Back molar pain is a common symptom that can significantly impact daily life. This discomfort, localized in the back of the mouth, can range from a dull ache to sharp, intense throbbing. Understanding its potential sources is a helpful step in addressing the discomfort.
Problems with the Tooth Itself
Pain originating directly from the molar structure often points to internal issues.
Tooth decay begins when bacteria in the mouth produce acids that erode the tooth’s enamel. As decay progresses into the dentin, sensitivity to hot, cold, or sweet stimuli can occur. If decay reaches the innermost pulp chamber, it can lead to constant pain.
A cracked or fractured tooth is another direct cause of molar pain. These cracks can be microscopic and difficult to detect, often extending from the chewing surface into the tooth structure. Pain typically manifests as a sharp, sudden sensation when biting down or when the tooth is exposed to temperature changes, as the crack widens under pressure and irritates the underlying pulp. Over time, these cracks can deepen, potentially leading to more severe pulp involvement.
Pulpitis, inflammation of the dental pulp, occurs when bacteria from deep decay or trauma reach the pulp chamber. This inflammation can be reversible, leading to temporary sensitivity if the cause is removed. However, severe or prolonged infection can lead to irreversible pulpitis, causing persistent, spontaneous pain and often requiring root canal therapy or extraction. The pressure from swelling within the confined pulp chamber contributes to intense discomfort.
When a bacterial infection within the tooth’s pulp spreads beyond the root tip, a dental abscess can form. This pus-filled pocket develops at the root of the tooth or in the surrounding bone. Symptoms include severe, throbbing pain, gum or facial swelling, tenderness when chewing, and sometimes fever or swollen lymph nodes. The pressure from accumulating pus causes significant pain.
Issues with Gums and Surrounding Structures
Beyond the tooth itself, the surrounding gum tissues and supporting structures can also be sources of molar pain.
Gum disease involves inflammation and infection of the gums and the bone that supports the teeth. Early stages, known as gingivitis, cause red, swollen, and bleeding gums. As the condition progresses to periodontitis, the infection damages bone and connective tissues, forming pockets around the teeth and potentially causing molars to become loose and painful.
Wisdom teeth frequently cause pain due to their late eruption and limited jaw space. When impacted, meaning they do not fully emerge or grow at an awkward angle, they can put pressure on adjacent molars. Impaction can also trap food and bacteria, leading to infections like pericoronitis, an inflammation of the gum tissue surrounding the partially erupted tooth. This condition causes localized pain, swelling, and difficulty opening the mouth.
Molar sensitivity can arise after recent dental work, such as fillings or crowns. This post-procedure sensitivity is typically temporary, lasting from a few days to a few weeks. It occurs as the tooth’s pulp reacts to drilling or new restorative material. The discomfort usually subsides as the pulp heals and adjusts.
Pain Originating Elsewhere
Molar pain does not always stem directly from the tooth or gums; sometimes, it is referred pain from other areas.
Sinusitis, an inflammation or infection of the maxillary sinuses, can mimic upper molar pain. These air-filled cavities are located just above the roots of the upper back teeth. When congested or infected, the pressure can be felt in the upper molars, often worsening when bending over or jumping.
Disorders of the temporomandibular joint (TMJ), which connects the jawbone to the skull, can also cause referred pain to the molars. Issues with this joint or surrounding muscles can lead to pain that radiates to the jaw, ear, and back teeth. This discomfort might worsen with chewing, speaking, or wide mouth opening, presenting as a dull ache in the molar region.
Bruxism, the involuntary grinding or clenching of teeth, particularly during sleep, puts excessive force on the molars. This chronic pressure can lead to tooth sensitivity, jaw muscle soreness, and a dull ache in the back teeth. Over time, bruxism can also cause wear on tooth surfaces, contributing to further discomfort and dental damage.