Pain originating from the gums in the back of the mouth can be particularly unsettling because the area is difficult to inspect visually. This discomfort frequently signals an issue specific to the posterior region of the jawline. While the source of the pain can vary widely, the causes generally relate to the unique anatomy and function of the back molars.
Primary Cause: Third Molar Issues
The most frequent source of pain in the far back of the jaw involves the third molars, commonly known as wisdom teeth. These teeth often attempt to emerge into a jawline that lacks sufficient space, leading to a condition called impaction. As the tooth pushes against the adjacent molar or the surrounding bone, it creates a deep, aching pressure sensation. This mechanical force generates inflammation in the gum tissue directly overlying the erupting tooth, sometimes causing referred pain toward the ear.
When a third molar is fully impacted, meaning it is completely enclosed within the bone or gum tissue, the pain often results from the pressure it exerts on the nerve or bone. This pressure can trigger a response in the surrounding periodontal ligament, which is rich in sensory nerves. Furthermore, the body’s attempt to remodel the bone to accommodate the erupting tooth is an inflammatory process that contributes significantly to the chronic discomfort experienced.
A distinct issue associated with partially erupted wisdom teeth is pericoronitis, which is an infection and inflammation of the soft tissue flap that covers the crown of the molar. This gum flap is technically known as the operculum, and the space between it and the tooth surface becomes a perfect niche for bacteria and food debris to collect. Since proper cleaning is almost impossible in this confined space, the bacterial population quickly multiplies, leading to localized infection.
Pericoronitis is classified based on its severity, ranging from chronic, mild inflammation to acute infection. In the acute form, the infection can cause significant swelling, tenderness, and sometimes a foul taste due to pus formation. The chronic version involves persistent, low-grade inflammation that may flare up intermittently. A partially erupted tooth presents the additional risk of infection because the oral cavity is now open to the surrounding tissues.
Localized Gum Disease and Abscesses
Pain in the back gums can also stem from established bacterial infections affecting the posterior molars, independent of wisdom tooth issues. The far reaches of the mouth are often neglected during routine brushing and flossing, leading to significant plaque and tartar buildup. This accumulation can initiate gingivitis, a condition marked by inflamed, reddened, and easily bleeding gum tissue.
If gingivitis is left untreated, the inflammation can progress to periodontitis, which involves the destruction of the bone and ligaments supporting the teeth. Deep periodontal pockets form between the gum and the tooth root, which harbor disease-causing bacteria. The infection in these pockets can generate chronic, localized pain and sensitivity, sometimes causing the tooth to feel loose.
Periodontal Abscess
A periodontal abscess develops within the gum tissue itself, usually as a result of a deep periodontal pocket becoming blocked and trapping the bacterial infection. This causes a painful, rapidly expanding pocket of pus along the side of a tooth that is usually still alive. The swelling associated with this type of infection is usually confined to the gum line and feels intensely tender to the touch.
Periapical Abscess
A periapical abscess forms at the very tip of the tooth root, often due to severe decay or trauma that allows bacteria to enter the inner pulp of the tooth. This infection travels down the root canal and exits into the surrounding jawbone. The resulting pressure from the expanding infection within the bone causes the characteristic throbbing pain. While originating inside the tooth, the resulting pressure and inflammation can manifest as intense gum pain in the immediate area.
Physical Irritation and Dental Trauma
Not all posterior gum pain is caused by bacteria or tooth eruption; sometimes, it results from direct mechanical injury or trauma. Aggressive horizontal brushing, particularly in the hard-to-reach back areas, can cause the gum tissue to recede or become inflamed. Similarly, the sharp edges of hard foods, such as chips or popcorn hulls, can wedge forcefully into the gumline, leading to a puncture wound and subsequent irritation.
Thermal injuries, like accidental burns from very hot liquids or foods, can cause temporary but significant pain and blistering on the delicate posterior gum tissue. Furthermore, irritation can arise from dental restorations that do not fit correctly. A crown or filling with an overhanging margin can constantly press against the gum, creating a chronic source of inflammation and tenderness.
Immediate Steps and Professional Consultation
Individuals experiencing posterior gum pain can take immediate steps to manage discomfort while awaiting a dental examination.
Home Care Measures
Rinsing the mouth several times a day with a warm saltwater solution can help soothe inflamed tissue and flush out trapped debris. Over-the-counter pain relievers, such as ibuprofen, are effective for managing both pain and associated inflammation. Applying a cold compress to the outside of the cheek near the painful area can help reduce localized swelling. It is important to continue gentle brushing and flossing around the affected area to prevent further plaque accumulation, but avoid direct, aggressive manipulation of the painful spot. If home care measures do not provide substantial relief within 24 to 48 hours, professional diagnosis and intervention are required.
When to Seek Immediate Care
Certain symptoms require immediate professional attention beyond routine dental scheduling. If the swelling extends noticeably into the face, cheek, or neck, or if it causes difficulty in swallowing or breathing, this indicates a potentially spreading infection. Prompt evaluation is necessary to prevent serious complications if you experience any of the following:
- Swelling that extends noticeably into the face, cheek, or neck.
- Difficulty in swallowing or breathing.
- The presence of a fever.
- Severe bleeding.
- Pain so intense that it prevents sleep.