Third molar
Third molar teeth (commonly referred to as wisdom teeth) consist of the mandibulal and maxillary third molars; they usually appear between the ages of 17 and 25. They are called wisdom teeth because usually they come in when a person is between age 17 and 25 or oder—old enough to have supposedly gained some wisdom. Most adults have four wisdom teeth, but it is possible to have more or fewer. Absence of one or more wisdom teeth is an example of hypodontia. Any extra teeth are referred to as supernumerary teeth. Wisdom teeth commonly affect other teeth as they develop - becoming impacted or "coming in sideways." They are often extracted when this occurs.
Wisdom teeth are extracted for two general reasons: either the wisdom teeth have already become impacted, or the wisdom teeth could potentially become problematic if not extracted. Potential problems caused by the presence of properly grown-in wisdom teeth include infections caused by food particles easily trapped in the jaw area behind the wisdom teeth where regular brushing and flossing is difficult and ineffective. Such infections may be frequent, and cause considerable pain and medical danger. Other reasons wisdom teeth are removed include misalignment which rubs up against the tongue or cheek causing pain, potential crowding or malocclusion of the remaining teeth (a result of there being not enough room on the jaw/ in the mouth),as well as orthodontics.
A panoramic x-ray (aka "panorex") is the best x-ray to view wisdom teeth and diagnose problems.