After a wisdom tooth removal, an implant or jaw surgery, some patients notice that part of the lower lip, chin or tongue still feels numb, tingly or different once the anesthetic should have worn off. The question they ask, and the one their dentist often asks with them, is whether to wait or to have it looked at. This article explains how we think about that decision. The clinical details are also on our Trigeminal Nerve Repair page.
Which nerves are involved
Two branches of the trigeminal nerve carry sensation in the lower jaw:
- The inferior alveolar nerve (IAN) runs through a bony canal in the lower jaw and supplies the lower teeth, lower lip and chin. Damage or compression causes numbness or altered sensation of the lip and chin on that side.
- The lingual nerve runs just inside the lower jaw and provides sensation and taste to the side of the tongue and the inner gums. Injury may cause numbness, altered taste, burning or hypersensitivity, and can affect speech and eating.
These injuries most often follow third molar surgery, implant placement or jaw surgery. Persistent numbness is listed among the rarer risks of wisdom tooth removal and, uncommonly, of dental implants and tooth extractions.
Does it get better on its own?
Often, yes. Not every nerve injury requires surgery. When the nerve has been bruised or stretched, sensation frequently returns over weeks to months without treatment.
Surgery is considered when the nerve is torn, severely compressed or blocked by scar tissue (a neuroma), and objective testing shows no recovery. The difficulty is that these situations can feel the same to the patient in the first weeks. Testing, rather than waiting alone, is what tells them apart.
Why the timing matters
Timing has a strong influence on the outcome of nerve repair. The optimal window is typically within 3 to 6 months of the injury, with an upper threshold of around 9 to 12 months. Beyond one year, the likelihood of success falls significantly.
For that reason, if numbness persists for more than a few weeks after an oral procedure, a neurosensory evaluation is advisable. An evaluation does not commit anyone to surgery. It establishes a baseline, so that recovery, or the lack of it, can be measured rather than guessed at while the window is still open.
What happens at the evaluation
- Objective neurosensory testing: light touch, directional brush stroke, two-point discrimination and temperature testing, used to grade the injury.
- 3D CBCT imaging and virtual planning where needed, to identify the site of injury, for example an implant entering the mandibular canal or a plate compressing the nerve.
- Insurance coordination for coding and pre-authorization.
It helps to bring the date of the original procedure, any imaging and the name of the treating clinician.
If surgery is recommended
Trigeminal nerve repair is a microsurgical procedure. Depending on what the evaluation shows, it may involve:
- Decompression: removal of bone fragments, plates or implants pressing on an intact nerve.
- Direct neurorrhaphy: trimming and tension-free reconnection of the nerve ends with sutures finer than a human hair.
- Nerve grafting: bridging a missing or scarred segment with a processed nerve allograft.
The operation is performed under general anesthesia, entirely through incisions inside the mouth, so there are no facial scars. The lingual nerve is reached through the tissues inside the mouth. Because the inferior alveolar nerve lies within the bone, a sagittal split of the lower jaw is sometimes used to open the canal and reach the nerve directly; the bone is then secured with low-profile titanium screws. The jaws are not wired shut, including when a sagittal split is used for access.
What recovery of sensation looks like
Nerves regenerate slowly, at roughly 1 mm per day, so sensory return is gradual over 3 to 12 months. Tingling or "electric" sensations during healing are often a sign of regrowth rather than a setback.
For referring dentists and surgeons
Persistent numbness after third molar or implant surgery is ideally referred within 3 to 6 months. Records and imaging (CBCT or panoramic, in DICOM or image format) can be sent through our Referring Doctors page, and our office will coordinate the evaluation with you. Both of our surgeons, Dr. Andrei Marechek and Dr. Youn Sagong, evaluate and treat trigeminal nerve injuries.
Related pages
This article is general information, not medical advice. A consultation is the place to talk about your own situation: call (949) 771-2121 or request a consultation.