Our teeth have many essential functions. They help us bite and chew. They provide support for our jaw and our airway. They help us speak. And, of course, they provide an attractive display.
But these functions aren’t separate. As one of them changes, the others can be forced to change along with them, leading to wide-ranging changes in the way our teeth and jaws function.
That’s what some linguists are saying about teeth and jaw changes caused by agriculture. They say that these changes in response to different food sources may have also led to changes in our speech, a controversial assertion.
Writing in the journal Science, linguists argue that some important sounds we make today weren’t originally part of the range of sounds we could make when humans started speaking, perhaps 50,000 years ago. Instead, these sounds appeared relatively recently, perhaps 12,000 years ago when humans became farmers.
The changes occurred because people ate different foods (and ate them differently) once they became farmers. Agriculture and food processing technologies meant that people could eat softer food. In response, our jaws became smaller. In part because of the shrinking jaw and in part because of using utensils like a fork to eat, people developed an overbite.
The combination of small jaws and an overbite made it much easier for people to make sounds like f and v, which depend on being able to put your upper teeth on top of your lower lip.
This violates what is known as the uniformitarian principle in linguistics, which says that people have basically had the same ability to make speech sounds since they started speaking.
If people’s ability to make sounds has changed over time, it becomes much harder to study language use in the past. Much work in historical linguistics might be cast in doubt.
Of course, the change in sounds is not the only effect of changing jaw shape related to agriculture.
The shrinking of the lower jaw also led to less room for teeth, which has many consequences. First, it’s the reason why so many people need orthodontics. And it’s why many people need to have their wisdom teeth extracted these days. It also changed the shape of the airway, compressing it, which makes it more liable to collapse during sleep, what is known as obstructive sleep apnea.
In addition, changes to the jaw might also contribute to our risk of developing temporomandibular joint disorders (called TMJ or TMD). If the jaw joints evolved to sit in a particular relationship between the parts, while the teeth create a different relationship, it can put the joint in an unhealthy and uncomfortable position. It can also force the jaw muscles to mediate this tension, which can lead to tension in the muscles and/or force the muscles to grind down one or the other hard tissues–usually the teeth.
Unfortunately, we as modern people have to live with the consequences of the lifestyle changes of our ancestors. However, we have the tools to successfully deal with them–we can have healthy teeth and jaws despite these developmental challenges.
If your teeth are crooked or crowded, orthodontics like traditional braces or Invisalign can help. And if you’re experiencing TMJ or other bite problems, we can help restore your jaws to healthy function. In addition, we can restore teeth that have been damaged or worn by these bite problems.
To learn more about how we can help restore health, beauty, and function to your jaw, please call (509) 532-1111 today for an appointment with a Spokane neuromuscular dentist at Collins Dentistry & Aesthetics.