The edges of my tongue are scalloped like a gear. Is it a disease?

In most cases it is not a disease but indentations left where the tongue presses against the teeth, called a crenated tongue. It occurs with habits such as pushing the tongue against the teeth, clenching or grinding, tongue tension from stress, and swelling of the tongue, and if there is no pain you can simply monitor it without treatment. Day to day, 1) learning to rest the tip of your tongue lightly against the palate and 2) reducing clenching help the indentations fade. However, please come in if 1) the same area becomes raw or painful, 2) there is also a white or red patch that has not healed in 2 weeks, or 3) your tongue feels persistently swollen, as another condition may need to be ruled out.