What Is an Impacted Tooth?

A tooth is impacted when it has not come through the gum properly and is physically stopped from doing so. Something is in its way: the neighbouring tooth, dense bone, or simply a lack of space in the jaw. The tooth may be partly through, or entirely under the gum.

Any tooth can be impacted, but the usual ones are the third molars, known as wisdom teeth, and the upper canines, the pointed teeth beside the front ones. An extra tooth, or a lower premolar, can occasionally be impacted as well.

Impacted does not mean decayed or diseased. It describes a tooth that is stuck, and whether that matters depends on where it is and what it is doing.

The word is also used for teeth that are only partly through. A partly erupted tooth is not fully impacted, but it can behave in a similar way, because the gum still overlaps part of it and the tooth cannot be cleaned properly.

Dentists describe an impacted wisdom tooth by its angle. It can lean forward towards the second molar, lie flat (horizontal), point backwards, or sit upright but trapped. A forward or horizontal tooth presses on the one in front, and is the most likely to damage it.

They also describe how it is covered. A soft tissue impaction is a tooth that has enough bone around it to come through, but gum tissue is still covering all or part of the crown. A bone impaction is a tooth that is held in the jawbone, either partly or fully, and has to have bone removed to get it out.

The type matters because it decides how difficult removal is, if removal is needed at all. A soft tissue impaction is usually simpler than a deep bone impaction lying against the nerve canal.

Some people have more than one impacted tooth, and the pattern is often similar on both sides of the mouth. This is one reason a single panoramic X-ray is useful, as it lets the dentist look at every tooth in the same picture.

Many impacted teeth cause no symptoms for years. They are found on an X-ray taken for another reason. The absence of pain does not always mean absence of a problem, because a cyst or damage to a neighbouring tooth can develop quietly.

When there are symptoms, they include pain or tenderness at the back of the jaw, a swollen or red gum that traps food, a bad taste or breath, difficulty opening wide, and sometimes pain felt in the ear or jaw. These are covered in pericoronitis and the wisdom tooth pain page.

Swelling that spreads, fever, or difficulty opening your mouth or swallowing needs same-day care. If breathing or swallowing is affected, go to a hospital emergency department.

An examination shows a tooth that is missing from its place, a gum bump, or a baby tooth that has not fallen out on schedule. An X-ray then shows the tooth itself. A panoramic X-ray (OPG) shows all the teeth at once and is the usual starting point.

A flat X-ray cannot show depth. When the position is unclear, or a tooth lies close to a nerve or the roots of other teeth, a 3D scan (CBCT) can show exactly where it is. That shapes the plan and the risk discussion.

Impacted canines are often suspected earlier, in a child who is around eleven to thirteen years old, when the canine has not come through but the baby one is still in place. An X-ray at that stage gives the most options.

Monitoring is reasonable for a buried tooth that shows no sign of disease and is not harming its neighbours. It means regular check-ups and periodic X-rays, not forgetting about it.

Removal is advised when an impacted tooth causes repeated infection, decay, damage to the tooth beside it, or a cyst. How an impacted wisdom tooth is taken out is covered in what happens during a tooth extraction.

An impacted upper canine is treated differently. The canine is important for the bite and the smile, so it is usually kept. A surgeon uncovers the tooth and an orthodontist attaches a small fitting to it, then braces gently guide it into its place over months. Removal is considered if the tooth is badly placed or damaging others. See braces and orthodontics.

Which option fits depends on the tooth, your age and what the images show. Call the clinic to ask how your case would be handled.