An overbite, a form of malocclusion, occurs when the upper front teeth overlap the lower front teeth by an excessive amount. While a slight overlap is considered normal and healthy, when the vertical overlap is too great—often described as a deep bite—it can become problematic for the jaw’s function. This misalignment disrupts the harmonious relationship between the dental arches, forcing the jaw to function outside of its natural, relaxed position. The mechanical stress resulting from this uneven bite causes muscle strain and joint dysfunction, making a misaligned bite a contributing factor to headaches.
How Jaw Misalignment Creates Tension
The connection between an overbite and head pain begins with the muscles responsible for chewing and jaw movement, known as the muscles of mastication. When the upper and lower teeth do not meet correctly, the jaw is unable to find a comfortable resting state. This forces the masticatory muscles to work harder and remain perpetually tense in an unconscious attempt to stabilize the jaw joint and align the teeth during functions like chewing and swallowing.
Specifically, the large temporalis muscles on the side of the head and the masseter muscles at the angle of the jaw become overworked. The pterygoid muscles, located deeper inside the face, are also affected as they try to reposition the lower jaw to compensate for the overbite. This constant, excessive muscular effort leads to fatigue and chronic tension, which can radiate pain away from the jaw area.
This radiating pain is an example of referred pain. The pain signals from the strained jaw muscles and joint travel along the trigeminal nerve (Cranial Nerve V). The trigeminal nerve is the primary sensory pathway for the face, and its branches innervate the jaw joint, the muscles of mastication, and other parts of the head.
Irritation along this nerve pathway, caused by the chronic strain from the overbite, transmits pain into the head and face. This often manifests as a tension-type headache or pain around the temples. The severity of the malocclusion, especially a deep overbite, increases the likelihood of this muscle strain and subsequent nerve irritation.
Understanding Temporomandibular Disorders (TMD)
The physical and muscular stress caused by a significant overbite can lead to a condition known as Temporomandibular Disorder (TMD). TMD is a broad term encompassing problems with the temporomandibular joint (TMJ), which acts as a hinge connecting the jawbone to the skull, and the surrounding muscles. An overbite can disrupt the mechanics of the joint by causing an uneven distribution of force, leading to inflammation and muscle strain.
While not every person with an overbite will develop TMD, the structural imbalance places the joint under undue pressure, which can trigger the disorder. The resulting dysfunction can manifest through a variety of symptoms beyond headaches. Common indicators include a clicking, popping, or grinding sound (crepitus) in the jaw joint when the mouth is opened or closed, which suggests the protective disc within the joint may be displaced.
Patients with TMD often experience localized pain or tenderness in the jaw joint area, especially near the ear. Other associated symptoms include limited jaw movement, facial tenderness, earaches without infection, and occasionally a feeling of fullness in the ear.
The headaches linked to TMD frequently mimic other common types of pain, such as tension headaches that wrap around the head or migraine-like pain. The pain is typically felt in the temples, forehead, or behind the eyes, and can be chronic. A proper differential diagnosis is necessary to confirm that the bite issue is indeed the root cause, rather than other factors like stress or neurological conditions.
Dental and Medical Treatment Pathways
Once a headache is diagnosed as being caused by TMD secondary to an overbite, treatment focuses on reducing the strain and correcting the underlying misalignment.
Orthodontic Correction
Orthodontic Correction aims to permanently fix the bite. This involves using appliances like braces or clear aligners to gradually move the teeth and jaw into their correct, stable positions. This process eliminates the source of muscle compensation.
Oral Appliances
Another common pathway involves the use of Oral Appliances, such as stabilization splints or custom-fitted night guards. These devices are worn over the teeth to hold the jaw in a relaxed position, which helps reduce muscle strain and protects the teeth from damaging forces like clenching or grinding (bruxism). The initial treatment often involves an appliance to stabilize the joint and resolve the immediate pain.
Adjunctive Therapies
Adjunctive Therapies are often used alongside dental correction to manage pain and restore function. This can include physical therapy, which uses exercises to strengthen and stretch the jaw muscles, and techniques like moist heat application or massage. Other medical treatments may involve trigger point injections into the overactive muscles or the use of medications to manage inflammation and chronic pain.