The timing of permanent tooth development in a Black Southern African population using the Demirjian method

Comparing tooth development timing between ethnic groups, excluding nutritional and environmental influences

The timing of dental development in ethnic Finns and Somalis, who were born and living in Finland, was compared, with efforts to minimize environmental bias. The developmental status of seven lower left permanent teeth were staged according to Demirjian et al., using panoramic radiographs from 2,100 Finnish and 808 Somali females and males, aged 2 to 23 years. For each tooth, a continuation-ratio model was constructed to analyze the allocated stages as a function of sex and ethnic origin. Several statistically significant differences in mean age of certain tooth developmental stage transitions were revealed. While Somalis generally displayed stage transitions at younger age, none of the seven teeth consistently showed earlier stage transitions in Somalis compared to Finns. Within each tooth, the lowest (or highest) mean age of stage transition varied without any discernible pattern between the two ethnic groups. Overall, the observed differences in mean age of stage transition between the groups was minimal, suggesting a low impact on clinical and forensic age assessment practice. In conclusion, the studied ethnic Finn and Somali groups with equal nutritional and /or environmental conditions exhibit similar timing in the development of all lower left permanent teeth.

Comparison of Demirjian's comprehensive chart with the London atlas of tooth development in children and adolescents: a pilot study

Dental age estimation has its application in various subdisciplines of medicine and dentistry. New methods of dental age (DA) estimation are emerging and it is important that we compare different methods to determine which one is more closely related to the chronological age. Demirjian's method is one of the most widely used techniques and has been tested in various ethnic populations globally. In 2016, another approach to DA estimation is the London atlas of human tooth development and eruption. No study has compared Demirjian's comprehensive chart and London atlas method in the Indian population. Hence, in the current study, we estimated DA using Demirjian's comprehensive chart and London atlas method for association with the known chronologic age in children and adolescent population. The study also attempted to determine if sexual dimorphism existed in DA estimated by the two methods. Estimation was performed for both methods on 100 orthopantomogram records (50 males and 50 females, aged 6-16 years) of orthodontic patients. The data were compared and analysed using paired t-tests. There was an overestimation of DA by Demirjian's comprehensive chart on an average of +1.3 years in males and +0.5 years in females, whereas using London atlas, it was +1.4 years in males and +0.5 years in females. The mean of underestimation was -0.6 years in males and -0.8 years in females using Demirjian's comprehensive chart, whereas it was -0.8 years in males and -0.5 years in females. A statistically significant difference (P < 0.0001) was found when mean chronological age (11.6 ± 2.6) years of the participants was compared with DA estimated using either Demirjian's comprehensive chart (12.3 ± 2.8) years or London atlas (11.8 ± 2.9) years. The trends in this pilot study point towards more accuracy of London atlas over Demirjian's method when done using comprehensive chart for estimating DA. In summary, the results of the current pilot study indicates greater accuracy of London atlas method over Demirjian's comprehensive chart method for estimating DA in Indian population. This finding should be validated by conducting similar studies using larger sample, on diverse Indian ethnic populations, for applicability in pedodontic, orthodontic, and forensic domains.

Key points

No study has compared Demirjian's comprehensive chart and London atlas method in the Indian population.The dental age estimated by London method was closer to chronological age as compared to Demirjian's method in our study sample.Significant difference was found in chronological age and estimated age using London atlas method in both males and females.

The challenge of unidentified decedents in Africa: The need for training and research in forensic odontology to strengthen a multidisciplinary approach

Introduction

The management of unidentified decedents suspected to be undocumented migrants is a growing humanitarian crisis in Africa. Identification of the dead and the right of the family to know the fate of a decedent is a fundamental human right. Forensic odontology methods can provide helpful and assisting information in the identification even in challenging low-resource settings. South Africa and other countries that are part of significant migration routes face the problem of unidentified decedents.

Discussion

The fundamental application of forensic odontology relies on the availability of good antemortem dental records. The state of dental records was reported to be suboptimal in South Africa and other African countries. Incorporating forensic odontology into the undergraduate training in the 23 dental schools in Africa will increase the understanding of the value of maintaining accurate dental records and potentially facilitate collaboration with dentists and forensic odontologists in cases where dental features can be used for identification. South Africa offers postgraduate training in forensic odontology, and prospects for research in Africa need to be explored.

Conclusion

The development of a forensic odontology career path and research prospects will provide African countries with the potential for building multidisciplinary teams to assist in solving the challenge of unidentified decedents.

Dental maturation in a Chinese sample using Demirjian method

BACKGROUND

Dental calcification information is relevant for clinical, archaeological, and forensic applications. However, dental maturity measurements in current cohorts of Chinese children are insufficient.

AIM

This study aimed to establish the mandibular dental maturity table and determine the accuracy of dental age estimation using the Demirjian method in a Chinese sample.

SUBJECTS AND METHODS

Permanent mandibular teeth, excluding the third molar, in 2091 panoramic radiographs of 1008 males and 1083 females aged 3-15 were graded, and dental age was estimated according to Demirjian's criteria. Age-of-attainment was calculated with probit regression for each stage by sex, and sex differences were analysed using the Mann-Whitney U test. Dental age was compared with chronological age using paired t-tests.

