Gp probably has the POTENTIAL to make the most, although on average they rarely do because reputation is half the game (Dorfman,etc...)
Pedo depends a LOT on how fast you are, probably most stressful of specialties IMO.
Endo will make a lot on average, but probably never the most because work is so precise and assistants can't do much. Overhead is low though.
Ortho has assistants to everything and probably has the least working days, but markets are saturated in different areas.
Perio can make as much money as they want, but again assistants can't do much and have to have lots of connections for implant cases= longer time to get to high earning level.
I noticed no one mentioned Prosthodontics, although surprisingly I heard it can make the most- but I don't know how that is possible.
Each has pros and cons.
This is the best reply I have seen. I'd like to add a few of my own thoughts.
OMFS is #1 for potential and average income. But that doesn't seem to be part of the discussion.
Pedos can indeed make a lot of $$. But it is also very difficult work. If you have the gift and the desire to do it, then you get rewarded. But again, it is stressful, and it takes a very particular personality. These residencies are not a "decision" in the same sense that ortho/endo/perio are....you really need to have that special ability. There's a reason that GPs refer so much Pedo out to the specialists.
Endo has long been extremely lucrative, particularly due to the crazy-low overhead. It is oft-knocked for being repetitious - but if you enjoy something, doing the same thing over and over might be ideal. One problem on the horizon for Endo is that dental implants are making people more 'okay' with losing a tooth. When people hear about their friend who had a $1k root canal, then an expensive apicoectomy, and THEN a dental implant....some pts are skipping right to the dental implant. This has Endo worried - which is why you now see endodontists in implant placement CE courses (crazy times).
Ortho is lower stress - almost no chance of medical emergency in your office. A very different type of dental practice. It can also be easily influenced by the economy - many orthodontists do extremely well, but some new grads are having a tough time finding enough pts.
Perio is an odd duck. They can be very successful, but some don't seem to be - in many cases, it seems to be a function of how many implants the doc places. It's an easier residency to get.
Prosthodontics is, in my opinion, something you do for the love and NOT the money. As mentioned, a prosth is little more than a GP with advanced training in prosthetics - the earning potential is not much more than a GP, especially considering the opportunity cost of residency. Some prosth practices end up looking a lot like GP practices.
Discussing specialties is fun stuff.