Wisdom teeth, also known as third molars, are the last set of teeth to emerge, typically between the ages of 17 and 25. For many, this emergence is accompanied by sharp discomfort, particularly when trying to bite down or chew food. This pain is a direct result of mechanical pressure and biological reactions occurring at the back of the jaw. Understanding the causes is the first step toward professional treatment and relief.
Specific Reasons Why Biting Causes Pain
The most common cause of acute pain when biting down is pericoronitis, the inflammation of the gum tissue surrounding a partially erupted wisdom tooth. When the tooth fails to break fully through the gum line, a flap of tissue, known as the operculum, forms over the crown. This creates a sheltered space where food particles and bacteria become trapped, leading to infection. Chewing causes the opposing tooth to press directly onto this swollen, infected tissue, resulting in sudden pain.
Another source of discomfort is the physical pressure exerted by an impacted tooth. An impacted tooth is blocked from fully erupting by bone, gum tissue, or an adjacent tooth. The wisdom tooth often grows at an angle, pushing against the second molar or the jawbone. The pressure generated during biting exacerbates this constant contact pain. Horizontal impactions, where the tooth lies completely sideways, are especially painful because the crown constantly applies force to the root of the neighboring tooth.
Tooth decay and fracture can also cause pain when chewing. Wisdom teeth are difficult to clean due to their far-back position, making them susceptible to deep cavities. When decay reaches the nerve pulp inside the tooth, the pressure or temperature change caused by biting can elicit sharp pain. Similarly, if the tooth or an existing filling has a fracture, the force of biting can cause temporary movement in the cracked structure, irritating the underlying dental pulp.
Immediate At-Home Relief Measures
While waiting for a dental appointment, several temporary measures can help manage acute pain. Rinsing the mouth with a warm saltwater solution is a recommended first step. The warm water soothes irritated tissue, and the dissolved salt creates an osmotic effect, drawing out excess fluid to temporarily reduce swelling. The alkaline environment created by the salt also inhibits bacterial growth, providing a mild cleansing effect.
Over-the-counter non-steroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen, are effective because they reduce inflammation, not just mask the pain. These medications work by inhibiting cyclooxygenase (COX) enzymes, which create prostaglandins—chemical compounds that mediate pain and inflammation. By reducing this inflammatory response, NSAIDs directly address a major component of the wisdom tooth discomfort.
Applying a cold compress to the outside of the cheek can provide localized relief. The cold temperature causes blood vessels to constrict, limiting blood flow to the inflamed area and minimizing external swelling. Apply the compress in 15 to 20-minute intervals to prevent skin damage. Finally, modify your diet to include only soft foods, such as yogurt or soup, and chew on the side opposite the painful tooth to prevent further trauma.
Dental Assessment and Professional Solutions
Addressing wisdom tooth pain begins with a professional assessment, relying heavily on diagnostic imaging. A panoramic X-ray is typically the first image taken, providing a broad view of the entire jaw to assess the wisdom tooth’s positioning relative to the jawbone and nerve canals. A periapical X-ray may also be used to provide a detailed view of the tooth root and surrounding bone structure, necessary for identifying decay or localized bone loss.
X-rays reveal the specific type of impaction, which guides the treatment plan. Mesial impaction, where the tooth is angled toward the front of the mouth, is the most common type. Horizontal impaction, where the tooth lies completely sideways, often requires immediate surgical planning due to pressure on the adjacent molar. A vertical impaction means the tooth is in the correct orientation but is trapped beneath the gum line.
For mild pericoronitis where the tooth is expected to erupt normally, non-extraction treatments are used first. This involves professional irrigation to flush out trapped debris and bacteria from the operculum. If the infection is more severe, the dentist will prescribe oral antibiotics like amoxicillin. If the gum flap repeatedly becomes infected, a minor surgical procedure called an operculectomy may be performed to remove the excess tissue.
Extraction is the most permanent solution when the tooth position is unfavorable or the infection is recurrent. It is recommended for severe impactions, such as horizontal types, or when the tooth causes irreversible damage to adjacent teeth. Removing the source eliminates the possibility of future pericoronitis and chronic damage.
Recognizing Urgent Warning Signs
While most wisdom tooth pain can be managed until a dental appointment, certain symptoms indicate a rapidly escalating infection requiring immediate emergency care. The inability to open the mouth fully, known as trismus, suggests the infection has spread into the surrounding jaw muscles. Swelling that rapidly spreads into the face, neck, or under the chin is a significant warning sign, indicating a potentially dangerous infection extension that could compromise the airway.
A high fever above 101°F or chills alongside the pain indicates a systemic infection, no longer localized to the mouth. Difficulty or pain when swallowing or breathing signals the infection is encroaching on the throat area, which is a life-threatening emergency. If these severe signs are present, visit an emergency room or an urgent dental clinic immediately.