RESULTS

Although females showed earlier age-of-attainment than males, significant sex differences were only found in stages D-G (p < 0.05). The Demirjian method overestimated the dental age in both males (0.68 ± 1.05 years) and females (0.59 ± 0.97 years).

CONCLUSIONS

The relationship between mineralisation stage and chronological age in this study can be applied as a reference for mandibular dental maturity of Chinese children and adolescents. The Demirjian method overestimated the chronological ages of this sample.

Validating dental age estimation in Kenyan black children and adolescents using the Willems method

PURPOSE

This study aimed to validate the Willems Belgian Caucasian (Willems BC) age estimation model in a Kenyan sample, to develop and validate a Kenyan-specific (Willems KB) age estimation model and to compare the age prediction performances of both models.

METHODS

Panoramic radiographs of 1038 (523 female, 515 male) Kenyan children without missing permanent teeth and without all permanent teeth fully developed (except third molars) were retrospectively selected. Tooth development of the seven lower-left permanent teeth was staged according to Demirjian et al. The Willems BC model, performed on a Belgian Caucasian sample and a constructed Kenyan-specific model (Willems KB) were validated on the Kenyan sample. Their age prediction performances were quantified and compared using the mean error (ME), mean absolute error (MAE) and root-mean-square error (RMSE).

RESULTS

The ME with Willems BC method equalled zero. Hence, there was no systematic under- or overestimation of the age. For males and females separately, the ME with Willems BC was significantly different from zero, but negligible in magnitude (-0.04 and 0.04, respectively). Willems KB was found not to outperform Willems BC, since the MAE and RMSE were comparable (0.98 vs 0.97 and 1.31 vs 1.29, respectively). Although Willems BC resulted in a higher percentage of subjects with predicted age within a one-year difference of the true age (63.3% vs 60.4%, p=0.018), this cannot be considered as clinically relevant.

CONCLUSION

There is no reason to use a country-specific (Willems KB) model in children from Kenya instead of the original Willems (BC) model.

Dental Age Estimation According to European Formula and Willems Method: Comparison Between Children With and Without Cleft Lip and Palate

OBJECTIVE

To assess dental age and deviations of dental from chronological age according to the Willems and Cameriere methods (European formula) in patients with cleft lip and/or cleft palate (CL/P) and compare it with control group.

DESIGN

Retrospective cross-sectional study.

SETTING

Clinic of Orthodontics.

PARTICIPANTS

Sixty-nine patients with CL/P between 6 and 15 years of age (55 with unilateral and 14 with bilateral CL/P) with 148 panoramic radiographs. The same number of radiographs was examined in the age-matched control group.

MAIN OUTCOME MEASURES

Estimation and comparison of dental age and differences of dental from chronological age in relation to the type of cleft, sex, and age in the group of patients with and without CL/P according to Willems and Cameriere method.

RESULTS

No significant intersex and intergroup differences were found in deviations of dental from chronological age according to Cameriere method (P > .05). Significant difference in deviation of dental from chronological age was found between the patients with and without CL/P according to Willems method (P < .001).

CONCLUSION

Cameriere European formula for dental age estimation, which is not influenced by sex and tooth morphology, showed similar dental development of children with and without CL/P. However, Willems method detected that deviation of dental from chronological age significantly differed between children with and without clefts.

The Broad Variability in Dental Age Observed among Childhood Survivors Is Cancer Specific

PURPOSE

The study aimed to assess the differences in dental maturation between childhood cancer survivors and healthy children.

Materials and Methods

Fifty-nine cancer patients including 16 (27.1%) girls and 43 (72.8%) boys, aged between 4 and 16 years, underwent dental and radiographic examinations. The mean duration of anticancer therapy was 16.8 months (range, 1 to 47 months), and 4.6 years (range, 8 to 123 months) had passed since the termination of disease. The control group consisted of 177 panoramic radiographs of age- and sex-matched healthy individuals. Dental age (DA) was estimated with Demirjian's scale and delta age, i.e., DA-chronological age (CA), was used to compare groups.

RESULTS

The DA of cancer survivors was accelerated by almost 1 year compared to their CA (9.9±3.1 vs. 8.9±2.8, p=0.040). The greatest difference was observed among patients with brain tumor: delta (DA-CA) was 2.2±1.1 years. Among all cancer patients, only children with familial adenomatous polyposis (FAP)-associated hepatoblastoma (HP) demonstrated delayed DA, with regard to both other cancer survivors (p=0.011) and healthy patients (p=0.037). All four patients with HP suffered from FAP, and three of them had documented adenomatous polyposis coli (APC) genes mutation. The DA of cancer patients having teeth with short roots was significantly greater than that of the cancer survivors without this anomaly (12.8±3.2 vs. 9.0±2.4, p < 0.001).

CONCLUSION

DA in children may be altered by cancer disease.