Approaches to chronological age assessment based on dental calcification

The aim of the present study was to find an accurate estimation of chronological age using a small number of selected teeth. For this purpose, the method devised by Nolla [C. Nolla, The development of the permanent teeth, J. Dent. Child. 27 (1960) 254-266.] was used: the development of each of the teeth was determined according to this method on 374 radiographs, 195 of boys (mean age 8.59) and 179 of girls (mean age 8.75). The 28 variables representing the calcification stages were analyzed using cluster analysis followed by multivariate analysis (multiple linear regression model). Patient age was considered to be a dependent variable. Our study showed that antimere teeth are the most homogeneous as regards stages of development. The prediction was more accurate for boys and girls below 10 years of age, using teeth 21, 43 and 46 from boys and teeth 21, 46 and 47 from girls. These teeth accounted for 80% total variance of chronological age for dental calcification. Standard error was +/-1.4 years for boys and +/-1.2 years for girls. When the age of the children remained completely unknown, the best estimates were provided by teeth 43, 47, 46 and 44 from boys and teeth 44, 47 and 43 from girls.     

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.     

Comparison of Age Estimation in Japanese and Scandinavian Teeth Using Amino Acid Racemization*

Abstract: Racemization method is currently considered to be one of the most accurate methods for age estimation. There are many factors that affect racemization reaction velocities. We investigated ethnic differences in the racemization reaction velocities between Japanese and Scandinavian teeth. After a heating experiment, the Arrhenius equation was used to obtain a rate constant (k). Both groups presented almost identical velocities, indicating that there was no difference in the tooth racemization reaction between the two groups. However, because 14 of the 18 Scandinavian teeth had multiple roots, it is possible that accurate racemization rates of the teeth themselves were not reflected in the results. These findings reconfirm that the type of tooth selected is extremely important when evaluating age by racemization.     

Decayed, filled and missing teeth as a forensic-odontologic aid for determining the age above 18 years: A radiographic study of orthopantomograms from a group of teenagers and young adults

The human teeth are a valuable source of information concerning identification and age calculation in forensic sciences. Dental treatment often causes permanent alteration of the teeth, which is visible on radiographs. The correlation of decayed, missing or filled teeth and chronological age has not yet been used for determining the accomplished 18th year of life in teenagers and young adults, e. g. for legal and anthropological purposes. The aim of this study was to determine whether the evaluation of these findings on radiographs correlates with the chronological age in teenagers and young adults. MATERIAL AND METHODS: The dental X-rays (orthopantomograms, OPG) of 1053 outpatients (age: 14 to 24 years) were evaluated. The values "decayed", "missing", or "filled" were recorded for each tooth present. The data were then calculated using statistical tools. RESULTS: The correlation between the number of missing teeth and the chronological age is low. However, the positive predictive value of determining the age of 18 years for certain types of teeth proved to be very high, even up to 100 %. Further, high numbers of filled teeth gave reasonable positive predictive values for an age of 18 years. The number of decayed teeth did not correlate with age. DISCUSSION: This study provides for the first time predictive values for the estimation whether a person is 18 years of age, based on the evaluation of decayed, missing or filled teeth on OPGs only. Whereas the number of patients with such findings is generally low in this age group, some of the positive findings can be used for age estimation as an adjunct to other sources of age calculation. The sole application of these items is not recommended, as sanitary conditions of the teeth depend on both social and individual circumstances. Therefore, the calculated values also reflect the culture of the sample studied. Finally, they are time-dependent and have to be compared to data from other populations. These results have some bearing on the field of forensic odontology.     

