Wisdom teeth: Encyclopedia - Wisdom teeth

Wisdom teeth

Wisdom teeth are third molars that usually appear between the ages of 18 and 20 (although they may appear when older, or fail to appear at all). They are called "wisdom teeth" because they appear so late—much later than the other teeth, at an age where people are supposedly wiser than as a child, when the other teeth erupt. Often they need to be removed when they impact against other teeth—colloquially known as "coming in sideways".

Wisdom teeth are sometimes described as an example of a "vestigial" trait. Some argue that recent changes to softer diets which cause less wear on the teeth may be causing the third molars to be less useful, and, in fact, problematic in many humans. Alternately, it is possible that wisdom teeth were useful when it was common for humans to lose several teeth to decay by the age when they appear.

Although most people have 4 wisdom teeth, it is possible to have more or fewer. Supernumerary teeth are any extra teeth. [1] [2]

Wisdom teeth - Impactions

Impacted wisdom teeth fall into one of several categories. Mesial impaction is the most common form, and means the tooth is angled forward, towards the front of the mouth. Vertical impaction occurs when the formed tooth does not erupt fully through the gumline. Horizontal impaction occurs when the tooth is angled fully ninety degrees forward, growing into the roots of the second molar. Finally, distal impaction is the least common form, and means the tooth is angled backward, towards the rear of the mouth.

Impacted wisdom teeth may also be categorized on whether they are still completely encased in the jawbone. If it is completely encased in the jawbone, it is a bony impaction. If the wisdom tooth has erupted out of the jawbone but not through the gumline, it is called a soft tissue impaction.

Pericoronitis is a common problem in young adults with partial impactions. It occurs when the wisdom tooth has failed to erupt completely through the gum bed, allowing bacteria into an open space around the tooth, causing infection. Common symptoms include a swollen lump near the eruption site, stiffness of the jaw, bad odour or taste in the mouth and pain in the general area which may also run down the entire mandible and / or neck.

Wisdom teeth - Extraction

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. The extraction of wisdom teeth can sometimes be performed by a regular dentist, but more often the extraction must be performed by someone who specializes in oral and maxillofacial surgery. However, there are always risks associated with surgery, and some of these risks increase when extractions are performed on patients who have kept their wisdom teeth for a significant number of years. In many cases, anesthesia will be applied.

Wisdom teeth - Post-extraction problems

There are several problems that can (and in some cases will) manifest themselves after the extraction(s) have been completed. Some of these problems are unavoidable and natural, while others are under the control of the patient. The suggestions contained in the sections below are general guidelines that a patient will be expected to abide by, but the patient should follow all directions that are given by the surgeon in addition to the following guidelines. Above all, the patient must not disregard the instructions given to them; doing so is extremely dangerous and could result in any number of problems ranging in severity from being merely inconvenient (dry socket) to potentially life-threatening (serious infection of the extraction sites).

Wisdom teeth - Bleeding and oozing

Bleeding and oozing is inevitable and should be expected to last up to a day in duration. Rinsing out your mouth during this period is counter-productive, as the bleeding stops when the blood forms clots at the extraction sites, and rinsing out your mouth will most likely dislodge the clots. The end result will be a delay in healing time and a prolonged period of bleeding. Gauze pads should be placed at the extraction sites, and then should be bitten down on with firm and even pressure. This will help to stop the bleeding, but don't overdo it as it is possible to irritate the extraction sites and prolong the bleeding. The bleeding should decrease gradually and noticeably upon changing the gauze. If the bleeding lasts for more than a day without decreasing despite having followed the surgeon's directions, contact the surgeon as soon as possible. This is not supposed to happen under normal circumstances and signals that a serious problem is present.

Wisdom teeth - Dry socket

A dry socket is the event where the blood clot at an extraction site is dislodged or falls out prematurely. In some cases, this is beyond the control of the patient. However, in other cases this happens because the patient has disregarded the instructions given to them by the surgeon. Smoking, spitting or drinking with a straw in disregard to the surgeon's instructions can cause this. The extraction site will become irritated and pain will manifest at one level or another. The patient should contact their surgeon if they suspect that they have a case of dry socket; the surgeon can prescribe medication in topical form to apply to the affected site. If this is done, dry socket becomes only a mere annoyance, but without the medication dry socket can progress to an infection of the extraction site.

Wisdom teeth - Swelling

Swelling should not be confused with dry socket; although painful, swelling should be expected and is a sign that the healing process is progressing normally. There is no general duration for this problem; the severity and duration of the swelling vary from case to case. The instructions the surgeon gives the patient will tell the patient for how long they should expect the swelling to last, including when to expect the swelling to peak and when the swelling will start to subside. If the swelling does not begin to subside when it is supposed to, the patient should contact their surgeon immediately. While the swelling will generally not disappear completely for several days after it peaks, swelling that does not begin to subside or gets worse may be an indication of infection.

Adapted from the Wikipedia article "Wisdom teeth", under the G.N U Free Docmentation License. Please also see http://en.wikipedia.org/wiki