The ability to close your mouth and feel your back teeth (molars) meet is essential for chewing and speaking, a process known as occlusion. When you cannot fully bite down, or experience pain upon closing your jaw, it signals a disruption in your bite system. This sensation of premature contact, where one tooth hits before the others, indicates a problem with jaw alignment or a localized issue with a specific tooth. This common symptom requires professional evaluation to determine the underlying cause and prevent further complications.
Mechanical Interference from Dental Work
A common reason for a sudden change in bite is the introduction of a new dental restoration, such as a filling, crown, or onlay. If the material is slightly “high,” it extends too far above the tooth’s natural chewing surface. This small elevation causes the opposing tooth to strike the restoration prematurely, preventing the other back teeth from meeting correctly.
The jaw muscles instinctively shift or avoid biting down fully to protect the tooth from excessive pressure. This premature contact can lead to discomfort, muscle soreness, and a feeling of an imbalanced bite. Fortunately, this issue is straightforward to resolve: a dentist uses articulating paper to identify the high spot and adjusts the occlusion by polishing the restoration down slightly. This quick procedure usually restores the bite to its natural, comfortable state.
Causes Related to Tooth Pain and Inflammation
When a bite change is accompanied by pain, it often signals a problem within the tooth’s structure or supporting tissues. Deep tooth decay (caries) can cause pulpitis, which is inflammation of the dental pulp—the nerve and blood vessel center of the tooth. Pain upon pressure, such as biting down, is a classic symptom of this internal inflammation.
Another cause is cracked tooth syndrome, where a fracture line extends into the dentin, causing sharp, momentary pain during chewing forces. If an infection develops at the root tip, it forms a periapical abscess. The resulting inflammatory pressure can slightly extrude the tooth from its socket. This subtle elevation makes the infected tooth feel higher than the others, causing it to strike first and leading to immediate, intense pain when biting. Localized gum inflammation (periodontitis) can also cause the ligament surrounding a molar to swell, making the tooth sensitive to pressure and movement.
Muscle and Jaw Joint Issues
When the problem is not isolated to a single tooth, the cause may lie in the complex mechanics of the jaw and its associated muscles. Temporomandibular disorders (TMDs) involve the temporomandibular joints (TMJ) and the muscles that control jaw movement. Misalignment or dysfunction in these joints can cause the mandible, or lower jaw, to shift, leading to an uneven bite and difficulty achieving full closure.
Bruxism, the habit of clenching or grinding teeth, often during sleep, can lead to muscle fatigue and soreness in the muscles of mastication. This muscle tension can alter the resting position and movement of the jaw, resulting in a feeling of a misaligned or uncomfortable bite upon waking. TMDs can also present with symptoms beyond bite issues, such as clicking or popping sounds in the joint, generalized facial or ear pain, and headaches. Addressing these issues often requires managing muscle activity and restoring the correct functional relationship between the jaw and the joint.
Immediate Steps and Professional Consultation
If you are experiencing difficulty biting down, a few simple self-management steps can temporarily relieve discomfort before your appointment. Switching to a soft food diet reduces the need to apply heavy chewing forces on the back teeth, which prevents further irritation to an inflamed tooth or joint. Over-the-counter nonsteroidal anti-inflammatory drugs (NSAIDs) can help manage pain and reduce localized inflammation. Applying a cold pack to the outside of the jaw for brief intervals may also help reduce swelling and muscle soreness.
Avoid attempting to self-diagnose or adjust your bite by chewing on the affected side, as this action can worsen the underlying condition. You should seek emergency care if the pain is accompanied by signs of a spreading infection, such as:
- Severe swelling of the face or neck.
- Difficulty breathing or swallowing.
- A high fever.
For all other cases, scheduling a prompt visit with a dental professional is the necessary next step for a definitive diagnosis and targeted treatment plan.