Hello, welcome to HCM forum for sharing your concern. It's not welcome, but is also not unusual that the nerve supplying sensation to the tooth, lip, chin could be injured during injection near the nerve or during extraction of
impacted tooth. Instead of injecting near the nerve, the needle may injure the nerve, as it is blind procedure, and the
dentist has to depend upon some external landmark in the oral cavity to reach near the nerve. Secondly the nerve can also be injured during extraction as the nerve passes just below the impacted tooth. This kind of
nerve injury will lead to the complications same as you are suffering, called
paresthesia. But good news is that this kind of nerve injury mostly heals within 2 weeks to 4 months depending upon the degree of injury. Permanent loss of sensation occurs when there is most of the nerve diameter is injured and that is very, very UNCOMMON. Wait for 2-3 weeks, if you are not feeling any improvement, consult your oral surgeon. He will prescribe some medicine which can aid in nerve healing. Careful about not to bite your numb lips. Hope, you will get well soon.