Is it a good or a bad sign if your lip and chin twitch during healing of Bell's palsy?

Bell's palsy. It depends on how complete the paralysis to begin with and how far into the healing process you are. Twitching indicates nerve regeneration in the paralyzed regions, but can be permanent in a minority of cases. Healing usually happens starting at 3 weeks and ending up to 6 months later. Most people heal completely. Make sure you protect your eye from drying with natural tears and lubricants.