Wisdom teeth, also known as third molars, are the last set of permanent teeth to emerge. They typically appear in late adolescence or early adulthood, between the ages of 17 and 25. Located at the very back of the mouth, behind the second molars, they are a normal part of human dental development.
Can Wisdom Teeth Stay Un-Erupted?
Yes, wisdom teeth can remain un-erupted, meaning they do not fully break through the gum line. This is common, with approximately 80% of young adults having at least one wisdom tooth embedded within the jaw. When a wisdom tooth does not emerge properly, it is often referred to as an “impacted” tooth.
A wisdom tooth might also not be present if it never formed at all. This condition, known as agenesis, means the tooth simply did not develop within the jawbone. Therefore, a wisdom tooth can be present but un-erupted, or entirely absent from the start.
Why Wisdom Teeth Might Not Erupt
One reason wisdom teeth fail to erupt is a lack of sufficient space in the jaw. As human jaws have evolved to become smaller, there is often inadequate room for these molars to emerge correctly. When the path of eruption is obstructed, the tooth becomes impacted, meaning it is trapped partially or entirely within the bone or gum tissue.
Impaction can occur in several ways, depending on the angle at which the tooth develops. A mesial impaction, the most common type, involves the tooth angled forward towards the front of the mouth. A distal impaction, which is rarer, means the tooth is angled backward. In a horizontal impaction, the tooth lies completely on its side, often pressing against the adjacent molar, which can be particularly problematic. A vertical impaction indicates the tooth is in an upright position but remains trapped beneath the gums or bone.
Agenesis, the complete absence of wisdom teeth formation, is another reason for non-eruption. This happens due to genetic factors, where the tooth bud simply never develops in the jaw. While impaction is due to physical limitations, agenesis means the tooth was never present. Estimates suggest 5% to 41% of people may be missing at least one wisdom tooth due to this genetic trait.
What Happens If They Don’t Erupt?
Un-erupted wisdom teeth can lead to a range of potential issues, especially if impacted. One common problem is pain and swelling, which can arise from the pressure the tooth exerts as it tries to erupt or from associated inflammation. Impacted teeth, particularly those partially erupted, create spaces where food particles and bacteria can become trapped, leading to infections like pericoronitis. This infection can cause localized pain, swelling, and sometimes a bad taste in the mouth.
Beyond immediate discomfort, un-erupted wisdom teeth can also damage neighboring teeth. They might push against adjacent second molars, potentially causing cavities, bone loss, or root resorption. Pressure can also contribute to the crowding or misalignment of other teeth. Less commonly, fluid-filled sacs called cysts can form around an impacted wisdom tooth, which may damage the jawbone and surrounding structures. Rarely, a noncancerous tumor can develop.
Many un-erupted wisdom teeth remain asymptomatic, meaning they do not cause noticeable symptoms. However, even asymptomatic teeth can harbor underlying disease, such as gum inflammation or decay, which may progress without overt signs. Dentists typically use clinical examination and dental X-rays, such as panoramic X-rays, to assess the position and condition of wisdom teeth and detect any problems.
Dental Care for Un-Erupted Wisdom Teeth
The management of un-erupted wisdom teeth depends on their status and whether they are causing problems. If an un-erupted wisdom tooth is asymptomatic and shows no signs of disease or potential complications, dentists may recommend a “watch and wait” approach. This involves regular dental check-ups and periodic X-rays to monitor the tooth’s position and ensure no issues develop.
Extraction is often recommended if un-erupted wisdom teeth cause pain, recurring infections, or damage adjacent teeth. It is also advised if there is evidence of cysts, tumors, or significant decay that cannot be treated. Surgical removal is typically necessary for impacted teeth, as they are often embedded in the jawbone or gums.
The procedure for removing impacted wisdom teeth can involve making an incision in the gum and sometimes removing a small portion of bone to access the tooth. Extraction is generally easier and carries fewer risks in younger individuals, typically between 17 and 25, because the roots are not yet fully formed and the surrounding bone is less dense. This can lead to a smoother procedure and a quicker recovery.