Pain when biting or chewing, known as occlusal pain, signals that a tooth, the surrounding gum and bone, or the jaw joint structures are under duress. The sensation can range from a momentary, sharp sting to a dull, persistent ache. Since this type of pain rarely resolves without professional intervention, recognizing the underlying causes is the first step toward restoring comfortable function.
Pain Originating Within the Tooth Structure
A frequent cause of biting pain is a structural issue with the tooth itself, often involving a compromised enamel or dentin layer. Cracked Tooth Syndrome (CTS) involves an incomplete fracture that may be nearly invisible. This crack causes pain because the two separate segments of the tooth flex independently when pressure is applied during biting. The movement of these fragments irritates the nerve endings within the dentin and pulp, often resulting in a sharp, transient pain that is most intense when the biting pressure is suddenly released.
Deep decay is another structural problem, where a cavity has progressed toward the inner dental pulp, which contains the nerves and blood vessels. When biting down, pressure forces fluid into the microscopic tubules of the dentin, creating a rapid change in pressure near the inflamed nerve tissue. If the decay is extensive, the structural integrity of the tooth is weakened, making it more sensitive to the force of chewing.
Occlusal interference occurs when recent dental work, such as a new filling or crown, is slightly too high. Even a minuscule difference in height causes the restoration to strike the opposing tooth prematurely, bearing an excessive amount of force upon closure. This disproportionate pressure is transmitted through the tooth’s root to the periodontal ligament, which anchors the tooth to the jawbone. The ligament becomes bruised, inflamed, and tender, leading to pain when the tooth is subjected to any pressure.
Pain Caused by Infection and Inflammation
Infections affecting the tissues around the tooth are a common source of biting pain. A periapical abscess, a pocket of pus that forms at the tip of the tooth root, is a prime example. As the infection spreads, the resulting inflammation and swelling create pressure within the jawbone, directly against the periodontal ligament. Biting down compresses this inflamed ligament, causing severe, localized pain that often feels like the tooth is slightly elevated in its socket.
Periodontal disease causes inflammation and bone loss around the tooth, leading to pain upon chewing. As the disease progresses, the supporting bone is destroyed, and the periodontal ligaments weaken. This results in loose teeth that move or shift under the force of biting, making the tooth tender to pressure.
Pericoronitis is a localized infection that causes pain when the opposing tooth contacts swollen gum tissue. This condition typically occurs around a partially erupted wisdom tooth, where a flap of gum tissue becomes a trap for food debris and bacteria. The resulting inflammation and swelling make it difficult to bite down without hitting the tender, infected tissue, which can be acutely painful.
Jaw and Muscle-Related Causes
Not all biting pain originates in a specific tooth; it can also arise from issues related to the jaw joint and controlling muscles. Temporomandibular Joint (TMJ) disorders affect the sliding hinge that connects the jawbone to the skull, causing pain that is often exacerbated by chewing. Inflammation or misalignment of the joint can lead to an uneven distribution of forces during a bite, straining the surrounding muscles.
Chronic teeth grinding or clenching (bruxism) places immense stress on the jaw muscles. This muscle overuse causes fatigue and soreness, which manifests as pain when the muscles are activated to bite or chew. The constant tension can also lead to headaches and tenderness in the facial muscles, which may be mistakenly interpreted as a dental problem.
Referred pain from the maxillary sinuses can mimic a toothache, particularly in the upper back teeth. The roots of these teeth sit close to the floor of the maxillary sinus cavities. When a sinus infection or severe congestion causes fluid buildup, the resulting pressure can irritate the nerves in that area. This pain is often felt across several upper teeth on one side and may feel worse when bending over.
When to Seek Professional Care and What to Expect
Any persistent pain when biting down should prompt a visit to a dentist, as the issue is rarely transient. However, certain signs require immediate, urgent care to prevent serious complications. These emergency symptoms include rapidly spreading facial swelling, a high fever accompanying the pain, or difficulty swallowing or breathing. For less severe but persistent pain—such as discomfort lasting more than 48 hours or continuous sensitivity to hot or cold—a prompt appointment is necessary.
The diagnostic process begins with a thorough clinical examination and review of your symptoms. The dentist will use a variety of tools to pinpoint the source of the pain, often starting with dental X-rays to check for hidden decay, bone loss, or abscesses at the root tip. A bite test, often using a specialized device or cotton swab, reproduces the pain upon pressure or release, which is useful for diagnosing a cracked tooth. Additionally, a gentle tapping test on the tooth, known as percussion, can help determine if the inflammation has spread to the surrounding periodontal ligament.