Skeletal Secrets: Determining Age

Image from ScienceDirect.com

Ever wondered how forensic scientists figure out how old someone was just by examining their bones? It’s like something out of a mystery novel, but in the world of forensic anthropology, it’s a common—and fascinating--practice. This is the first in a series of blogs looking at what you can (and can’t!) tell from a skeleton.

Growing Pains: Childhood and Adolescence
When we're young, our bones are like puzzle pieces that haven’t quite fit together yet. Forensic anthropologists start their age estimation by examining features that change as we grow.

• Dental Development: Teeth are incredibly telling. Kids get their baby teeth first, followed by their permanent teeth. By looking at which teeth have come in and their stage of development, experts can estimate the age of children and teenagers quite accurately.
• Bone Growth Plates: In younger individuals, the ends of long bones, like those in the arms and legs, have areas called epiphyseal plates. These plates gradually turn into solid bone as a person matures. By assessing how these plates are fusing, scientists can estimate the age, especially for teens and young adults.

By Gilo1969 at English Wikipedia, CC BY 3.0, https://commons.wikimedia.org/w/index.php?curid=21568585

The Adult Years
As we move into adulthood, the changes in our bones become subtler but still informative. Here’s how forensic anthropologists discern age in adults:

• Pubic Symphysis: One of the best clues comes from the pubic symphysis, where the two halves of the pelvis meet. Over time, this joint undergoes changes in texture and shape. Forensic experts examine these changes to estimate age within a certain range.
• Cranial Sutures: The skull is made up of several plates that are joined by sutures. In younger people, these sutures are more open and flexible. As we age, these sutures slowly fuse together. By examining how much these sutures have fused, experts can make an educated guess about an individual’s age.
• Sternal Rib Ends: The ends of the ribs where they attach to the sternum (breastbone) also provide valuable age clues. As people age, these rib ends undergo specific changes. They start out smooth and flat, but over time, they become more irregular and pitted. By studying these changes in the rib ends, forensic anthropologists can estimate age, especially in middle-aged to older adults.
  
  

The Golden Years
In older adults, bones undergo significant changes that forensic anthropologists can use to estimate age:

• Degenerative Changes: As we age, our bones show signs of wear and tear. This includes arthritis or changes in the surface texture of bones. By analyzing these degenerative changes, experts can provide clues about an individual's age.
• Bone Density Loss: Older adults experience notable bone density loss, which can be visible in bone examinations. This loss, along with other aging markers, helps in narrowing down the age range.
  
  

How They Get It Done
Forensic anthropologists use a combination of visual inspection, measurement, and sometimes advanced imaging techniques:

• Microscopy: For a very detailed examination, they might use microscopes to look at bone surfaces closely.
• CT Scans and X-rays: These imaging techniques can reveal internal structures and changes in bone density not visible to the naked eye.
• Statistical Methods: Forensic scientists often use statistical models to compare their findings with known data, improving the accuracy of their age estimations.
  
  

Determining age from skeletal remains is a blend of science and art. Forensic anthropologists meticulously examine bones, looking for clues that reveal how an individual aged over their lifetime. From the development of teeth in children to the subtle signs of wear and tear in older adults, each part of the skeleton holds a piece of the puzzle. So, the next time you hear about a forensic anthropologist solving a case, remember—it's not just about solving crimes but also about piecing together the life story of someone through the intricate details of their bones.