Age Determination From the Skeleton
Todd
1920 develops first aging system morphology of pubic symphysis four parts of symphysis four features -billowing -ridging -ossific nodules -texture 10 phases
Suchey-Brooks system
1984 reduced Todd's phases from 10 to 6 revised system based on LA coroner sample (modern and multi-ethnic_ standards for males and females
Iscan and Loth
1984-1986 sternal ends of ribs pattern of changes observed pits forming, edges jagged, irregular rim
Lovejoy and colleagues
1985 alternative to pubic symphyses= auricular surface of Ilium more often preserved than pubic symphyses changes continue past 50 years porosities: small and large retroauricular activity
general approaches to adult age estimation
macroscopic vs. microscopic techniques single vs. multifactorial methods
tooth root transparency
Lamendin et al. 1992
accuracy depends on
age categories (subadult aging more precise) skeletal elements available (some bones more informative than others) aging method used (some methods better than others)
fetal and infant material
bone size useful for predicting age at death
standards for age determination
clinical studies of living individuals -childhood growth -dental development -radiography of wrist known age skeletal collections
dental aging methods
comparison with a developmental chart scoring of individual teeth 14 stages
bone remodeling and age
count number of osteons and osteon fragments, % of lamellar bone remaining, then plug into regression equation to predict age not more accurate than macroscopic techniques
notes on dental aging standards
dental chart ages are male/female averages girls develop faster precision of age estimate drops with age +/- 2 months to +/- 3 years average error ranges but individuals may vary further
what is the most precise aging method?
dental development; under strong genetic control
three methods for estimating age at death in subadult remains
development and eruption of teeth long bone length appearance and union of epiphyses
appearance and union of secondary growth centers
epiphyses most useful ages between 10-20 years separate epiphyses easy to see on dry bone
microscopic age determination
first attempt: Kerley 1965, using ground bone sections from femoral shaft later modifications by Kerley and Ubelacher (1978) advantages: can be done on bone fragments, age estimates into the 60s disadvantages: destructive, time-consuming, requires special equipment
general issues in estimating age at death
how accurately can one determine age at death from skeletal remains? how were these standards developed, and from what population sample? can standards developed from one population be applied to another?
tooth wear
of little use in forensic anthro; we don't wear our teeth down
cranial suture closure
one of the earliest developed (19th century) sutures gradually obliterate during adult life general correlation with age ut nots of variability
degenerative skeletal changes
osteoarthritis tendon and ligament attachments ossification of cartilage
long bone length
second choice for estimation when teeth are missing long bones measured without epiphyses not as precise as dental age individual variation, sex differences in growth timing
general observation son epiphyseal union
several years normally elapse between partial and complete union sex differences in timing (girls 1-2 years ahead of boys in epiphyseal development and fusion) in both sexes there is variation of 2-6 years between individuals
multifactorial aging
standard approach skeletons often incomplete so one method won't work for all multifactorial methods allow one to avoid trap of "anomalous" skeletal feature
age distribution and variation within phases
tight distribution in early phases allover the place in later phases