A technique to capture, analyze, and quantify anterior teeth rotations for application in court cases involving tooth marks

Anterior teeth within the human dentition have a specific numerical rotation value. Bite marks show an array of angled indentations, abrasions, microlacerations, and contusions. These marks generally represent the incisal surfaces of the suspect's dentition reflecting the rotation values of the teeth in the dental arch. This study described a method for capturing and analyzing anterior dental rotations. The rotations of individual anterior teeth within the study population were categorized as common, uncommon, and very uncommon according to Allen's classification. In the absence of a large number of incisal patterns present in a bite mark, a single but heavily weighted tooth rotation could be of equal discriminatory potential to several common rotation values. No prevalence studies quantifying individual tooth rotations are available. The measurement of each individual tooth rotation together with its individual discrimination potential will enhance the evaluation of the concordant features observed in bite marks.     

Developing permanent tooth length as an estimate of age.

Developing teeth are widely used to predict age in archaeology and forensic science. Regression equations of tooth length for age is a direct method, however, data for permanent teeth is incomplete. The aims of this study were: (a) to calculate regression equations predicting age from tooth length of all permanent teeth from birth to maturity, and (b) to evaluate the difference between radiographic and actual tooth length. The sample studied (N = 76, age range 0 to 19 years) was the Spitalfields juveniles of recorded age-at-death. Tooth length was measured from incisal tip to developing edge of crown or root of 354 dissected teeth. Data for upper and lower teeth were combined except for the lateral incisor. The least squares regression method was used to analyze the data for each tooth type; age being regressed against tooth length for prediction. For most tooth types, growth followed an S-shaped (polynomial) curve with initial fast growth and a further growth spurt around the time of mid root formation. No difference was found between radiographic and true tooth length. These regression equations provide an easy method of predicting age from any developing permanent tooth by measuring tooth length from isolated teeth or from unmagnified, undistorted radiographs.     

The uniqueness of the human anterior dentition: a geometric morphometric analysis

The analysis of bitemarks has a significant bearing on forensic odontology and has attracted an increasingly sophisticated array of techniques in its evaluation. Two postulates underlie all bitemark analyses: firstly, that the characteristics of the anterior teeth involved in the bite are unique, and secondly, that this uniqueness is accurately recorded in the material bitten. Here, we investigate the question of the uniqueness of the anterior dentition. To do this, we use geometric morphometric techniques based on landmark and semilandmark data. The incisor and canine occlusal surfaces of 50 randomly selected orthodontic casts of young individuals (17-20 years) of both sexes form the material for this study. We analyzed the sizes of these teeth by means of landmark and semilandmark analysis to calculate Procrustes distances between tooth outlines. In order to analyze shape variation among individuals, we carried out principal components analyses on the partial warp scores. These are derived from Partial Procrustes coordinates aligned by means of thin-plate spline decomposition based on the bending energy matrix. The results indicate that there is no sexual dimorphism in the shape of the upper or lower arches. Plots of centroid size and first relative warps show less superposition among individuals than in shape analysis. This means that, when the size and shape are considered together, the difference between arches increases. Procrustes superimposition between the two individuals located most closely (0.0444) and the two most separated (0.1567) along the first axis of relative warp analyses show that individuals are not only differentiated by the relative position of their teeth but also by their arch shape. In conclusion, it appears that the incisal surfaces of the anterior dentition are in fact unique.     

Prosthetic restorations, dental root fillings and periodontal bone resorptions as a forensic-odontologic aid for determining the age above 18 years: A radiographic study of orthopantomograms from a group of teenagers and yount adults

