Strange anesthetic effect, moving across face

I recently had some minor fillings done on both sides of my mouth. On the right side, I was given the usual injected anesthetic in top and bottom, numbing my whole right side but not paralyzing, which wore off in a couple hours.

However, on the left side, I was given what he called a "longer lasting" anesthetic. At first it felt like common anesthetic, but with less tingling and a stronger topical effect under the teeth (not in the face). It was injected to only the top side. However, I couldn't move my left facial muscles voluntarily. Around 7 hours after the fillings, long after the right side common anesthetic wore off, the left side teeth got feeling back, but the numbness increased in the left side of my face.

At around 12 hours after the surgery, the numbness in the left side of the face, as well as muscle paralysis, wore off. However, at this time, my right facial muscles started getting numb, but remained movable. After about an hour, the common numbing effect of the right had returned at about half effect. This effect moved down into the jaw, teeth, and cheek where I was originally numb on the right side, and now is staying at about 33% strength in the teeth, and probably 20% in the face.

There was never any visual appearance changes, itching, or other discomfort.

Two things I'm wondering.
1. What is the most likely cause of this phenomenon, if it goes away shortly?
2. What should I do if I still have mild numbness in the right side after 24 hours, or it moves again?