Dead Tooth Theory 

In a competition, there are two clear favorites and then some other garbage. One of the favorites has to take a loss. When this happens, the other competitors cannot be moved ahead of the loser simply because of the loss. See example for correct application of said theory.

Per Colin Cowherd:
I would still rank Alabama and LSU 1 and 2 after this weekend if the game is close. Just because one of these teams has to take a loss doesn’t mean that the other undefeated teams out there are suddenly better. It’s like a beauty contest where there are two clear favorites and another girl has a dead tooth. The results are announced and one hot girl edges the other. Does that mean that you drop the loser below the girl with the DEAD TOOTH?!?!?! NO!!! And Oklahoma State, Boise State, and Oregon all have a dead tooth. It’s the Dead Tooth Theory.

Dead Tooth Theory by THE_HERD November 4, 2011

snaggel tooth 

A fucked up tooth that is out of place, generally sticking out of the gums above other teeth. Someone who probably shouldn't smile.

Look at her snaggel tooth, it's so fucking gross!

snaggel tooth by Bellaf0fella March 19, 2016

Shiny tooth nigga 

Any rapper who is stupid enough to gold plate their teeth.

Look at that shiny tooth nigga slingin over there.

Shiny tooth nigga by Mr. Mundee May 3, 2021

Trucker's Tooth 

A male version of a camel toe. When a guys pants are so tight that his balls straddle the seam.

His pants are so tight he has a Trucker's Tooth.

Trucker's Tooth by lelsie September 25, 2011

Have a spicy tooth 

Idiom

If you have a spicy tooth, you like eating spicy foods.

This restaurant is great for those who have a spicy tooth.

Have a spicy tooth by Zami Karzai September 12, 2018

Nothing grows on a dry tooth 

Nothing grows on a dry tooth is an old Canadian idiom. It means that being bitter and closed off can't lead to any change/making new friends. Saying it is a good way to call out your friends out when they display un-Canadian-like behaviour.

Can I have a bite of your pancake?
No.
Nothing grows on a dry tooth.

Nothing grows on a dry tooth by Gotzzz July 31, 2016

Scraggle-Tooth 

A person whose teeth are so out of control and f'ed up that they look like a backwater hick.

Jewel is a scraggle-tooth.

Scraggle-Tooth by Jake the King July 30, 2003