Wisdom teeth, formally known as third molars, are the final set of teeth to emerge into the mouth. They are located at the back of both the upper and lower jaws. Their late appearance and placement often lead to various complications, which is why understanding their location provides insight into why they frequently require monitoring or removal.
Defining the Third Molars
The precise anatomical position of a wisdom tooth is directly behind the second molar in each quadrant of the mouth. A person generally has four third molars in total: one in the upper right, one in the upper left, one in the lower right, and one in the lower left section of the dental arch. They are the farthest back of all the molars. The common name “wisdom teeth” stems from the fact that they appear much later than all other permanent teeth. This timing, associated with late adolescence or early adulthood, was historically linked to reaching an age of presumed maturity or “wisdom”.
The Eruption Timeline
The typical window for the third molars to break through the gums is between the ages of 17 and 25, a period often called late teens to early twenties. This late timing distinguishes them from the first and second molars. The development of the wisdom tooth itself begins much earlier, but the final eruption phase coincides with the completion of jaw growth. Because the jaw is often done developing by this time, there may not be adequate space left to accommodate these final teeth.
Why Their Location Causes Issues
The primary reason for dental problems is that the third molars are trying to erupt into an area that is already crowded. When there is insufficient room at the back of the jaw, the wisdom tooth can become “impacted,” meaning it is unable to fully emerge. This impaction can manifest in several ways, such as the tooth growing at an angle toward the neighboring second molar or remaining completely trapped beneath the gum line and jawbone. An impacted wisdom tooth can press against the adjacent molar, potentially causing damage or crowding the other teeth. Furthermore, when a third molar partially erupts, it creates a small flap of gum tissue that is difficult to clean, allowing food particles and bacteria to accumulate. This accumulation leads to inflammation and infection of the surrounding gum, a condition known as pericoronitis, often necessitating monitoring or surgical removal.