Socioeconomic differences in tooth calcification and age estimation of immature skeletal remains in forensic practice

1. Socioeconomic differences in tooth calcification and age estimation of immature skeletal remains in forensic practice Hugo F.V. Cardoso Departamento de Antropologia, Universidade de Coimbra, Portugal Department of Anthropology, McMaster University, Canada hcardoso@antrop.uc.pt

2. SES and tooth calcification • There is some debate as to the impact of SES factors on dental development • The vast majority of aging standards in use today have their origins in growth studies of well-nourished, well-cared-for children from either North America or Western Europe. • These studies represent optimal rather than average or modal growth rates.

3. SES and tooth calcification • No studies of socioeconomic differences in tooth calcification (except Cardoso, 2005; Heuzé et al., 2005) • Studies of SES and tooth emergence (scarce; 0.23/0.27 year delay in low SES) • Secular trends and tooth calcification (advancement/no signif. differences)

4. SES and tooth calcification • Lisbon collection provided the unique opportunity as a test case for the examination of socioeconomic differences in the rate of tooth calcification • Lisbon Collection: • > 1800 identified skeletons • Mostly individuals of Portuguese nationality living in Lisbon • Births and deaths between late XIX and late XX century • > 700 skeletons with available documentation (Sex, age at death, place and cause of death, place of birth, occupation, address at the time of death and marital status) • 117 subadult skeletons (< 20 years old)

5. SES and tooth calcification • Due to preservation, completeness of documentary information and methodology, sample size was reduced to 59 individuals: • Age ranges from 3 months to 12 years of age • Years of birth between 1911-1971 and years of death between 1917-1973 • Most lived in Lisbon at time of death • Additional documentary information: • Date of birth • Illegitimacy of birth • Father’s occupation • Place of residence

6. SES and tooth calcification • Dental age was calculated using a modification of the Moorrees, Fanning & Hunt’s (1963) standard • Discrepancies between chronological and dental age were calculated (relative measure of delay/advance in toot calcification) • Discrepancies were compared in two sub-samples of different socioeconomic status (SES)

7. SES and tooth calcification • Individuals in the sample were classified into high and low socioeconomic status, according to: • Occupation of the father (manual versus non-manual) • Place of residence (socioeconomic condition of the place of residence; demographic indicators utilized to develop a socioeconomic scheme of all administrative sub-divisions – freguesias - of the city of Lisbon)

8. SES and tooth calcification • Assumptions: • Same sample (within population comparison) • The dental age method is irrelevant • Genetic differences are irrelevant • The socioeconomic gradient observed in this “past” sample represents an equivalente gradient as in any “modern” sample

9. SES and tooth calcification • Occupation of the father t = 1.76 p = 0.0848

10. SES and tooth calcification • Place of residence (freguesia) t = 1.85 p = 0.0705

11. SES and tooth calcification • Eleven (n=11, 5♂ and 6♀) individuals that showed the largest discrepancy between chronological and dental age: • Five were illegitimate children • Eight were born in rural areas or poor areas in Lisbon • In ten the father had a low or very low occupational class (e.g. Knife sharpener or Roadmender) • Six lived in poor areas of the city of Lisbon • The only two individuals of apparent higher SES died of illnesses that suggest chronic conditions of ill-health (Rheumatic endocarditis and tuberculous adenopathy) • Births earlier in the 20th century

12. SES and tooth calcification Three examples: • Collection # 385 (♂) • Chronological age = 7.42 year-old • Dental age = 6.51 year-old • Born in a poor area (Bairro do Caramão) and lived nearby. Illegitimate child • Collection #574 (♂) • Chronological age = 9.75 year-old • Dental age = 8.21 year-old • Born in Covilhã and lived in a shed in a Lisbon slum (Arco do Carvalhão). Father was a knife-sharpener

13. SES and tooth calcification • Collection # 600-A (♂) • Chronological age = 3.50 years-old • Dental age = 1.95 years-old • Born and lived in Madragoa (poor port neighbourhood). Father was a sailor. Born in 1913

14. SES and tooth calcification • Conclusions: • At the population level, tooth calcification does not show significant or only minor differences between socioeconomic groups; • However, from an individual perspective, caution should be given to the fact that at the lower extreme of the socioeconomic gradient, significant underestimates of dental age may occur

15. Acknowledgments Attendance at this meeting was funded by: Centro de Investigação em Antropologia Coimbra, Portugal