The country's first president rarely smiled, and his dentures may have been why. Washington wore dentures made of horse, cow and human teeth, which forced his lips to protrude awkwardly. What's more, he considered dentures a sign of weakness.

The main author of the Declaration of Independence kept his teeth in remarkably good condition for the period. When Jefferson was 81 years old, he said he’d only lost a single adult tooth in his lifetime.

The second president of the U.S. didn't have a full set of teeth. There were two factors that contributed to his tooth decay: He loved sweets, and he believed throwing up was the cure for a number of diseases. Because Adams refused to wear dentures, it was difficult to understand him when he spoke.

You've probably heard of his nighttime ride to alert the colonial militia during the Revolutionary War. But did you know that Paul Revere was also a dentist? The early patriot not only worked as a silversmith in Boston but also cleaned teeth and sold dentures. Plus, he's also thought to be the first person to identify a body by its teeth. He verified the death of his friend, Dr. Joseph Warren, when he recognized the dental bridge he had made for Warren.