What is the evolutionary purpose for people to have crooked teeth?

Question

I know many people get braces, sometimes to prevent infections and eating/heath difficulties.
And the wisdom tooth is commonly removed because it does not grow straight and may cause damange to the other teeth.

Why have humans evolved to have some people crooked teeth and other teeth alignment problems? (while some people have naturally straight teeth?)
What is it's purpose, if any?

Answer 1

My dad was from an era when there was almost no intermarriage among different ethnicities. Even "white" people tended to marry those of similar background. In other words, a Brit would not marry a German or a Russian would not marry someone from France. Heck, most people wouldn't even marry someone from a different region of their own country. This made for a fairly homogenous gene pool and most people looked quite a bit alike. This is the reason we can look at someone and say, "He looks kind of Italian," and so on. There was a limited variation of features.

Once people - especially in the good old U. S. of A. - got to know each other and found that people from other regions of the world were not from the planet Mars, they started to intermarry; much to the dismay of the prior generation in most cases. When these marriages started to produce offspring, you could see that the baby got his eyes from Dad and his hair color from Mom, and so on. Well, it was only natural that, in some cases, the child might get Dad's huge teeth and Mom's tiny bone structure. My wife's teeth look exactly like her father's flat, square teeth and her brother's teeth look exactly like his mother's small and rounded teeth. Instead of getting teeth that fit nicely in the jaws, we started to see a jumbled up mess. I'm not saying that man never had crooked teeth prior to the 20th century, but it was my father's observation that far, far more people had crooked teeth when their parents were of differing ethnic backgrounds. The span of his career was from 1936 (dental school) to 1992, so he saw a lot in that time. I do believe that he was correct in assessing the social changes in America (and probably other countries) and the role it played in the growth of the specialty of orthodontics.

And don't forget (just as a sidebar) that having your teeth straightened by braces does not mean your children will be born with straight teeth.

There may be an evolutionary trend towards lower incidence of third molars in humans, but this kind of thing occurs over a period of thousands and thousands of years. I think we have seen an explosion of people with crooked teeth in just fifty years. There is no evolutionary purpose for having crooked teeth. Heck, if we were still living in caves and had no orthodontists, maybe the people with crooked teeth and crossbites would die off because they couldn't chew as well as their orthodontically correct brethren.

Answer 2

I have quite a small mouth and had crooked teeth and teeth growing up and down from everywhere all over the place, the dentist were quite amazed and had to study my teeth for a week before he could try anything on my mouth. I often asked myself why do I have such naughty teeth and my friends such beautiful natural straight teeth. It baffled my mind for long, but I've made peace with that, nobody knows why anyway.

Answer 3

I'm a dentist.

We didn't evolve to have crooked teeth. Crooked teeth is basically a disease (like a deviated septum) that most people survive with no problem. Hence, there is no evolutionary selection pressure to eliminate these issues--especially with the existence of orthodontic therapy.

Make no mistake about it, though, we are not "supposed" to have crooked teeth.

Answer 4

Crooked teeth.. A guys smile is one of the first things I look at.. I mean.. not that a guy could have saggy breasts lol

Answer 5

Back in the days of cave dwelling Im sure that everyones teeth were nice and staright because of all the exercise they got chewing meat. We eat very lazily now and the teeth can just go wonky and there is no natural way to correct it. Anyway, it keeps the dentists in work lol;

Answer 6

Diversity in the gene pool allows for adaptation to unforseen environmental change.

Life is a messy thing.

Answer 7

So that dentists can have plenty work to do. What would they do if they have no work to do? Become extinct?