Minimally invasive tooth extraction is to remove the affected teeth with minimal trauma, and there are several reasons for injury to the nerve: 1, anatomical factors, especially in the extraction of mandibular blocked teeth, the root of the blocked tooth itself and the neural tube has a very close relationship with the neural tube, part of the direct insertion into the neural tube inside the process of extracting the tooth out of the nerve, how much damage to the nerve will be 2, the teeth can not be erupted completely in the process of growth, the root of the tooth will be produced by expansion or hyperplasia, increasing the difficulty of extraction. Enlargement increases the difficulty of extraction, and in the process of loosening the tooth root, there is a possibility of compression of the neural tube, resulting in nerve damage, so minimally invasive tooth extraction can not be done completely without nerve damage.