Wisdom teeth are technically known as third molars. In the United States third molars are designated numerically as teeth #1, 16, 17, and 32 (indicated by the red dots above). Third molars usually erupt in the late teens or early twenties. Most people will have to get their third molars removed sometime during their lives because of infection, pathology, impaction, and damage or potential damage to adjacent teeth.
Why do we have wisdom teeth in the first place if we don't need them?
Much like the problematic appendix of the gastrointestinal system, it is proposed that wisdom teeth are byproducts of human evolution and dietary change. The jaws of primitive man were larger than those of modern man; therefore, third molars had enough room to grow in properly. Since raw foods predominated primitive man's diet, third molars were necessary for chewing and digestion.
Although the jaws of modern man are smaller than that of primitive man, the size of the teeth have essentially remained the same. Therefore, crowding often occurs where third molars develop.
Most people will form all four wisdom teeth; however, variations in the number of wisdom teeth that form among individuals can occur.
What are the reasons for removal of wisdom teeth?
Because of the lack of space for wisdom teeth, a variety of problems can develop. The most common problem is impaction of the wisdom tooth. An impaction occurs when a wisdom tooth fails to erupt normally. A wisdom tooth may be misaligned or simply held up by bone or gum tissue. When an abnormally erupting wisdom tooth is completely encased in bone, it is known as a full-bony impaction; when partially encased in bone, a partial bony impaction; and when encased in gum tissue alone, a soft-tissue impaction. Because of the frequent problems caused by wisdom teeth, the World Health Organization has classified impacted wisdom teeth as pathologic entities.
Abnormally erupting or impacted wisdom teeth frequently cause secondary problems that necessitate their removal. The most common secondary problem is infection. Because of the frequent lack of space for a wisdom tooth to erupt normally, food debris and bacteria can get trapped in spaces around the wisdom tooth that cannot be reached for cleaning. This can lead to infection of the gum tissue overlying the wisdom tooth (pericornitis) or infection of the bone surrounding the wisdom tooth (osteomyelitis). Sometimes the infection can spread to the soft tissues of the face and neck. Infections of the head and neck can become life threatening and frequently require hospitalization and surgical drainage.
An abnormally erupting wisdom tooth can also cause damage to the tooth in front of it (the second molar). A mesioangular or horizontal pattern of eruption can cause structural damage to the second molar. The destruction can become so severe, that removal of the second molar may become necessary as well. Often, this will necessitate the replacement of the second molar with a dental implant. An impacted wisdom tooth can also cause severe bone loss behind the second molar. This will require a bone graft when the wisdom tooth is removed.
The membrane surrounding an impacted wisdom tooth (known as the follicle) can also transform into a cyst or tumor. Although rare, the consequences of a cyst or tumor in the jaw can be devastating. Since cysts and tumors of the jaw bone tend to grow very slowly, symptoms usually do not occur until damage has occurred. These growths can cause cause permanent damage to adjacent teeth, bone, and nerves necessitating additional procedures or surgery other than removal of the wisdom tooth.
Whether or not wisdom teeth can cause your other teeth to become crowded is a topic of controversy. In general, potential crowding of your permanent teeth itself is not an indication to remove your wisdom teeth. Your permanent teeth can drift or crowd even after your wisdom teeth have been removed. If you have had orthodontic treatment, it is wise to continue wearing your retainer after your wisdom teeth are removed.
To view actual cases click here: Problems Associated With Third Molars
When should someone get their wisdom teeth removed?
The best time to get your wisdom teeth removed is before symptoms or damage occur. Most people have their wisdom teeth removed in the late teens or early twenties. If symptoms occur, your wisdom teeth should be evaluated for removal immediately.
It is a known fact that delayed removal of wisdom teeth is associated with a higher frequency of complications (see complications below). Therefore, every person should have their wisdom teeth evaluated by the age of seventeen.
What are the complications of wisdom tooth removal?
Major complications related to the removal of wisdom teeth are rare. However, the degree of risk depends on the individual patient's own anatomy and preexisting conditions. The tables below demonstrate the minor and major complications related to the removal of wisdom teeth.
When evaluating any surgical procedure one must weigh the benefits of surgery against the risks of surgery.
What is dry socket?
Dry socket is a painful condition that follows the removal of wisdom teeth. Dry socket or alveolitis occurs when the blood clot is dislodged from the tooth extraction site leaving bare bone exposed. This condition is most common in the lower wisdom tooth area although it can occur following the removal of any tooth.
Dry socket is more frequent in individuals older than 30. People who smoke or fail to follow post-operative instructions are more likely to develop dry socket. Dry socket may occur 5-10% of the time regardless of taking every precaution to avoid this condition. It is characterized by a throbbing ache that radiates up and down the jaw and frequently into the region of the ear.
Fortunately, dry socket is easily treated. The doctor will wash any debris out of the tooth socket and place a medicinal salve into the socket. Symptoms are relieved rapidly. Dry socket usually resolves after one treatment; however, repeat treatments may be necessary.