Dental age assessment: the applicability of Demirjian's method in south Indian children

Dental age assessment using Demirjian's method on northern Turkish children

Tooth formation is widely used to assess maturity and to predict age. Within clinical dentistry, such information aids in diagnosis and treatment planning. Numerous methods exist that allow either the prediction of age or an assessment of maturation. One widely used method was first described in 1973 by Demirjian et al., as based on a large number of French-Canadian children. The purpose of this study was to evaluate the applicability of Demirjian's method for dental age estimation and for description of mandibular permanent tooth formation in northern Turkish children, 4-12 years of age. Panoramic radiographs of 900 healthy, northern Turkish children, 4-12 years of age were examined with Demirjian's method. Panoramic radiographs were scored by one examiner. Dental age was compared to chronological age by using a paired t-test. The median age for individual teeth for each stage was calculated. The northern Turkish children were generally advanced in dental maturity compared with the children in Demirjian's sample. The mean difference between dental and chronologic ages of boys and girls varied from 0.36 to 1.43 years and 0.50-1.44 years, respectively. The standards of dental age described by Demirjian et al. in 1973 and 1976 may not be suitable for northern Turkish children. Each population of children may need their own specific standard for an accurate estimation of chronological age.

Advanced dental maturation in New Zealand Maori and Pacific Island children

This study employs Demirjian's (1994: CD Rom. Norwood, MA: Silver Platter Education) method for assessing dental maturation to compare the rates of development in children of three ethnic populations living in New Zealand-Maori, Pacific Island, and European. We test the hypothesis that Maori and Pacific Island children will have significantly advanced dental maturation compared with New Zealand children of European extraction. The study population consists of orthopantomographs of 1,343 children (623 females and 660 males) between the ages of 2.5 and 14 years, and involves three ethnic groups-Maori, European, and Pacific Islander. Bland/Altman plots for the mean chronological age against the age difference suggest that dental age as determined by the Demirjian method is consistently lower than the chronological age of the children examined. A mixed model regression analysis shows that this difference between dental and chronological age is significantly greater in Maori than in European children (regression coefficient = 0.414; z = 7.01; P < 0.001) and also significantly greater in Pacific Island children than European children (regression coefficient = 0.574; z = 6.25; P < 0.001). Regression analysis shows that the 50th quantile maturity score of boys and girls differs by 1.49 (t = -6.18, P < 0.01) and the interaction of sex and age is also significantly different (t = -2.44, P < 0.01). Similarly, Maori girls show a difference in maturity score of 1.28 (t = -3.77, P < 0.01). However, the slopes for Maori boys and girls did not differ significantly (age/sex interaction, t = -1.25, P = 0.212). We conclude that Pacific Island children are advanced in dental maturity compared with Maori children who in turn are more advanced than New Zealand children of European origin.

Age Estimation From Root Development of Mandibular Third Molars in Comparison With Skeletal Age of Wrist Joint

Identification of the living person and the dead is of paramount importance for variety of reasons in forensic practice routinely. Age estimation is one of the prime factors employed to establish identity. Estimating age from teeth is generally reliable as they are naturally preserved long after all the tissues and even bones have disintegrated. A study was done to determine the age by root developmental changes, using the intraoral periapical radiographs of the mandibular third molars, adopting the Leif Kullman et al method. Three hundred forty-six girls and 389 boys of the age range 15-25 years, among the South Indian population of young adults from various schools and colleges in the vicinity of Dakshina Kannada and Udupi Districts and also among the patients visiting the outpatient department of Oral Medicine and Radiology, College of Dental Surgery, Manipal, were considered for this study. The subjects were roentgenographically examined to determine the age from the 7 stages of root development of the left mandibular third molar. Depending on the exact stage of root development as seen in the radiograph, the chronologic age was determined. This method sheds a new light on determining the ages of 15, 16, and 18 years, which has an immense medicolegal bearing.

