If you think you might have cracked a tooth, it’s important to get to a dentist right away. Putting it off can lead to significant oral health problems, including infection and even tooth loss. How do you know if you have, indeed, cracked a tooth? It can be difficult to tell at first. You can’t always see cracks, but pain when you chew, sensitivity to hot and cold, swelling around the impacted tooth and discoloration are all telltale signs something isn’t right.