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Based on the informed provided the numbness and pain on right side of lip and chin you have been experiencing could be due to salivary gland
stone or sialolithia sis( Parotid Gland
The numbness is suggestive of compression of the stone on the facial nerve
( facial nerve passes through parotid and gives off 5 terminal branches).
Get Sialography or ultrasound done to rule out salivary gland stone.
Please see a surgeon immediately and get the stone removed ( if the stone is found on sialographyor ultrasound). Because if left untreated, it might leads to weakness or paralysis of facial muscles
. Meanwhile using Vitamin B12
containing preparations should help you to some extent.
Wish you a speedy recovery.