Why is my mouth and tongue having numbness?

Need exam: I can't tell you why you are having numbness in your mouth. There are many possible reasons for this. This best thing to do is to sea dentist or oral surgeon for an exam.

Is the: Numbness secondary to a dental procedure you have recently had or is it numb for no reason ? Would need to know in order to answer. Hope this helps.

Personal evaluation: A numb feeling in the mouth or tongue could have many possible causes, such as but not limited to an early sign of aphthous stomatitis, a dry mouth (xerostomia), from medications, hormonal changes, certain medical conditions, or allergies. See your dentist who may need to refer you to your physician for an evaluation.