Right up there alongside doctors in terms of high-paying salaries with a chance to retire early are orthodontists. They can open a private dental practice or join an existing team of dentists and earn right out of college. The salaries typically start high and are comparable to what physicians earn. Since dental school is costly, tuition is a challenge, and student loans may exceed $100,000. The earning potential is high, though, and while earning more than $100,000 a year it is possible to repay those loans quickly. Once that major source of debt is out of the way you can begin saving for retirement at a fast clip and retire early.