I can only speak for myself because like MS, TN is probably different for everybody.
I’ve had TN for more than 15 years. It was completely controlled by medication for a long time. For all I know it could have gone away but I wasn’t willing to stop the drugs to find out. Then it started to come back, twinges and then pain, perhaps not as bad as at first but bad enough. My GP increased my medication until I was taking a cocktail of gabapentin, tegretol and amytripteline. OK the pain had gone but I was a living zombie. One doc said I was taking enough to drop a horse LOL.
My neuro referred me to a surgeon and I had a procedure called thermocoagulation. They insert a needle into your cheek (yeuk) and zap the nerve. This procedure leaves numbness in your face and isn’t permanent so it’s not for everybody. My objective was to be able to reduce my medication which I did until I was just taking Tegretol. It’s been 18 months now and the pain is once more rearing it’s head. I have increased my Tegretol dosage but it’s likely that I will have to have the thermocoagulation done again.