“Does CPD relieve facial pain?”

Pain isolated to the chin is a rare matter, particularly if it crosses the middle of your chin. As for the medication, I believe you are referring to CBD (cannabidiol), a non-psychoactive phytocannabinoid from the cannabis plant. There is certainly many people who are using these products for pain relief, although the products are not regulated by the FDA and as such purity and potency, as well as general safety, are really unknown from one product to the next. I always like to come to a diagnosis before recommending any treatment, surgical or medical. I suggest you keep looking for a diagnosis, and you may find it will take seeing additional doctors (other oral surgeons, dentists, perhaps a neurologist) to do so.