According to a study, the late emergence of our wisdom teeth is due to the morphology of our skull and its very slow growth.
On the scale of the animal kingdom, our wisdom teeth are a curiosity. Unlike other animals, including primates, mankind is the only one that has to wait that long before having a complete dentition. An observation that left science perplexed for a long time, until very recently. Researchers from the University of Arizona have just unveiled a study spotted by Science Alert which seems to answer this question.
It has been several years since science noticed a link between the emergence of wisdom teeth and the morphology of the jaw. “One of the mysteries of human development is the precise synchronization between the emergence of molars and the history of the individual.”, Explains Halszka Glowacka, lead author of the study.
Dozens of high-tech models
The researchers therefore sought to find out what precise factors were at play. To do this, they created 3D reproductions of human skulls. But these are not simple anatomical reproductions. They produced extremely complex biomechanical models; In addition to the skeleton, these skulls also included reproductions of the tendons and muscles associated with chewing.
They have done this work for around 25 species of primates, from lemurs to gorillas to humans. And each time, they made a model for each major development milestone. A titanic work, which allowed them to obtain a whole collection of functional skulls. It was by putting these skulls to the test that they were finally able to obtain concrete answers.
Growth time and jaw shape play a major role
Their models revealed that there is a very clear relationship between the emergence of wisdom teeth and the growth of the face. More precisely, the growth time, the jaw shape and the distribution of chewing muscles would play a key role. The slower the growth, and the less the jaw is elongated and protruding, the less space the wisdom teeth have and come out late.
“It turns out that our jaws grow very slowly compared to other primates.”, Explains Gary Schwartz, specialist in biomechanics. “In combination with our relatively short faces, this delays when the molars have a “safe space”, with enough room to emerge without doing damage.”
Leads in clinical dentistry
Now that this link has been established, it offers new avenues for research. They now hope to create models of fossilized human skulls; an experience that may allow them to learn more about the evolutionary path that separated our ancestors from other primates.
And according to the researchers, this work could even end up being useful to your dentist. For example, we can imagine statistical models which would allow preview where, when and how these teeth will emerge according to the morphology of the face. In some patients, this could help identify the problem upstream, before it causes complications.