Biology Reference
In-Depth Information
TABLE 3.1 Common Age-at-Death Estimation Techniques
Indicator
Reference
JUVENILES
Formation of Ossification Centers
Scheuer and Black, 2000
Epiphyseal Union
Scheuer and Black, 2000
Long Bone Length
Schaefer et al., 2009
Dental Development
See Hammerl (Chapter 10), this volume
ADULTS
Pubic Symphysis
Brooks and Suchey, 1990
Auricular Surface
Lovejoy et al., 1985b
I¸can et al., 1984a,b
Fourth Rib
First Rib
DiGangi et al., 2009
Cranial Sutures
Meindl and Lovejoy, 1985; Nawrocki, 1998
Medial Clavicle (Older Adolescents, Young Adults)
Langley-Shirley and Jantz, 2010
Sacrum
Passalacqua, 2009
Dental Wear
Brothwell, 1989
Histology
Crowder and Pfeiffer, 2010
Multifactorial Method
Uhl et al., 2011
unique to humans compared to other species (
Smith and Tompkins, 1995
), is fairly predict-
able among human infants. Given this predictability we can utilize long bone length, dental
development, or timing of epiphyseal appearance and union to estimate age-at-death for
subadult remains, although the timing and extent of growth are known to vary, sometimes
significantly, based on ancestral population and biological sex, and this variation increases
with age (
Stewart, 1979; Krogman and I¸can, 1986; Ubelaker, 1987; Humphrey, 1998
).
Bone and Tooth Maturation and Growth
Formation of Ossification Centers
Human bone forms by two primary mechanisms
d
intramembranous ossification and
endochondral ossification. Intramembranous ossification primarily occurs in the bones of
the cranium, the facial bones, and the clavicle. The clavicle is the first bone in the body to
begin ossification, commencing around 6 weeks' gestation, and the final bone to finish ossi-
fication in the late twenties (
Scheuer and Black, 2000
). Intramembranous ossification involves
the direct mineralization of a membrane of mesenchyme (embryonic connective tissue) in
a flat, spherical shape. The final product of intramembranous ossification is a layer of dipl ¨e
(spongy bone) in between two flat layers of compact bone, as in the parietal bone.
