The numbness of half of the tongue after wisdom tooth extraction for more than a year may be caused by the damage of mandibular nerve and lingual nerve caused by tooth extraction. 1. Damage to the mandibular nerve: the patient may be wisdom teeth extraction mandibular nerve damage caused by the numbness of the tongue, can be taken under the guidance of the doctor to alleviate the treatment of nutritive drugs, such as methylcobalamin, vitamin B ₁, vitamin B ₁ ₂, and so on. 2. Damage to the lingual nerve: the patient may have numbness of the tongue caused by damage to the lingual nerve when wisdom teeth are extracted, and can use methylcobalamin, vitamin B₁, rat nerve growth factor and other drugs under the guidance of the doctor to alleviate the treatment. It is recommended that patients should maintain a light diet and pay attention to oral hygiene during the recovery process.