The human teeth are a valuable source of information concerning identification and age calculation in forensic sciences. Dental treatment often causes permanent alteration of the teeth, which is visible on radiographs. The correlation of prosthetic restorations, root canal fillings and periodontal bone loss with chronological age has not yet been used for determining the completed 18th year of life in teenagers and young adults, e. g. for legal and anthropological purposes. The aim of this study was to determine whether the evaluation of such findings on radiographs correlates with the chronological age in teenagers and young adults. MATERIAL AND METHODS: The dental X-rays (orthopantomogram, OPG) of 1053 outpatients (age: 14 to 24 years) were avaluated. The values "prosthetically restored", "filled dental root", or "periodontal bone loss" were recorded for each tooth present. The data were then evaluated using statistical tools. RESULTS: The correlation between the number of prosthetically restored teeth and the chronological age is high. The positive predictive value of determining an age of at least 18 years proved to be very high. However, these findings are rarely present in this age group. The number of endodontically treated teeth correlated less exactly with age. On the other hand, the determination of periodontal bone loss gave reasonable positive predictive values for the threshold value "chronological age of 18 years or more". DISCUSSION: This study provides for the first time predictive values for the estimation whether a person is 18 years of age, based on the evaluation of teeth with prosthetic restorations, root canal fillings or periodontal bone loss on OPGs only. Whereas the number of patients with such findings is generally low in this age group, some of the positive findings can be used for age estimation as an adjunct to other sources of age calculation. The sole application of these criteria is not recommended, as sanitary conditions of the teeth depend on both social and individual circumstances. Therefore, the calculated values also reflect the culture of the sample studied. Finally, they are time-dependent and have to be compared to data from other populations. These results have some bearing on the field of forensic odontology.     

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.     

Digital reconstruction of fragmented tooth remains in forensic context

Forensic odontology majorly focuses on the identification of victims through the analyses of oral and para-oral structures.Exposure to high temperatures and trauma can occur in mass disasters and may lead to the fracturing and fragmentation of teeth.These fragments may become very fragile and easily damaged while handling.Conventional methodologies such as the use of transparent nail polish,hair spray,cyanoacrylate or adhesives have been used to stabilise the fragmented pieces.This study introduces a new and innovative digital technique that utilises three-dimensional surface scanning(3DSS)and rapid prototyping techniques to reconstruct fractured portions of the teeth.The results of qualitative congruency analysis suggest that over all variance of morphological error(0.0526±0.05)mm.These results imply that the reconstructed 3D model can be used for various morphometric analyses.     

Application of aspartic acid racemization to forensic odontology: post mortem designation of age at death

The extent of racemization of aspartic acid in the dentin of healthy, carious and impacted teeth was used to define the ages of individuals at the time of their death. These determinations were performed with an error of +/- 4 years. This method holds the promise of simplifying procedures in, and extending the application of forensic odontology. The current error range of this method may be reduced by analyzing teeth of the same positional types from deceased individuals of known age. Using this method, it appears that post mortem preservation of up to 10 years has a negligible effect on the values determined for the age of individuals at death.     

An application of D- and L-aspartic acid mixtures as standard specimens for the chronological age estimation

Instead of using the control teeth, we tried to prepare standard specimens to derive the equations for calculation of the age (analytical curves) with respect to each kind of tooth of various ages. To prepare standard specimens, we determined the racemization ratio of the teeth of known age that had actually been used for the appraisal of chronological age (total control teeth). Then we mixed commercially available L-Asp and D-Asp in the same D/L ratio as the measured one in the total control teeth. As a result, we were able to obtain the racemization rate equations from the age-specific standard specimens of central and lateral incisors. These equations were closely similar to those derived from actual teeth of known age. Since the racemization rate equations obtained from the standard specimens were satisfactorily reproducible, we assumed that these equations could be used in place of those obtained from the control teeth. Actually, in the age estimation of unidentified corpses from teeth, the use of standard specimens enabled us to estimate the age almost as precisely as estimated using the control teeth. Thus, the present study has demonstrated that in the estimation of chronological age the control teeth can be substituted by the standard specimens. This shows the possibility of using the standard specimens also in other laboratories where the racemization ratio can be measured with sufficient reproducibility.     