The chronology of third molar mineralization in the Austrian population—a contribution to forensic age estimation

The aim of the present study was to determine the chronology of third molar mineralization and to establish Austrian reference data. Therefore, a cross-sectional study was undertaken by evaluating 610 panoramic radiographs in order to assess the mineralization status of the mandibular third molars of Austrian male and female individuals (275 males and 335 females) between the ages of 12 and 24. The evaluation was carried out using the eight grade scheme of Demirjian et al. (1973). Mean ages, standard deviations, standard errors and percentile distributions are presented for each stage of development. Significant differences between the left and right mandibular third molars were not found. Males reach the developmental stages earlier than females, statistically significant differences were noted in stages E and F. Both mandibular third molars were observed in the majority of the individuals of the Austrian sample (477 individuals, 78.2%). For medicolegal purposes the likelihood of whether an Austrian individual is older than 18 years or not was determined.

Age estimation in children by measurement of open apices in teeth: a European formula

The aim of the present paper was to improve and expand research with a larger number of children from various European countries and to provide a common formula useful for all these countries. Orthopantomographs taken from 2,652 European Caucasian children (1,382 boys, 1,270 girls) aged between 4 and 16 years were analyzed. The children came from Croatia, Germany, Kosovo, Italy, Slovenia, Spain, and the UK. Following the pilot study, subjects' age was modeled as a function of gender (g), morphological variables (predictors) x 5(second premolar), s (sum of normalized open apices) N 0, and the first-order interaction between s and N 0. The results showed that all these variables contributed significantly to the fit, so that all were included in the regression model, yielding the following linear regression formula: Age = 8.387 + 0.282 g - 1.692 x 5 + 0.835 N 0 - 0.116 s - 0.139 s x N 0, where g is a variable, 1 for males and 0 for females. The equation explained 86.1% (R2 = 0.861) of total deviance. The median of the residuals (=observed age minus predicted age) was -0.114 years, with (RefB.2) interquartile range = 1.22 years.

A Test of the Differential Accuracy of the Maxillary Versus the Mandibular Dentition in Age Estimations of Immature Skeletal Remains Based on Developing Tooth Length

Liversidge and colleagues developed a method for predicting the age of immature skeletal remains based on the length of developing teeth. This quantitative method combines dental data from both jaws, except for the permanent lateral incisor, and because there are reasons to suspect that these two types of data are not identical and should not be combined, it raises concerns regarding the accuracy of the technique when applied differently to each jaw. In this study, the differential accuracy of the method was test when applied to the maxillary and mandibular dentition. The test sample is comprised of 57 Portuguese subadult skeletons of known age at death. Results suggest an overall high consistency between estimates obtained from both jaws, but for the permanent dentition only. In the deciduous dentition the age estimates obtained from the maxillary teeth tend to be greater than the age estimates obtained from the mandibular pair, and the differences are significant for the incisors and canine. Additionally, ages obtained from the maxillary deciduous canine also differ significantly from true chronological age. In the permanent dentition there were no differences between the ages provided by both jaws but both the maxillary and mandibular second molars show a significant tendency to underestimate true chronological age. Although this study cannot validate completely the method presented by Liversidge and colleagues, it does provide an important test to its accuracy and calls for further research into its overall performance, particularly with respect to the results obtained from both jaws.

Age estimation in children by measurement of open apices in teeth

This paper concerns a method for estimating the age of children based on their teeth. The sample consisted of 455 Italian white children (213 boys, 242 girls) aged between 5 and 15 years. The purpose of the present investigation was to present a method for assessing chronological age based on the relationship between age and measurement of the open apices in teeth. Pearson's correlation coefficients between age and these variables showed that the correlations between age and the open apices in teeth were significant and negative. Furthermore, gender and the number of teeth with the apical end of the root canals completely closed (N(0)) showed a significant correlation with chronological age. With the aid of a stepwise multiple regression model, a linear relationship between open apices, N(0), and age was shown. Statistical analysis indicated that these morphological variables explain 83.6% of the variations in estimated chronological age. The median of residual errors between the actual and estimated ages was -0.035 years [interquartile range (IQR)=1.18 years].

