Raman spectra and the stages of dentinal evolution with advancing age. A study on 30 teeth analysed by Raman microspectrometry was used to select predictors of age, and it allowed us to determine a regression formula, with age as a dependent variable. Our data were computed by means of a statistical method called partial least squares (PLS) regression. This method was specially adapted for this kind of situation, where we have numerous predictors and relatively few observations. The regression formula was performed on a test sample of four more teeth, and we obtained a correct age estimation, with a mean error of more or less than 5 years. The main benefits of this method was a minimal and non-destructive tooth preparation, which led to an efficient age prediction, for any age group.     

根据维吾尔族牙磨耗度推断年龄的研究

收集新疆维吾尔族 2 80例牙磨耗度的资料 ,应用多元逐步回归方法获得 3 4个推断年龄回归方程。为应用方便 ,将这些方程转化成推断年龄表。回归方程的相关系数 (R)为 0 71～ 0 92 ,Fs =3 4～ 5 44>F0 0 1,t =17～ 2 5 >t0 0 1,则P <0 0 1。与实际年龄相比 ,其准确性为 3 7 5 0 %～ 65 3 6%± 3岁 ,5 6 73 %～ 78 93 %± 5岁 ,73 93 %～ 88 5 %± 7岁。     

Application of automatic image analysis (IBAS system) to age calculation. Efficiency in the analysis of several teeth from a single subject.

In a previous paper (M. López-Nicolás et al., Forensic Sci. Int., 45 (1990) 143-150) we obtained a model of multiple regression to estimate age using computerized image analysis (IBAS) to study teeth. This method should provide more precise measurements of the parameters involved and to test this hypothesis we have carried out a blind study using more than one tooth from the same individual in order to check the diagnostic accuracy of the method. Our results show that individual variability introduced serious errors in tooth age estimation using computerized image analysis. However the study of more than one tooth per individual improves the accuracy of age estimation. Specific cases should therefore be interpreted cautiously, as a degree of variability can be expected using the parameters defined in this method.     

Dental age estimation through volume matching of teeth imaged by cone-beam CT

A custom-made voxel counting software for calculating the ratio between pulp canal versus tooth volume based on cone-beam CT tooth images was developed and evaluated. The aim of this study was to attempt establishing a correlation between the chronological age of a certain individual and the pulp/tooth volume ratio of one of the teeth. Twenty-eight single rooted teeth of 19 individuals with well-known chronological age were scanned by the cone-beam CT (3D Accuitomo, J. Morita, Kyoto, Japan). Next the images were analyzed using the custom-made software. Linear regression analysis was performed. The results of the analysis showed a moderate correlation between the pulp/tooth volume ratio and biological age with a coefficient of determination (R2) of 0.29. Although the present work was limited to a pilot study, the developed technique showed promising results for dental age estimation in a non-invasive manner using cone-beam CT images in living individuals.     

Application of Kvaal et al.'s age estimation method to panoramic radiographs from Turkish individuals

Age estimation of living adult individuals can be accomplished with limited methods. Radiographic dental methods based on the pulpal narrowing with secondary dentin formation have been presented. In the present study, Kvaal et al.'s method, one of the radiographic dental age estimation methods, was applied to panoramic radiographs from Turkish individuals. The correlation between chronological and estimated ages was examined and the feasibility of length and width measurements of pulp cavity was evaluated for age estimation. The study population consisted of 123 patients with ages ranging from 14 to 57 years. The measurements of the length and width of six types of teeth on digitized panoramic radiographs were performed, and the ratios between tooth and pulp cavity measurements were calculated. Age was estimated using the linear regression models presented by Kvaal et al. and Paewinsky et al. High differences were observed between chronological and estimated ages. Measurement ratios showed no significant or weak correlation with age. The linear regression models were derived using variables that were significantly correlated with age. The determination coefficients of the models varied from 0.035 to 0.345. In conclusion, a difference of more than 12 years in the chronological and estimated ages derived using regression models in literature was found on panoramic radiographs in Turkish individuals. The length and width of the pulp cavity, measured according to the method of Kvaal et al. using panoramic radiographs, were insufficient to precisely estimate the age of Turkish individuals.     

Age estimation by measurements of developing teeth: accuracy of Cameriere's method on a Brazilian sample

Developing teeth are commonly the criteria used for age estimation in children and young adults. The method developed by Cameriere et al. (Int J Legal Med 2006;120:49-52) is based on measures of teeth with open apex, and application of a formula, to estimate chronological age of children. The present study evaluated a sample of panoramic radiographs from Brazilian children from 5 to 15 years of age, to evaluate the accuracy of the method proposed by Cameriere et al. The results has proven the system reliable for age estimation, with a median residual error of -0.014 years between chronological and estimated ages (p = 0.603). There was a slight tendency to overestimate the ages of 5-10 years and underestimate the ages of 11-15 years.     

Pink teeth in a series of bodies recovered from a single shipwreck

Pink teeth have most often been observed in victims of drowning but have also been reported in subjects who died suddenly and unnaturally. There is general agreement that there is no obvious connection between the occurrence of pink teeth and the cause of death, but the condition of the surroundings (especially humidity) must certainly play an important role in the development of the pink-tooth phenomenon. The frequency and distribution of postmortem pink coloration of the teeth have been studied among a representative sample of 52 cadavers. All the bodies were victims of a single shipwreck that occurred on March 13, 1997, in the middle of the Otranto Canal (Mediterranean Sea). The bodies were recovered from the seawater after approximately 7 months. A distinct pink coloration of the teeth was found in only 18 cadavers (13 females and 5 males) of ages ranging between 13 and 60 years. The phenomenon was more pronounced in younger individuals due to age-related changes of the root canal, less penetrable by the pigment responsible for the postmortem pink staining. By histochemical methods and autofluorescence, hemoglobin and its derivatives have been identified as the most likely pigments responsible for this postmortem process that can be considered analogous to postmortem lividity. These data are consistent with previous reports on pink teeth, indicating that the diffusion of the blood in the pulp into the dentinal tubules causes the red discoloration of the teeth. Based on the results, the pigmentation is more prominent on the teeth with single roots rather than in the posterior teeth with multiple roots.     

成像技术用于锁骨年龄推断的研究进展

锁骨内侧端和肩峰端随年龄变化具有一定规律性,尤其是内侧端骨骺愈合程度,对于30岁以下的年龄推断具有重要价值。国内外法医人类学家对锁骨大体解剖及影像特点进行了大量研究,积累了丰富的科研和应用基础。CT和MRI等影像新技术的应用将有望提高锁骨年龄推断的准确性。