Tongue numbness following wisdom tooth extraction, medically termed paresthesia or dysesthesia, can be alarming. This altered sensation is a persistent sensory change, distinct from the temporary numbness caused by local anesthetic. While this complication is recognized in oral surgery, it affects only a small percentage of patients. Understanding the cause and prognosis of this unexpected symptom provides reassurance during recovery.
The Lingual Nerve and Surgical Proximity
Post-operative tongue numbness is directly linked to the anatomy of the lingual nerve. This nerve is a branch of the trigeminal system and provides general sensation and taste perception to the front two-thirds of the tongue. The lingual nerve courses along the inner side of the lower jawbone, often lying extremely close to the surgical site near the mandibular third molars.
Due to this proximity, the nerve is vulnerable to injury during extraction. Trauma usually involves compression, stretching, or contusion from instruments used to remove bone or retract tissue, rather than a clean severing. The surgical manipulation required to access a deeply impacted tooth can inadvertently transmit force to this nearby nerve bundle.
Grading the Severity of Nerve Disruption
The duration and nature of the numbness depend on the degree of physical trauma the nerve sustained, which is categorized into three levels of disruption. The mildest form of injury is similar to a nerve contusion, where the insulation layer of the nerve fiber is momentarily stunned or bruised. This results in a temporary interruption of the signal, but the nerve structure remains intact.
A moderate injury involves damage to the internal axon fibers, which carry the signals. However, the outer sheath remains whole, acting as a guide tube for slow but predictable regrowth of the damaged fibers. The most severe injury involves the complete disruption or severing of the entire nerve structure, including the outer sheath. This is the least common outcome and presents the most complex healing challenge, often requiring specialized intervention.
The Typical Recovery Timeline
Most cases of post-operative tongue numbness fall into the mild injury category and resolve spontaneously. For these temporary disruptions, sensation usually begins to return within a few days or weeks following surgery. Most patients who experience this complication have full resolution of symptoms within six weeks.
For moderate injuries, where internal fibers must regrow, the recovery process is much slower. Nerves regenerate at a biological rate of approximately one millimeter per day, meaning recovery can take several months. Patients may experience tingling or a “pins and needles” sensation as a sign that the nerve is actively healing and sensory function is returning.
If the altered sensation persists without improvement past the two-month mark, contact the oral surgeon for a formal evaluation. Persistent numbness lasting longer than six months, though rare, may indicate a more significant injury requiring further management. Treatment often starts with observation and supportive measures like B vitamin therapy. In the rare instance of a severe injury with no recovery, microsurgical nerve repair may be considered after a substantial period of observation.