Non-adult dental age assessment: correspondence analysis and linear regression versus Bayesian predictions

This study focuses on the evaluation of factors influencing the quality (accuracy and reliability) of non-adult dental age assessment from radiographic stages of permanent teeth (excluding the third molar). We used four distinct cross-sectional samples of 1,528 healthy children: 3 of known geographic origin (Ivory Coast, Iran and France) and 1 additional sample of children whose grandparents originated from a different continent. Two different methods of calculations are compared: the correspondence analysis combined with linear regression (CAR) and Bayesian predictions (with no independence assumption). Our results indicate that the quality of age assessment does not seem to depend predominantly on the use of geographic-specific standards. In the case of Bayesian predictions, we observed a clear trend in favour of significantly higher accuracy and reliability levels when using non-geographic-specific standards. One of the main advantage of Bayesian predictions over maximum likelihood methods of estimation is an overall increase in accuracy with high levels of reliability on a fraction of the test sample and, importantly, across all age categories (contrary to methods based on regression analysis). Importantly, in the case of Bayesian non-adult predictions, and contrary to age estimation techniques based on regression, a better quality does not depend on age.

Skeletal age, dental age, and the maturation of KNM-WT 15000

The skeleton of the Homo erectus boy from West Lake Turkana, Kenya (KNM-WT 15000), is remarkably complete, and this individual has thus provided a case study for several researchers examining Homo erectus growth. Using data from a longitudinal study of Montreal French-Canadian children, it is shown that while dental and skeletal ages match reasonably well at the level of a sample of children, individuals can display differences between skeletal and dental ages of 2 years or more. Furthermore, the relationship between these two markers may change over time in individual children. It is also possible to find children with patterns of dental maturation similar to KNM-WT 15000's pattern in the Montreal sample. Therefore, neither the discrepancy between skeletal age and dental age alone nor the pattern of dental maturation as assessed by dental stages precludes a human-like pattern of growth, including an adolescent growth spurt, for this individual. Some indicators (e.g., estimated body size for predicted age, and enamel formation) do suggest possible growth-patterning differences from modern humans, and therefore earlier maturation is a reasonable hypothesis, but caution is warranted, given the large degree of modern human variation in developmental markers and the inherent uncertainty in precise estimation of KNM-WT 15000's maturational parameters.

[Probabilistic approach to age estimation of children by dental maturation]

Two probabilist methods of age prediction in children are proposed: they are both based on the radiological presence of erupted teeth or germs. Using an apprenticeship sample of known age and sex, we established several discriminant models (+/- 13, +/- 16, +/- 18 years old). We also evaluated a Bayesian model with the following age groups: < 13, [13-16[, [16-18[, > or = 18 years old, or [X and Y] years old. When applied on a known test sample, Fisher's linear functions presented a success rate greater than 90%, above 13 years threshold, and below 16 and 18 years thresholds, and Bayesian approach, greater than 85%. Therefore, these methods provide an interesting alternative for children age determination that can be applied in biological and forensic anthropology, too.

New forensic approach to age determination in children based on tooth eruption

The present study proposes equations for age determination both in living and dead children, obtained with the help of stepwise ascending multiple linear regression. The equations should be applied, based on the number of erupted teeth and tooth germs, which were detected on radiographs, during clinical examination and in infant skeletal remains. The proposed equations proved to be efficient just like Demirjian's method used as a reference today, and permit age estimation till 20 years of age.

Assessment of dental maturity of Brazilian children aged 6 to 14 years using Demirjian's method

Dental maturity, often expressed as dental age, is an indicator of the biological maturity of growing children. A method for the assessment of dental maturity was first described by Demirjian, and is widely used and accepted, mainly because of its ability to compare different ethnic groups. This is possible, as the maturity scoring system proposed by the method is universal in application, although the conversion to dental age depends on the population considered.

OBJECTIVES

The aim of this study was to apply Demirjian's method to Brazilian children aged 6-14 years in order to obtain dental maturity curves for each sex, to compare this data with that obtained by Demirjian, and to determine whether there is a significant correlation between dental maturity and body mass index.

