Wisdom teeth often begin to move into position around age 17 to 25 – and it is normal for dentists to request an x-ray to determine their position within the bone of the jaw. When they sit fairly vertically beneath the gum, they could move nicely into place behind the second molars, so
if they are free of decay, there is no reason for removal.
What are impacted wisdom teeth?
Problems arise when they become impacted. These molars can be angled in the jaw – sometimes horizontally. As they try to erupt, or emerge from the gum, they push against the tooth in front, which then blocks their further movement. Such impaction can damage the second molar in front.
Why is impaction a problem?
An angled tooth can partially erupt which means part of it is visible and part remains under the gum. This can create a tight spot between it and the tooth in front which can be difficult to keep clean. Food trapping is common between the visible part of the tooth and the edge of gum that hides the remaining crown of the tooth, therefore both of these scenarios increase the chance of decay in the wisdom tooth, and in the case of a tight spot, also the tooth in front.
Where food trapping makes cleaning difficult, the gum can become irritated and inflamed. This is known as gingivitis.
If the dentist is recommending extraction, a panoramic x-ray is required. This is necessary to determine the exact orientation of the tooth, its roots, and also its relationship to an important nerve in the jaw. Usually, the topic of extraction comes up during a regular check-up and can generally wait to be scheduled around school, work or other commitments. Ideally it will be done before the roots are fully formed, and before decay or other problems set in.