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.     

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).     

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。     

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 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.     

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.     

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.     

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。     

运用牙齿影像学方法推断年龄的研究进展

本文对国内外文献在利用牙齿的影像学检查推断幼儿、青少年和成人年龄的方法、特点和优缺点进行了归纳和综述。     

A new biochemical method for estimation of postmortem time.

Hypoxanthine (Hx) is formed by hypoxic degradation of adenosine monophosphate (AMP) and might be elevated due to antemortem hypoxia. However, it also increases after cessation of the life processes. Until now measurements of potassium in corpus vitreous humor have been used by forensic pathologists to determine postmortem time. In this study the influence of postmortem time and temperature on vitreous humor Hx and potassium levels were compared. Repeated sampling of vitreous humor was performed in 87 subjects with known time of death and diagnosis. The bodies were kept at either 5 degrees C, 10 degrees C, 15 degrees C or 23 degrees C. Hx was measured by means of HPLC and potassium by flame photometry. In 19 subjects from whom samples were obtained within 1.5 h after death, the normal level of Hx could be estimated to be 7.6 mumol/l and that of potassium to be 5.8 mmol/l. The spread of the potassium levels measured shortly after death was much greater than for the corresponding Hx levels. In the four temperature groups the Hx level increased 4.2, 5.1, 6.2 and 8.8 mumol/l per h, respectively, whereas the corresponding figures for potassium were 0.17, 0.20, 0.25 and 0.30 mmol/l per h. The vitreous humor concentration of both Hx and potassium increases fairly linearly after death. The slopes are steeper with increasing temperature. Since the scatter of the levels is greater for potassium than for Hx, the latter parameter seems to be better suited for the determination of time of death in cases without antemortem hypoxia, especially during the first 24 h.     

Racemization of aspartic acid from human dentin in the estimation of chronological age

The estimation of chronological age in cadavers, human remains and in living human beings by various methods is discussed. These methods, which are based on the age dependent non-enzymatic changes of l-form amino acids to d-form amino acids, mainly aspartic acid, are among the most reliable and accurate methods to date. Most of these methods use gas chromatography (GC). In this review, results of aspartic acid racemization in dentin at different targets are discussed. In addition, pre-considerations and guidelines are given for the selection of dentin from teeth. A pilot project was run to evaluate the efficiency of high performance liquid chromatography (HPLC) coupled with fluorescence detection. New buffer conditions were found to obtain stable derivatives of aspartic acid enantiomers for the estimation of racemization.     

The accuracy of three methods of age estimation using radiographic measurements of developing teeth

The accuracy of age estimation using three quantitative methods of developing permanent teeth was investigated. These were M?rnstad et al. [Scand. J. Dent. Res. 102 (1994) 137], Liversidge and Molleson [J. For. Sci. 44 (1999) 917] and Carels et al. [J. Biol. Bucc. 19 (1991) 297]. The sample consisted of 145 white Caucasian children (75 girls, 70 boys) aged between 8 and 13 years. Tooth length and apex width of mandibular canine, premolars and first and second molars were measured from orthopantomographs using a digitiser. These data were substituted into equations from the three methods and estimated age was calculated and compared to chronological age. Age was under-estimated in boys and girls using all the three methods; the mean difference between chronological and estimated ages for method I was -0.83 (standard deviation +/-0.96) years for boys and -0.67 (+/-0.76) years for girls; method II -0.79 (+/-0.93) and -0.63 (+/-0.92); method III -1.03 (+/-1.48) and -1.35 (+/-1.11) for boys and girls, respectively. Further analysis of age cohorts, found the most accurate method to be method I for the age group 8.00-8.99 years where age could be predicted to 0.14+/-0.44 years (boys) and 0.10+/-0.32 years (girls). Accuracy was greater for younger children compared to older children and this decreased with age.     

The application of amino acid racemization in the acid soluble fraction of enamel to the estimation of the age of human teeth

The main objectives of the European project "Collaborative Harmonization of Methods for Profiling of Amphetamine Type Stimulants" (CHAMP) funded by the sixth framework programme of the European Commission, included the harmonization of MDMA profiling methods and the creation of a common database in a drug intelligence perspective. In the preliminary stages of this project, the participating laboratories analysed the physical characteristics, the chemical composition and the organic impurities of MDMA tablets, using the previously harmonized methods. The aim of the present work was to apply statistical treatments to the recorded data in order to evaluate their potential in the fight against drug trafficking. Comparable working procedures were applied on the different types of data. The first part of this article deals with organic impurities data, while the second part focuses on the potential of the physical characteristics. Organic impurities data were recorded by a harmonized Gas Chromatography/Mass Spectrometry (GC/MS) method previously developed. Statistical analysis provided a selection of pertinent variables among the 46 organic impurities identified in the chromatograms. Correlation coefficients were used to yield separation between populations of samples coming from the same synthesis batch and samples coming from different batches. It was shown that correlation measurements based on Pearson and cosine functions applied to the data pre-treated by normalisation to the sum of peak responses followed by the square root provided an excellent discrimination between the two populations. The statistical methods applied to organic impurities profiles proved to be excellent techniques to differentiate samples from different batches and to highlight operational links between samples.