13mth son born profoundly deaf r ear, never produces nasal discharge, have to use saline drops to moisten, is this problem caused by deafness?

Deafness: Deafness it self is not responsible for his dry nose. If he does not have a stuffed nose, I do not think you need to give the saline drops. We usually recommend it to moisten the dry secretions to be able to get them out and clear the nose.

Unlikely: I am not sure if you are saying your baby is congested and doesn't make a lot of nasal drainage or if he breathes well through the nose. Saline is a great thing to use in drop form to help a baby breathe through the nose if congested. Some associated problems with the back of the nose can be present in some deaf kids ("choanal atresia") that could be considered if it is always blocked on 1 side.