Genes and Multiple Rows of Teeth

[mummblingme]

A recent Skeptoid episode discussed "aliens" with multiple rows of teeth. Although Brian Dunning found no hard evidence of any skulls with multiple rows, the occurrence could have occurred in people caused by the turning off of a single gene, and so be just a genetic fluke if it does happen:

Web site: newsmanager.commpartners.com/aadr/issues/2009-03-12/9.html

[caulkins]

I went to high school with a kid who had an extra set of upper incisors behind the normal ones, so it does happen.

[tyr_13]

I have an extra set of wisdom teeth on the top and bottom and both sides. There is also enough room in there for all the teeth. This is apparently fairly odd. I hope to confuse an archeologist someday.

[briandunning]

This was very interesting, because I heard from an anthropologist after the episode aired. According to him, the Hopewell culture routinely made jewelry out of the jaws of their enemies, into which they bored holes and inserted an extra row of teeth. This jewelry is more than likely what prompted the stories of double-toothed races.

The Hopewell and other cultures also disarticulated the bodies of their enemies and buried them, thus creating a skeleton that was 7 or more feet long. He sent me pictures of this. Very interesting.

Much more interesting than my finding, which was that most of these stories were simply made up. Truth is always stranger than fiction, so they say... :-)

[Blackadder]

I had 6 upper incisors as well, both baby teeth and adult teeth. The first set just dropped out naturally. But the adult extra 2 teeth had to be surgically removed, because they grew in the wrong direction. It took 2-3 years in high school to fix the whole thing, but in the end you didn't see any difference from normal.

However it makes you appreciate modern science. My smile would not be very nice in medieval times.

[Trevor]

I went to high school with a kid who had an extra set of upper incisors behind the normal ones, so it does happen.

I was going to say the same thing. I knew a kid in elementary school with an extra row of upper teeth. It was very weird looking, but not noticable unless you looked for it.

[pokemom]

I know this is an old thread I'm posting to, but I've been trying to find out just how common (or uncommon) an extra row of teeth actually is.

We never thought much about it (on an individual basis) and never mentioned it to each other. That all changed at a recent family gathering when one of my four daughters showed us her extra teeth. She has nearly a full extra row on the bottom and nobs behind her upper teeth indicating they are there as well. That's when the rest of us showed our extra teeth. Some had just a couple behind their uppers, some just a few behind their lowers, but all of us had extra teeth. This is not a case of baby teeth that never fell out, these are two rows of adult teeth! (I know, I was there for every lost baby tooth.) The second row did not start pushing through until the late teens/early twenties.

Any insight on this would be appreciated. (And no, we are not giants!)

[fuelair]

Can't help with this, but welcome to the forum pokemom!!!

[Pulvinar]

I know this is an old thread I'm posting to, but I've been trying to find out just how common (or uncommon) an extra row of teeth actually is.

Here's one report that says supernumerary teeth were seen in 2% of the subjects (table 2):
http://jdr.sagepub.com/content/75/10/1742.full.pdf

[Pulvinar]

Another source:
http://www.jcdr.net/articles/PDF/1290/1877.pdf
"The aetiology of hyperdontia is still uncertain. A hereditary component has been suggested [5-7] and current genetic studies have revealed the possible intervention of ectodine as an inhibitor protein against the third dentition [8-10]. The incidence of supernumerary teeth varies between 0.45-3%, depending on the literature source and is more common in females than in males (proportion 2:1) [11], [12]."

[pokemom]

Thanks! That's exactly what I was looking for.