Where does the phrase "No skin off my teeth/nose" come from?

The phrase "it's no skin off my nose/teeth" is generally used to mean that something isn't much of a risk/concern. But where does it come from? Specifically with respect to teeth. What is tooth skin?

Solution 1:

"No skin off my teeth" is not an expression in the UK. Apparently it does exist in the US where it means "no skin off my nose".

Saying "X is no skin off my nose" means that X occurring won't affect you in a positive or negative manner, the outcome will be neutral to you. The phrase is explained by phrase finder as being of boxing origin. I assume because boxers' noses are the body part most prone to damage.

As James McLeod points out "skin of my teeth" means only just or barely. This question addresses its origin.

Solution 2:

This Ngram suggests no skin off my nose is more common and originated around 1930, and no skin off my teeth around 1940.

Modern proverbs and proverbial sayings from 1989 gives the following:

1929 WFaulkner Sound (NY) 307: It was no skin off my back. 1932 MTurnbull Return (P) 90: 'Tain't no skin off my nose. 1933 WMarch Company K (NY) 141: It's no skin off my back-side. ...

1952 HWaugh Last Seen (NY) 87: It's no skin off my teeth whether she's alive in Michigan City or dead in Boston. 1954 HStone Man Who (NY 1957) 15: Fatso was no skin off his nose. ...

Cambridge Idioms Dictionary, 2nd ed. gives geographical usage:

It's no skin off my nose. (British, American & Australian informal) also It's no skin off my (back) teeth. (American informal)
something that you say which means you do not care about something because it will not affect you We can go in his car if he prefers. It's no skin off my nose.

No skin off my nose

The earliest "no skin off my nose" I found in Google Books is from a 1910 The Cosmopolitan: Volume 49:

And a 1910 The Saturday Evening Post: Volume 183, Issue 2:

“Of course, Max," Abe added, using his partner's metaphor, “it ain't no skin off my nose, y'understand." “Ain't it?" Max growled as he turned on Abe with a menacing glare. “Well, it's a wonder it ain't, the way you are sticking it into ...

Earlier than this, losing the skin off your nose would happen after a long, tough journey in the sun, or from the intense frost of a cold journey.

No skin off my teeth

Answers to another question here at EL&U suggest the -teeth phrase is a combination of
by the skin of one's teeth and it's no skin off my nose, as this and this. The -teeth phrase seems to have originated in the southern US. This is a mixed metaphor, and yet another variation of "no skin off my nose/back/backside".

The earliest "no skin off my teeth" I found in Google Books is from a 1938 The Atlantic monthly: Volume 162:

Cap'm,' he said, looking at the ground, 'I'ma man don't never kick in no other man's stall.' 'Well, maybe you do and maybe you don't. That ain't no skin off my teeth, and if you get killed messin' around here that won't be nothin' new. Anyhow, it ain't gonna be to-night. You been givin' me the creeps with them songs you been singin'. Now let's hear somethin' lively.

Solution 3:

I'm from the American South, where "no skin off my teeth" is a common phrase. It may be a mixed metaphor, as others have stated; however, it makes sense in that your teeth have no skin and therefore "losing" this nonexistent skin would have no consequence--as in, you can't lose what you don't have. At least that's how I always reasoned it when I would hear the phrase as a youngster.

Looked at in that way, it actually makes more sense than "no skin off my nose." Many Southern Americans have pure British lineage. Perhaps the modern usage in Britain is the mixed metaphor, and the Southern American usage is the same as it was passed down from Colonial Americans? This is all just conjecture on my part. But think about it. It makes sense.