Saturday 17 June 2017

How many bones does a sixteen-year-old have?

This question is a tricky one for a couple of reasons. First, the number of bones in the body changes during our lifetime. Newborn babies have around three hundred bones, but throughout childhood, adolescence, and even into adulthood, many of these bones will fuse together. Have you ever looked at an adult skull and noticed the lines running across the top and back of the skull? These are the seams where five cranial plates have...

This question is a tricky one for a couple of reasons. First, the number of bones in the body changes during our lifetime. Newborn babies have around three hundred bones, but throughout childhood, adolescence, and even into adulthood, many of these bones will fuse together. Have you ever looked at an adult skull and noticed the lines running across the top and back of the skull? These are the seams where five cranial plates have grown together. In a newborn, these five plates of bone were not connected, but during growth they have fused into one piece of cranial bone. 


Everyone experiences growth at a slightly different rate; as such, two people of the same age may have slightly different skeletal structures. Biological sex plays a part in when bones are fusing, with female adolescents completing their bone growth and fusion a few years earlier than males. For example, the growth plates of the elbow fuse at about age twelve to fourteen in females, but not until fifteen or sixteen in males.


That being said, almost all people complete their skeletal growth and fusion by the age of twenty-one, and the majority of people are finished by age eighteen. Much of the fusion which reduces the bone count (as with the cranial plates) takes place in childhood or early adolescence. With this in mind, I would estimate a typical sixteen-year-old has slightly more than or about the same number of bones as an adult: two hundred and six.

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