An impacted tooth is a tooth that hasn’t fully emerged through the gum line because something is blocking its path. It may be stuck against bone, wedged into a neighboring tooth, or angled in a direction that makes normal eruption impossible. Wisdom teeth are by far the most common culprits, but canines and other teeth can become impacted too.
Why Teeth Become Impacted
The root cause is simple: not enough room in the jaw. Your teeth develop inside the bone and are supposed to gradually push through the gum into their correct position. When the jaw is too small or the teeth are too large, the last ones to arrive have nowhere to go. Wisdom teeth, which typically try to emerge between ages 17 and 25, are the most frequent victims because they’re the last in line.
Genetics plays a major role in jaw size and tooth dimensions, but diet matters more than most people realize. Populations that shifted to softer, more processed diets show higher rates of third molar impaction. Softer foods require less chewing force during childhood and adolescence, which means less mechanical stimulation for jaw growth. The result is a smaller jaw with the same number of teeth trying to fit inside it.
Losing baby teeth too early can also set the stage for impaction later. When a baby tooth falls out or is extracted before the permanent tooth beneath it is ready, the neighboring teeth drift into that gap. By the time the permanent tooth tries to come in, its reserved space has shrunk or disappeared entirely.
Which Teeth Get Impacted Most Often
Lower wisdom teeth (mandibular third molars) account for roughly 65% of all impacted teeth. They sit at the very back of the jaw where space is tightest and bone is dense. Upper wisdom teeth are also commonly impacted, though they tend to cause fewer complications because the surrounding bone is softer and less confining.
Upper canines are the second most commonly impacted teeth, making up about 18.5% of cases. Unlike wisdom teeth, canines play a visible role in your smile and your bite, so the treatment approach is usually very different. Rather than extraction, the goal is often to guide the canine into its proper position using a combination of minor surgery and orthodontics.
Types of Impaction
Dentists classify impacted teeth by the angle at which the tooth is stuck, because that angle determines how much trouble the tooth is likely to cause and how difficult it will be to remove.
- Vertical impaction: The tooth is pointing in the right direction but simply can’t push through, usually because the tooth above or below it is in the way or there isn’t enough room.
- Mesioangular impaction: The tooth is tilted forward, angling toward the front of the mouth. This is the most common pattern for lower wisdom teeth and often puts pressure on the neighboring molar.
- Distoangular impaction: The tooth is tilted backward, toward the throat. These can be trickier to extract because of the angle and the surrounding bone.
- Horizontal impaction: The tooth is lying completely on its side, parallel to the jawbone. This is the most severe orientation and almost always requires surgical removal.
Depth matters too. Some impacted teeth sit just beneath the gum (a soft tissue impaction), while others are fully encased in jawbone (a bony impaction). Deeper impactions generally mean a more involved extraction and a longer recovery.
Symptoms to Watch For
Many impacted teeth cause no symptoms at all, especially in the early stages. You might go years without knowing a tooth is stuck below the surface. When symptoms do appear, they typically include red, swollen, or bleeding gums around the back of the mouth, persistent jaw pain, headaches, bad breath or an unpleasant taste, and difficulty opening your mouth fully. Swollen lymph nodes in the neck can also develop if infection sets in.
One of the most common complications is pericoronitis, an infection of the gum tissue that partially covers an emerging tooth. Food and bacteria get trapped under the flap of gum, creating a painful, swollen area that can spread to the jaw, cheek, or throat. Pericoronitis tends to flare up repeatedly until the underlying impaction is addressed.
Left untreated, impacted teeth can also push on adjacent teeth and shift your alignment, develop cysts in the jawbone, or cause decay in the neighboring molar where the two teeth press together and create a pocket that’s impossible to clean.
How Impacted Teeth Are Diagnosed
Most impacted teeth are discovered on routine dental X-rays before they ever cause problems. A standard panoramic X-ray captures the entire jaw in a single image and shows the position, angle, and depth of any unerupted teeth. This is why dentists recommend panoramic imaging for teenagers: it reveals developing wisdom teeth and canines early enough to plan ahead.
For more complex cases, particularly when an impacted tooth sits close to a nerve canal or a sinus cavity, a cone beam CT scan provides a detailed three-dimensional view. This type of imaging is especially useful for surgical planning, letting the dentist or oral surgeon map the exact relationship between the impacted tooth and surrounding structures before making an incision.
Treatment Options
Not every impacted tooth needs to be removed. If the tooth is fully buried in bone, causing no symptoms, and isn’t threatening nearby teeth, your dentist may recommend monitoring it with periodic X-rays. This is more common with older adults whose impacted wisdom teeth have been stable for decades.
When treatment is needed, the approach depends on which tooth is impacted and what the goal is. For wisdom teeth, surgical extraction is the standard. The procedure involves numbing the area (or using sedation), making a small incision in the gum, removing any bone covering the tooth, and extracting the tooth, sometimes in pieces to minimize the amount of bone that needs to be removed.
For impacted canines, the strategy is usually exposure and bonding. A surgeon uncovers the buried tooth and attaches a small bracket to it, connected to an orthodontic wire. Over several months, gentle traction guides the canine down into its correct position in the arch. This is more involved than a simple extraction but preserves a tooth that’s important for both appearance and chewing function.
What Recovery Looks Like
After surgical extraction of an impacted tooth, expect some bleeding for up to 24 hours. The first two days require the most care: keeping gauze on the site, eating soft foods, avoiding straws (the suction can dislodge the blood clot), and managing swelling with ice. Pain typically peaks in the first couple of days and starts improving after day three.
Around seven to ten days after extraction, new tissue called granulation tissue forms over the socket, protecting it while bone slowly fills in underneath. A follow-up appointment at the two-week mark lets your dentist confirm that healing is on track. For impacted wisdom teeth, full recovery often takes several weeks, and the deeper the impaction, the longer the process. Most people return to normal activities within a few days, though the surgical site continues to remodel beneath the surface for months.
The most important thing to avoid during recovery is dry socket, a condition where the protective blood clot is lost too early, exposing the underlying bone. This causes intense, throbbing pain that radiates to the ear and typically starts three to four days after surgery. Smoking, spitting, and drinking through straws all increase the risk.