One tooth is way smaller than the others—what's the cause?

I have one tooth that is roughly half—maybe even three-quarters—smaller than all my other teeth. It’s been this way for several years now; there was no injury involved, nor has there ever been any pain. I simply looked in the mirror one day and noticed just how much smaller it appeared compared to its neighbor. As for the shape of the biting surface, it looks perfectly normal to me—nothing suggests significant wear or erosion.

Does anyone happen to know how this could have happened or what the underlying cause might be?

I've attached some photos below. I wrote the description in English because I actually posted this same question on an American forum recently, though I didn't receive a single helpful response. My apologies if the photos are subpar; it's surprisingly difficult to get a clear shot that stays in focus while also capturing the right angle to demonstrate this size discrepancy.

I haven't the slightest clue, really—but if I were in your shoes, I would certainly head over to the dentist for a professional cleaning and some expert advice. Those little pits you're describing on your molars? They look quite a bit like erosion to me.

coppergardener said:I’m no expert, obviously, but I would definitely head to the dentist for a professional cleaning and some actual advice—those little pits on your molars look suspiciously like erosion to me.

Are you suggesting we're looking at erosion caused by stomach acid reflux?

David Flores68 said:Do you think it could be erosion caused by acid reflux?

Well, yes—but it isn't necessarily just that, is it? It could certainly stem from frequent vomiting, or perhaps a poor diet—say, consuming far too many sugary sodas—and honestly, who knows what other factors might be at play here? There are so many variables to consider!