A bad dental crown can cause chronic or recurring headaches and facial pain. This connection is often overlooked because the pain is felt far from the tooth itself. When a dental restoration, like a crown, is incorrectly placed or begins to fail, it introduces a constant disturbance to the delicate alignment of the jaw. This disruption triggers a complex chain reaction involving nerves and muscles, resulting in pain perceived in the head, neck, or face.
The Mechanism of Referred Pain
Pain signals from the mouth, teeth, and jaw are transmitted through the trigeminal nerve, the body’s largest cranial nerve. This nerve handles sensory input from the face and motor functions like chewing. Irritation or strain in one branch of this system, such as a tooth or the surrounding jaw joint, can cause the brain to misinterpret the source of the pain.
This phenomenon is known as referred pain, where the discomfort is felt in a distant location along the same nerve pathway. A problem with a molar, for example, can manifest as a persistent, dull ache in the temple, the forehead, or around the ear. The intense, prolonged muscle strain caused by a bite imbalance is a common trigger for this type of headache.
A poorly fitting crown can place excessive and uneven pressure on the temporomandibular joint (TMJ), the hinge connecting the jaw to the skull. The surrounding muscles are forced to work harder to compensate for the imbalance. This constant overactivity leads to muscle fatigue and spasm, which are the physical origins of tension-type headaches that radiate across the head.
Specific Crown Problems That Trigger Headaches
The most frequent crown-related cause of headaches is malocclusion, or an improper bite, where the crown is slightly too high. Even a fraction of a millimeter difference in height can prevent other teeth from meeting correctly, disrupting the jaw’s resting position. The jaw muscles react to this premature contact by constantly straining to find a comfortable closing position, leading to chronic muscle pain and subsequent headaches.
Another source of headache is hidden decay or infection underneath the crown. If the crown seal fails, bacteria can leak in and cause new decay or inflammation of the tooth’s pulp. This internal swelling and pressure irritates the nerve, causing intense, throbbing pain often perceived as a severe head or facial ache. This pain frequently signals that a root canal procedure may be necessary to resolve the infection.
The physical fit of the crown’s edge, known as the margin, can also contribute to chronic discomfort. If the margin is ill-fitting, it can trap food debris and irritate the surrounding gum tissue, leading to localized inflammation. The chronic nature of this inflammation can contribute to generalized facial discomfort and increased sensitivity in the trigeminal nerve system.
Dental Diagnosis and Resolution
The process of diagnosing a crown-related headache begins with a comprehensive dental examination, including a thorough review of the patient’s bite. Dentists often use articulating paper, a thin piece of colored paper, to identify points of premature or excessive contact on the crown when the patient bites down. This analysis reveals the precise areas of malocclusion that are throwing the jaw out of balance.
Diagnostic imaging, specifically dental X-rays, is essential to determine if infection or decay is hidden beneath the crown. These images allow the dentist to check the integrity of the underlying tooth structure and the health of the supporting bone. The dentist also physically examines the jaw muscles and TMJ, checking for tenderness, clicking sounds, or restricted movement, which are common signs of strain.
Once a high spot is identified, the most common resolution is a simple occlusal adjustment, which involves carefully polishing the crown to correct the contour. If decay or infection is present, the crown may need removal for a root canal treatment or other restorative procedures before a new crown is placed. When the crown is severely ill-fitting or the bite cannot be corrected with adjustment, replacing the entire crown to ensure a proper fit and seal is the definitive course of action.