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

Estimation of age-at-death for skeletonised forensic remains is one of the most significant problems in forensic anthropology. The majority of existing morphological and histological techniques are highly inaccurate, and show a bias towards underestimating the age of older individuals. One technique which has been successful in forensic age estimation is amino acid racemization in dentine. However, this method cannot be used on remains where the post-mortem interval is greater than 20 years. An alternative approach is to measure amino acid racemization in dental enamel, which is believed to be more resistant to change post-mortem. The extent of amino acid racemization in the acid soluble fraction of the enamel proteins was determined for modern known age teeth. A strong correlation was observed between the age of the tooth and the extent of racemization. No systematic bias in the direction of age estimation errors was detected. For the majority of teeth analyzed, the presence of dental caries did not affect the results obtained. In a minority of cases, carious teeth showed a higher level of racemization than would be expected given the age of the individual. These results indicate that amino acid racemization in enamel has the potential to be used in age estimation of skeletal remains.     

Age estimation in small children: reference values based on counts of deciduous teeth in Finns

The eruption of teeth in the mouth is suitable for age estimations during the period when teeth are actively emerging, in the deciduous dentition phase approximately from the age of 6 months to 2.5 years. Estimations of age can be performed simply by counting the number of teeth in the mouth. Reliability of the estimates depends on the reference data available and each population group should preferably have its own standards. In the present study timing of eruption of successive deciduous teeth was studied longitudinally in 129 Finns. The dates of clinical eruption of deciduous teeth were recorded by mothers and checked by dentists. In 40 of the 129 children emergence ages of at the most the four last teeth were based only on semiannual registrations performed by dentists. The main purpose was to provide normal timetables of tooth eruption in small children in forms that are practical in estimations of dental age. No sexual dimorphism existed in the timing of clinical eruption of successive deciduous teeth. The mean age corresponding to the presence of one tooth in the mouth was 7.1 months (S.D.=1.78) and that corresponding to tooth count 19 was 27.8 months (S.D.=3.99). If the chronological age is known, the presented distributions and means with variations make it possible to estimate the degree of advancement or delay in a child’s dental development. If the age of the child is not known, the mean and median ages can be used for estimations of chronological age. However, estimations of age should not be based only on tooth counts because of marked variation also within this homogeneous group.     

Age estimation in small children: reference values based on counts of deciduous teeth in Finns

The eruption of teeth in the mouth is suitable for age estimations during the period when teeth are actively emerging, in the deciduous dentition phase approximately from the age of 6 months to 2.5 years. Estimations of age can be performed simply by counting the number of teeth in the mouth. Reliability of the estimates depends on the reference data available and each population group should preferably have its own standards. In the present study timing of eruption of successive deciduous teeth was studied longitudinally in 129 Finns. The dates of clinical eruption of deciduous teeth were recorded by mothers and checked by dentists. In 40 of the 129 children emergence ages of at the most the four last teeth were based only on semiannual registrations performed by dentists. The main purpose was to provide normal timetables of tooth eruption in small children in forms that are practical in estimations of dental age. No sexual dimorphism existed in the timing of clinical eruption of successive deciduous teeth. The mean age corresponding to the presence of one tooth in the mouth was 7.1 months (S.D.=1.78) and that corresponding to tooth count 19 was 27.8 months (S.D.=3.99). If the chronological age is known, the presented distributions and means with variations make it possible to estimate the degree of advancement or delay in a child's dental development. If the age of the child is not known, the mean and median ages can be used for estimations of chronological age. However, estimations of age should not be based only on tooth counts because of marked variation also within this homogeneous group.     

Diversity of dental patterns: application on different ages using the Brazilian National Oral Health Survey

