Left side numb left side of mouth and tongue numb?

Spontaneously ?: Left side of your body? Just your face? Is this after a dental procedure or an extraction? Have you seen a dentist? You need to be evaluated immediately by a dentist for an infection if it is just your mouth and tongue, and immediatelt by an er physician if your body is numb.

Its called : Paresthesia. Is this something that just happened from earlier today? Did you have an extraction on the lower left? In any event, if this numbness persists more than a day, you should inform your treating dentist. Typical anesthetics last about 4 hours; some (marcaine) can even last 8-12 hours. Hope this helps.