Types of Wisdom Tooth Impactions

Wisdom tooth impaction is a common, uncomfortable dental problem that affects the third set of molars, which are the teeth at the very back of the mouth.

Wisdom teeth typically appear when a person is between the ages of 17 and 21, when their jawbones have grown large enough to fit the third set of molars. Sometimes teeth break through the gum line, or “erupt,” without a problem and the teeth come in perfectly aligned because there is enough room on the jaw to accommodate the extra teeth. Much of the time, though, the teeth have trouble breaking through the gum and do not fully grow in. Oral surgeons refer to these as impacted wisdom teeth.

In some cases, impacted wisdom teeth cause pain or interfere with chewing. In other cases, the impacted wisdom tooth can affect other teeth in the mouth, and even cause damage to those surrounding teeth.

Oral surgeons can surgically remove these impacted wisdom teeth so that they do not cause pain or other problems. Surgery is not always required, however, depending on the discomfort the patient experiences and the type of impacted wisdom tooth he or she may have. When surgery is required, the oral surgeon may administer a local anesthesia, IV sedation, or general anesthesia to help the patient avoid pain and remain calm.

There are four main types of impacted wisdom teeth. Some types of wisdom teeth cause discomfort. Other symptoms associated with all four types of impacted wisdom teeth include swollen and bleeding gums, headaches, swelling around the jaw area, and swollen glands in the neck and shoulders.

Four Main Types of Impacted Wisdom Teeth

Vertical impaction

Vertical impaction occurs when a tooth is positioned almost perfectly, but still has a hard time pushing through the gum. Vertically impacted wisdom teeth rarely need extraction because they are nearly upright. An oral surgeon may recommend surgery if the impacted tooth pushes against the bottom of the molar in front of it or causes pressure against the bone. Surgery is usually performed under local anesthesia but extremely nervous patients may prefer sedation.

Mesial impaction

Of all the types of impactions, mesial impaction is the most common.  In this type of impaction, the wisdom tooth is tilted so that the top of the tooth angles towards the front of the mouth. This causes the wisdom tooth to press against the nearby molar.

The angle of the tooth determines whether the impacted tooth will require extraction.

Distal impaction

Distal impaction is the least common type of wisdom tooth impaction. It is the opposite of mesial impaction in that the top of the wisdom tooth angles towards the back of the mouth.

As with mesial impaction, the angle of the tooth determines whether extraction is necessary. A tooth standing at 0-degrees, which is perfectly positioned, would not require extraction because it should erupt well. One lying on its side at a 90-degree angle or nearly a 90-degree angle would not break through the gum properly. Such a poorly positioned tooth would probably press against the bone eventually too.

Horizontal impaction

Horizontal impaction is typically the most painful type of impacted wisdom teeth, as the tooth lies completely on its side and presses into the molar in front of it. A wisdom tooth with horizontal impaction lies deep within the gum tissue, so the tooth may not be evident without x-rays.

The tooth is parallel to the jaw bone so, without removal, the horizontally impacted wisdom tooth may ultimately damage the surrounding teeth. When extracting a horizontal impaction, the oral surgeon may need to remove some of the bone, so the patient will need to undergo IV sedation or general anesthesia. After the procedure, patients may need painkillers to control discomfort. Antibiotics to reduce the risk of infection are sometimes necessary.

For more information on wisdom tooth impactions, consult with a dental professional or oral surgeon. Depending on the type and severity of the wisdom tooth impaction, the oral surgeon may recommend extraction.