METHODS

We retrospectively reviewed the orthopantomograms, height and weight measurements of 689 healthy children. Curves of dental maturity of males and females were constructed.

RESULTS

When compared to the French-Canadian sample of Demirjian, Brazilian males and females were 0.681 years and 0.616 years, respectively, more advanced in dental maturity. There was no significant correlation between dental maturity and body mass index.

Tooth development standards for South Australia

BACKGROUND

Chronological age, as recorded by registration of birth date, is referred to throughout an individual's life. This information is relevant in medical and dental practice for evaluating developmental progress, for educational purposes, and in legal matters, particularly in the application of criminal law. The absence of birth date information raises particular concerns, and estimates of chronological age are often required. Standards of dental maturation may be used to estimate age, but they have been shown to be gender and population sensitive.

METHODS

The revised Demirjian' system of dental age estimation was applied to a sample of 615 South Australian children in order to assess its accuracy.

RESULTS

The results of our study have shown that the Demirjian system is of limited accuracy when used to estimate the age of South Australian children.

CONCLUSIONS

Generation of new standard curves, specific to the Australian population, is indicated.

Growth of permanent mandibular teeth of British children aged 4 to 9 years

PRIMARY OBJECTIVE

The aim of this study was to investigate ethnic differences and describe tooth formation of mandibular permanent teeth in a group of London children.

RESEARCH DESIGN

The design was cross-sectional retrospective study.

SAMPLE AND METHOD

The sample was a non-random group of healthy British children (n = 521) attending a dental hospital. The children aged between 4 and 9 years were of Bangladeshi or white Caucasian origin. Developing permanent mandibular teeth were staged from radiographs according to criteria described by Demirjian, Goldstein and Tanner (1973, Human Biology, 45, 211-227). Data were grouped in 6-month intervals and analysed using probit analysis. Formation was also expressed relative to stages of the first permanent molar (M1) and the distribution of stages tested between the groups and sexes using Mann Whitney U-test.

RESULTS

Tooth formation was not significantly different between the two ethnic groups. Girls attained almost all stages of tooth formation earlier than boys; in addition, the canine showed significant advancement relative to M1 formation in girls (p < 0.05).

CONCLUSIONS

These findings failed to demonstrate an ethnic difference in tooth formation in these children.

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.

Dental maturity in Finns and the problem of missing teeth

Development of teeth was studied from 2483 dental panoramic tomograms of 1651 healthy Finns ranging in age from 2 to 25 years. Dental maturity was assessed using a method based on developmental stages of 7 left mandibular teeth. We give sex-specific tables of maturity scores as a function of ages and of ages as a function of maturity scores. Also generated are percentile graphs for visual evaluations of dental maturity in children and adolescents. Since maturity scales do not tolerate any missing data, a great limitation for their use, we have developed linear regression models for predicting the formation stages of each of the 7 mandibular teeth. It was easiest to predict the formation stage of the mandibular first molars (correct in 87% within the study material) and most difficult to predict second molars and second premolars (correct in 69% and 70%, respectively). We expect the data and formulae presented in this study to prove useful in research and in clinical and forensic dentistry.

Dental maturation in British children: are Demirjian's standards applicable?

OBJECTIVE

The objective of this study was to determine if the standards of dental maturation of Demirjian et al. (1973, 1976) are applicable to British children.

DESIGN

The design was cross-sectional, retrospective.

SAMPLE AND METHOD

The sample comprised 521 London children of Bangladeshi and white Caucasian (English, Welsh and Scottish) origin aged between 4 and 9 years. Dental age was assessed by crown and root stages of seven mandibular teeth from rotational pantomographs. Dental age was compared to chronological age using a t-test.

RESULTS

Differences in dental maturation between the two ethnic groups were not significant. British children as a group were dentally advanced compared to the Canadian standards. The mean (+/- standard deviation) advancement in girls was 0.51 +/- 0.79 years and in boys was 0.73 +/- 0.73 years.

CONCLUSIONS

The standards of dental maturation described by Demirjian et al. (1973, 1976) may not be suitable for British children.