ZMT: Daily Fact: Your skull never stops growing

Daily Fact: Your skull never stops growing

Original photo by Svet foto/ Shutterstock

The human skull never fully stops growing.

By the time most of us reach age 20 or so, the bones in our body are pretty much done growing. The growth plates that cause us to put on inches in our youth are now hardened bone, and in fact, adults tend to drop an inch or two in height as worn-out cartilage causes our spines to shrink over time. However, there are a few bones that buck this biological trend. Skulls, for example, never fully stop growing, and the bones also shift as we age. A 2008 study from Duke University determined that as we grow older, the forehead moves forward, while cheek bones tend to move backward. As the skull tilts forward, overlying skin droops and sags.

The skull isn't the only bone that has a positive correlation with age. Human hips also continue to widen as the decades pass, meaning those extra inches aren't only due to a loss of youthful metabolism. In 2011, researchers from the University of North Carolina School of Medicine discovered that hips continue to grow well into our 70s, and found that an average 79-year-old's pelvic width was 1 inch wider than an average 20-year-old's. So while it's mostly true that humans stop growing after the age of 20, nature always likes to throw in a few exceptions to the rule.

Numbers Don't Lie

Number of bones in an adult human skull, including 8 cranial bones and 14 facial bones

Max amount of time (in months) it takes for the anterior fontanelle in a baby's skull to close

Year the band Grateful Dead created their famous blue-and-red skull logo

1969

Estimated number of skulls discovered in 2001 at the now-famous Brno Ossuary in Czechia

50,000

The idea that your ears and nose never stop growing is a myth.

It's a common misconception that our ears and noses continue to grow throughout our lifetime — though they sometimes do appear to take on almost cartoonish proportions toward the end of our lives. So what's going on here? Turns out, it's not really the cartilage in our nose and ears that's to blame. Instead, the culprit is decades of experiencing gravity. This constant gravitational pull — along with general degradation due to age — causes the collagen and elastic fibers in our ears and nose to droop and elongate. The surrounding skin supporting these structures also breaks down and droops over time while simultaneously losing volume. Studies have shown that the average human ear elongates approximately 0.22 millimeters a year. It's a process that's so reliable, ears can actually be used as a tool for determining a person's age.

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Daily Fact: Your skull never stops growing