1) This doesn't exclude the possibility of those extracted teeth were bad and needed extraction. Looking at his picture, he has severe periodontal disease.

2) Trigeminal (Canial nerve V) Neuralagia causes are varied such as compression of nerve root, inflammation of nerve root ie. MS, tumor and etc ... It usually affect one side of the face, though bilaterally is rare. Treatment is usually with an anti-seizure medication ie. carbamazepine, but pt. of Asian ancestry need to be tested for Stevens-Johnson Syndrome and Toxic Epidermal Necrolysis.

3) A more detail history was properly not done by any of the involved physicians (MD & DDS)