The third molars, commonly known as wisdom teeth, are the final set of adult teeth to develop, typically emerging between the ages of 17 and 25. Many jaws lack sufficient space to accommodate these late arrivals, leading to impaction or misalignment. While the tooth itself rarely causes direct pain, complications from its eruption or impaction often manifest as recurring headaches. These headaches result from the mechanical pressure and infection the tooth can trigger in surrounding structures.
Understanding Referred Pain
A headache originating from a dental issue is often a case of referred pain, where discomfort is felt in a location different from the source of the injury. This process is mediated by the trigeminal nerve (Cranial Nerve V), the largest sensory nerve in the head, which provides sensation to the teeth, jaw, face, and large portions of the head.
The nerve has three major branches; the lower molars, including the wisdom teeth, are connected to the mandibular branch. When an impacted wisdom tooth irritates this branch, the brain can misinterpret the signal. This projects the pain to other areas supplied by the same nerve, such as the temples, forehead, or ear, causing the sensation of a headache rooted in the back of the jaw.
Headaches Caused by Mechanical Pressure
One common mechanism for wisdom tooth-related headaches is the physical pressure exerted by an impacted tooth. When a wisdom tooth grows at an angle or becomes trapped, it pushes against adjacent teeth or the surrounding jawbone. This constant pressure increases tension in the muscles of the jaw, face, and neck.
The resulting muscle strain can trigger a tension headache, often described as a dull ache or a feeling of a tight band around the head. This mechanical stress can also contribute to temporomandibular joint (TMJ) dysfunction. Misalignment of the bite places undue strain on the joint connecting the jaw to the skull, leading to headaches associated with pain near the ears, jaw stiffness, or a clicking sound.
Sinus Irritation
The roots of upper wisdom teeth are located close to the sinus cavities. When these upper molars become impacted or inflamed, the pressure can irritate the sinuses. This irritation leads to symptoms consistent with a sinus headache, such as facial pain, congestion, and pressure behind the eyes.
Headaches Caused by Infection and Inflammation
Headaches can also be a significant symptom when a wisdom tooth causes a localized infection. The most frequent infection associated with partially erupted wisdom teeth is pericoronitis, which is the inflammation of the gum flap covering the tooth. Food debris and bacteria easily become trapped under this flap, creating a breeding ground for infection.
The accumulation of bacteria triggers an inflammatory response, leading to swelling, localized pain, and sometimes pus discharge. This acute infection can spread, causing severe pain that radiates from the jaw to the ear and head. The accompanying swelling and stiffness in the jaw muscles, known as trismus, significantly contributes to tension-type headaches. In severe cases, the infection can cause systemic symptoms like fever and swollen lymph nodes, further exacerbating the headache experience.
Diagnosis and Professional Treatment
Determining if a headache is caused by a wisdom tooth requires a professional dental assessment. This begins with a visual inspection of the back molars and surrounding gum tissue, where the dentist looks for signs of impaction, inflammation, or infection. Diagnosis relies heavily on dental X-rays, which provide clear images of the tooth’s position, the degree of impaction, and any pressure exerted on adjacent structures.
For temporary relief, over-the-counter anti-inflammatory medications like ibuprofen can be effective. Rinsing the mouth with warm salt water also helps reduce gum inflammation and keeps the area clean. If the wisdom tooth is severely impacted, causing recurrent infections, or contributing to TMJ dysfunction, the definitive treatment is usually surgical extraction. Removal of the problematic tooth eliminates the source of pressure and inflammation, often resolving associated chronic headaches.