Methods of individual identification using human remains are widely used in forensic anthropology; however, there are few studies that use statistical methods in order to obtain a correct definition of parameters. The objectives of the study were to verify the diversity of dental patterns in the Brazilian population and analyse its application on different ages. Data from the Brazilian National Oral Health Survey were used to verify the presence and absence of dental treatment among 35,613 individuals of several age groups: 15-19, 35-44 and 65-74. Information referring to every dental element was described: higid (H), decayed (D), filled (F), missing (M) and prosthesis (P). Coincidences that were observed in pairs of homologous teeth were analysed according to clinical situation, gender and age. Ordinary findings (presented in more than 10% of pairs) and extraordinary ones (presented in less than 10% of pairs) were described. Total and conditional diversity estimates were performed. Among adolescents, H were the most frequent teeth, and the first molar teeth were the ones presenting less frequency of H. Among adults, the frequency of M teeth among females ranged from 15.17% to 71.59%, and among males they ranged from 9.00% to 87.20%. Among the elderly, M teeth were observed in the largest frequency, and anterior teeth presented fewer losses than posterior ones. M was the condition that most coincided with both sides in the elderly. In adults, some pairs of teeth presented H, but mostly pairs of teeth presented as M. Among adolescents, there was more concordance of the H component. Among male and female adolescents, we observed extraordinary findings in DMFP dental conditions in most of the teeth. Among adults, the less frequent dental condition was P, which was found in several teeth. The extraordinary findings among elderly male teeth were codes H, D, F and P; among females, they were H, D, F and P codes. The high prevalence of healthy teeth in adolescents and a high rate of edentulism in the elderly interfered with the analysis performed. However, when an estimation of diversity that corrects those distortions was used, all of the groups presented satisfactory results that were homogeneous in the performed analysis.     

Tooth eruption times of permanent teeth in male and female adolescents in Niedersachsen

The aim of this study was to determine the eruption times of permanent teeth, excluding third molars, in a defined area population of a country district in Lower Saxony. The authors investigated 2495 oral findings of 664 patients (male 315, female 349) in a longitudinal study. The minimum age was 3.00 years and the maximum age 24.00 years. The dental findings were collected over a period of about 20 years (1980-2002). The oral findings per child/adolescent were assessed between one and 16 times. The eruption times of teeth in females are earlier than those for the same teeth in males. Further, the permanent dentition in females is completed earlier than in males. The tooth eruption occurs symmetrically in both jaws. The comparison of both jaws revealed a slightly advanced eruption of the lower jaw teeth for both sexes. There is a noteworthy change in the eruption sequence of the teeth. In contrast to other reports we determined that the eruption of the canine proceeds the eruption of the second premolar. We found no acceleration of the dentition when compared to other reports and confirmed the rules of tooth eruption in man. Oral examination of teeth is a simple tool to calculate tooth eruption intervals. This first investigation on a population of Lower Saxony revealed a change in the eruption sequence of permanent teeth. The findings are relevant for dental treatment planning and should be reconfirmed at certain intervals.     

Age estimation methods using anthropological parameters on human teeth-(A0736)

The research was conducted on the 160 intact extracted human teeth with one and two roots of the known age and sex. The teeth were disinfected, dried and X-rayed. After that the section of the longitudinal cut through the teeth was performed in order to facilitate monitoring of all tissues and morphological characteristics of the teeth. The age was determined in three ways: Method 1 [G.Bang, E. Ramm, Determination of age in humans from root dentin transparency, Acta Odontol. Scand. 28 (1970) 3-35]--analysis of the translucency of the root dentine, Method 2 [S. Kvaal, T. Solheim, A non-destructive dental method for age estimation, J. Forensic Odonto-stomatol. 12 (1994) 6-11]--analysis of the root and the root canal from the X-ray, Method 3 [G. Johanson, Age determination from human teeth, Odontol. Revy. 22 (1971) 1-126]--analysis of six parameters on each teeth. All data were subject to the correlation and regression analysis which showed the following: all of the three applied methods were in the significant correlation with the real age, and the best of them proved to be Method 3 where the coefficient of correlation was 0.85, p<0.001. The teeth of the maxilla are more convenient for the age determination than the teeth of mandible. They are in the significant strong correlation with the known real age, and in Method 3, the coefficient of correlation is 0.78, p<0.001. Age determination of the teeth with two roots is in significant correlation with the known real age p<0.001 in relation to the determined age on the teeth with one root. The results show that sex too, is in significant correlation with the real age, p<0.001. In practice, the methods used and the results achieved in this research have been enabling the dental age estimation of human remains from mass graves after the 1991 war in Croatia.