Wisdom teeth, or third molars, are the last set of molars that typically emerge in late adolescence or early adulthood, usually between ages 17 and 25. We have them as our ancestors needed them for grinding tough food. 

They can act as a replacement if other molars are lost or damaged early. The most common issue we see is when they are impacted, that is, when there is not enough room for the tooth to emerge properly, leading to pain and potential infection. 

They can push other teeth out of alignment and as they are often hard to reach for cleaning, they are prone to cavities and gum issues. The main reasons we remove them is when there is persistent discomfort, swollen, bleeding gums or there are deep cavities that are hard to treat.