The wisdom teeth, or third molars, are the last set of teeth to emerge, typically appearing between the ages of 17 and 25. While their enamel and dentin composition are not inherently weaker than other molars, they are significantly more vulnerable to fracture. Their challenging position and development make them highly susceptible to conditions that compromise their integrity and increase the likelihood of breakage.
Unique Structural Vulnerabilities
The location of wisdom teeth at the back of the mouth creates a major vulnerability, making them difficult to access with a toothbrush or floss. This poor accessibility allows food particles and plaque to accumulate easily, leading to a high rate of decay (caries) in the third molars. As decay progresses, it erodes the protective enamel and underlying dentin, significantly weakening the tooth structure. A tooth compromised by a large cavity is much more likely to break under normal chewing forces.
Many wisdom teeth do not fully erupt into the mouth, a condition known as partial impaction. A partially erupted tooth leaves the gums covering part of the crown, creating a flap where bacteria thrive and accelerate decay. The persistent presence of bacteria and resulting infection, known as pericoronitis, can further weaken the surrounding bone and the tooth itself.
The formation of the third molar can also contribute to instability. Wisdom teeth frequently exhibit atypical root systems, sometimes featuring fused, curved, or unusually thin roots compared to the first and second molars. This irregular anatomy reduces the tooth’s structural stability and its ability to withstand the heavy forces of mastication. Furthermore, some third molars have smaller crowns, which may be less robust than neighboring teeth, increasing the risk of structural failure.
Situational Causes of Fracture
A common cause of fracture involves the chronic pressure exerted by an impacted tooth that is unable to fully emerge. When a wisdom tooth grows at an angle, it presses constantly against the adjacent second molar or the jawbone. This constant pressure over time can lead to micro-fractures in the wisdom tooth, or even damage the roots of the neighboring molar.
Acute forces also pose a significant risk, particularly when a wisdom tooth is already compromised by decay or a large filling. Fractures frequently occur when a person bites down on unexpectedly hard or dense objects, such as ice, unpopped popcorn kernels, or hard candies. The sudden, high-impact force can be enough to cause a catastrophic break in a structurally weakened molar. Even habitual teeth grinding, or bruxism, can weaken a wisdom tooth over time, making it prone to fracture during normal function.
A tooth can also break during its removal, which is a complication of the extraction process. This happens because the tooth is often brittle from decay, or its roots are severely curved or deeply embedded in the bone, increasing the difficulty of the procedure. The application of surgical forces required to remove a deeply impacted tooth can cause the crown or roots to fracture into multiple pieces. In rare cases, excessive pressure during a difficult extraction, especially of lower molars, can even result in a fracture of the jawbone itself.
Immediate Steps Following a Break
If you feel a sudden, sharp pain, notice a jagged edge with your tongue, or experience extreme sensitivity, you should suspect a broken wisdom tooth. The first immediate step is to gently rinse your mouth with warm salt water, using about a half-teaspoon of salt in eight ounces of water. This action helps to clean the area, reduce the presence of bacteria, and soothe any irritated gum tissue.
If there is any bleeding from the site, apply gentle, steady pressure using a folded piece of sterile gauze for approximately 15 to 20 minutes. To manage pain and reduce potential swelling, you can place a cold compress or an ice pack on the outside of your cheek near the affected area. Over-the-counter pain relievers, such as ibuprofen or acetaminophen, may be taken to alleviate discomfort until a dental appointment can be secured.
It is necessary to contact a dental professional immediately for an assessment, as a broken tooth can quickly lead to infection. The fracture creates an opening for bacteria to penetrate the pulp chamber, which can result in an abscess that may spread to the jawbone. Treatment for a broken wisdom tooth is almost always extraction, as they are rarely restored due to their difficult location and poor prognosis.