haha, I'm just teasing you...those were too good to pass up
So, if we're going with an OB/GYN, I imagine that those persuing obstetrics are fascinated with pregnancy and birth, the process of growing and delivering new humans, and are interested in the pathologies that accompany all that stuff.
Similarly, someone fascinated with teeth might appreciate that there are so many different kinds of tissues in the mouth (most other parts of the body that size are pretty uniform), have a whole unique ecosystem, connect systemically to the rest of the body, etc. etc. Also, there is a large artistic and visceral component to dentistry; you sculpt teeth to replace the missing anatomy, you work with all kinds of materials to manipulate what you need. That's cool stuff!
Hope I made myself more clear. It will be a pretty bored and disgusted dentist that doesn't at least grow an appreciation for working inside the mouth! Ask any dentist; we'll get to the point where we feel so GOOD after fixing up a bombed-out mouth! To do that, you have to get in there and do your thing.
For those who are worried about bad breath and perio problems and all that; no one LIKES the stinkiness, but I imagine we adjust as we move on with our careers. We'd better get used to the gross stuff quickly! And it may take some longer than others, so it's fine to be queasy at first. Just like with gross anatomy....the first dissection is nasty, but then you realize that you'd better get over it in the next 10 seconds or you're already behind in the class!