Benefits and limitations of dry bone studies
> only a snapshot in the ageing process; cross-sectional not longitudinal.
often based on archaeological collections in which age may be estimated.
Very limited population sample; from one niche; does not encompass human variation
Benefits and limitations of imaging studies
> can be longitudinal or cross-sectional
images taken from medical records due to ethics; cannot be performed for aging research.
Can be used for estimation in both living and dead individuals.
extensive ethical considerations.
where CT is used, slice thickness in living individuals may cause images to be poor quality.
Major sources of error in age estimation
> The inherent variation of the process of ageing across individuals and populations; lifestyle dependent.
Dependent on the investigator’s skill in producing the estimate.
Suchey-Brooks method
- A modification of Todd; compressed into 6 phases.
- Appearance of pubic symphysis: presence of billowing, defined ridges and furrows; ventral and dorsal borders + lipping; Tubercle on superior surface; general texture.
3.Produced casts with 2 in each phase showing variation range. - Limitations: age ranges are large with great overlap; Requires intact pubic symphysis = pubis is fragile but more likely to survive than ribs etc.; Shown to be more accurate for younger individuals, decreases with age with older individuals age being underestimated.
- In validation studies; has been found to correctly age less than 70% of individuals.
- Based on a large multiracial sample of diverse socio-economic backgrounds = modern/20th century (from LA autopsies)
Lovejoy Auricular surface method
- 8-phase scheme for all racial groups and both sexes.
- Based on Libben and Hamman-Todd Collections; >75% of the sample was of unknown age, sex, and race.
- Observed: transverse organisation, retroauricular activity, apical activity, texture, porosity.
- Auricular surface for ageing not as thoroughly tested as pubic symphysis.
- Survives well due to positioning but more difficult to apply.
- Method found to underestimate age at death, especially in older individuals.
- High inter and intra-observer error found suggesting difficulties with applying the method.
Buckberry and Chamberlain Method
- Revised the Lovejoy method applying a new scoring system based on archaeological material and tested on the Spitalfields collection.
- Scored; surface texture, micro/macro porosity, apical activity.
- Tested and found to be easier to apply than Lovejoy; less accuracy for younger individuals but improved with age.
- Overall, auricular method shows reduced accuracy and is recommended to only be used in conjunction with other ageing methods.
Limitations of using imaging to age the clavicle
- Studies examine the ossification/fusion of the sternal epiphysis.
- X-rays = Schemling: 5 stages of ossification. Many structures overlayed introduces interference; can make determining the stage difficult.
- CT = Kellinghaus: applied Schemling to CT: CT slices remove interference; unknown if same scoring can be applied to both imaging methods.
- Found that socioeconomic status does influence ossification timing; may result in age underestimation.
Iscan rib method
- Developed using individuals from routine PM exams; known age; modern sample.
- 9 phases of evaluation; ranges and images vary for males and females; differing morphological patterns of ageing.
- Observed: pit depth, shape, configuration of walls and rim surrounding the pit; texture and quality of bone.
- Testing revealed minimal interobserver error.
- Method tested and applied to other ribs; no differences between left and right; when 4th rib is unavailable all ribs should be reviewed and a composite score produced.
Cartilage ossification for age estimation
- Both laryngeal and hyoid fusion found to be very variable = only useful in estimating broad age categories = of limited forensic use.
- McCormick and Stewart; Plastron = articulated skeleton; radiographs; found to be incredibly accurate in sex determination; 95% of individuals aged within 25% of actual age.
Meindel and Lovejoy suture method
- Background: cranial suture examination should only be used as a last resort in ageing, many studies state it is either only suggestive of age or unreliable; inter-racial differences have been observed.
2 Method: Ectocranial suture closure developed on Hamman-Todd collection. lateral-anterior and cranial vault suture systems. 1-4 ranking of suture closure from open>obliterated. Scores are summed and composite score correlates to mean age. - Testing: found to show strong sexual dimorphism, more useful in females. low correlation with age overall.
- Further studies of suture closure found it to be unlinked to age; genetically inherited.
Arachnoid granulations method
- Barber: correlation found between granulation number and age; tested on other populations, correlation still present but suggested population-specificity.
- Duray and Martel: Arachnoid fovea volume using sand. Found no relationship between volume/number and age. Suggested it is instead caused by health factors. Tested on Hamman-Todd collection = potential ill health may have produced sample bias.
