Teeth may become impacted when they fail to erupt or develop into the proper functional location. As such, impacted teeth are considered nonfunctional, abnormal, and pathological. The mandibular third molar is the most common tooth to become impacted. The cause of impacted third molars is thought to be inadequate space. Several studies indicate that a change from a coarse, attritive diet to a modern, refined diet has lead to an increased incidence of impacted teeth. Interproximal attrition allows for greater mesial migration of teeth and space for third molar teeth. Teeth that fail to attain a functional position may be pathological and should be considered for removal. The indications for removing impacted teeth can be divided into those of acute or chronic pathology. Impacted third molars are often associated with pain, infection, cyst formation, benign tumors, root resorption, bone loss, periodontal disease, and caries. The decision to surgically remove impacted third molars is often unclear. There are no absolute treatment protocols established. The dentist must consider a variety of factors and make an informed decision with the patient. Most experienced clinicians combine objective data and common sense to arrive at a logical treatment plan. The purpose of this article is to discuss factors related to impacted teeth and help the orthodontist understand the general management of impacted third molars. The decision for surgery will be assisted by an understanding of all of the risk factors associated with impacted teeth and presenting the options to the patient.