Impacts of the Number and Types of Teeth Employed in Assessing Development Ages From Skeletal Samples
SMC Affiliated Work
School of Science
American Journal of Physical Anthropology Supplement
Assessing developmental age is the first step in ontogenetic studies of skeletal remains. Many skeletal regions provide aging data, but for the fetal-young adult age range the dentition is the most accurate. Numerous studies provide methods for assessing developmental ages from teeth but vary in the number/types of teeth assessed and whether they include eruption data. We hypothesize that these varying methods have the potential to impact the range of variation exhibited in age groups and to create noncomparable samples.
To test this hypothesis we CT-scanned a dry skull sample (n=56). The dentition was evaluated via construction of isosurfaces and volume- texture renderings. Individual ages were calculated as averages of the degree of calcification per tooth; eruption was not assessed (range 4.7-9.1y). We then created age groups using various combinations of teeth and assessed changes in the statistical output for 93 cranial dimensions. We also examined the impact of these groupings on sample configuration in morphospace using Morphologika.
Age estimates varied between the upper and lower dentitions (-0.9-1.4y). Following studies that use only lower molars for aging resulted in a -0.6-0.8 year difference from the averaged age. Comparisons of a range of differentially aged groups to the original sample showed significant changes in the summary statistics for the dimensional series as well as substantial shifts between age groups in morphospace. These results demonstrate that caution should be exercised in compiling results from studies employing different aging methods or studies comparing individuals aged from partial dentitions to those aged with complete dentitions.
Jabbour, Rebecca: “Impacts of the Number and types of Teeth Employed in Assessing Development Ages from Skeletal Samples,” by Becker, Dana E., Castellon-Hinkle, Natasha A., Cirillo, Laura E, Burke, Elaine M., Ding, Julie, Jabbour, Rebecca S., and Gary D. Richards, American Journal of Physical Anthropology Supplement 156, S60 (March 2015), 81-82.
Becker, Dana E.; Castellon-Hinkle, Natasha A.; Cirillo, Laura E.; Burke, Elaine M.; Ding, Julie; Jabbour, Rebecca; and Richards, Gary D.. Impacts of the Number and Types of Teeth Employed in Assessing Development Ages From Skeletal Samples (2015). American Journal of Physical Anthropology Supplement. 156 (S60), 81-82. [abstract]. https://digitalcommons.stmarys-ca.edu/school-science-faculty-works/37