Wisdom teeth — your third molars — are the last adult teeth to arrive, usually between your late teens and mid-twenties. By the time they're ready to come through, there's often simply nowhere for them to go.
When a jaw doesn't have enough room, a wisdom tooth can come through at an angle, only partially emerge, or stay trapped beneath the gum entirely. Dentists call this impaction, and it's one of the most common reasons a wisdom tooth becomes a problem rather than just another tooth. A single panoramic X-ray usually tells us everything we need to know about how yours are sitting.