You seem to be suffering from a pattern of hair loss known as alopecia areata
. It is an auto immune disease characterised by coin shaped round patches of hair loss. It has a remitting and relapsing pattern.
The treatment involves intralesional injections of steroid, application of minoxidil, salicylic acid
, topical steroids, tretinoin, dithranol is effective too. Sometimes if the disease is progressive then oral steroids and an immunomodulator like levamisole
is prescribed too. As it is an autoimmune disease
we can stop the progression of existing lesion and help in hair regrowth however no medicine intake can prevent its further occurence or cure it completely.
As far as your molar tooth decay is concerned, you may consult a dentist
and get it extracted.
Hope that helped