Okay, I'll bite, even though I'm scared $#!+less of getting into an Internet flame war over this issue. Only because I once was a dental student (as my handle would suggest) and realized that internal medicine is a better fit for me and now I'm just a lowly pre-med. I know some of you are going to say "You're such a dumb@$$ for leaving DENTISTRY for INTERNAL MEDICINE!!" but here are my reasons for doing so:
1) No on-call: Yes, it's true that there's no "call" per se if you're a dentist (unless maybe you decide to specialize in oral surgery), and that's one of the major reasons why I chose dentistry in the first place. But after drilling tooth after tooth and realizing that I'm more oriented toward the cerebral rather than the procedural, I realized that I'd much rather be on call at 2AM in the morning diagnosing some patient's life-threatening condition than have to wake up at 8AM in the morning and look forward to eight hours of drilling and filling.
2) Freedom to choose your work schedule: Yes, there's freedom in terms of determining what hours you work as a dentist, but for me the answer became "no hours," because I just couldn't stomach looking at another tooth or holding the drill in my hand one more time.
3) Money $$$: Shameful as it is to admit it, the reason I went into dentistry was mainly for the $$. But what people (including me, until a while ago) don't realize is that dentistry is HARD WORK. It is pure physical labor for the most part, and after drilling for just a couple of hours (not even a whole 8-hour day), my wrists were hurting, my neck was sore, and I was miserable. It came to a point where I felt like you just couldn't pay me enough to touch another tooth. And that's when I decided to leave and pursue medicine instead, because I would rather be studying renal physiology than learning about dentures, but unfortunately, there was no way I could just skip the lab work and study physiology instead.
4) 4 years of school: Both medicine and dentistry require 4 years of post-college studying, and I had already completed part of my dental degree. So why did I leave for the wonderful world of unemployment and MCAT studying? Because I realized that I'd rather spend 4 years in med school, plus residency, learning about and applying knowledge about the WHOLE human body, than spend another minute with my drill. Besides, residency is paid so it's not really "school" in my opinion, although it's where the most learning takes place. It will be hellacious, I'm sure, but it will pay off in the end. We'll all be 45 some day any way, so might as well enjoy the journey.
None of this is to say that I don't appreciate or respect dentists/dentistry. It is HARD WORK, people. I definitely didn't have the hand skills that really good dentists do, and more importantly, I just didn't care enough to develop those hand skills. All I wanted to do was to study in the library, not spend another hour in the dental lab. This cemented my decision for me. Medicine vs dentistry is not a decision that you should make based on money on "lifestyle." Lifestyle means nothing if you don't enjoy your LIFE and don't feel like you're living your life to the FULLEST. You have to look inside of yourself and be honest with your strengths and weaknesses. I know that I'm a much better at diagnosis than I am at performing complex, millimeter-scale procedures, which is why I eventually choose the big picture (internal medicine) over the more detailed one (dentistry).
Of course, as in all pre-cautionary tales, YMMV.
Best,
rootcanalz