Mamelons are little bumps on the cutting edge of your incisors (front teeth). Everyone has them when their teeth first erupt–it’s what helps the teeth break through the gums. For most people, mamelons naturally wear off through usage, over time.
Some poor kids mamelons…
I filed mine down, because I hated them. But, you can still see the lines.
“Mamelon” comes from the French word for nipple, which is derived from the same root word that gives us “mammary” and “mammal”, and just goes to show you that dentists are perverts who think your teeth bumps look like boobs.