TMJ and swimming

A dentist I am seeing who specializes in TMJ is advising that while going through nine months of treatment for TMJ I need to stop swimming laps. This is not an option for me as at my age swimming controls many other conditions so I do not take meds and running or biking is not an option.  Plus it is good for emotional and mental stress and for socialization.. What experience do others have with this and were you able to continue swimming through treatments? (Treatment means for nine months a tight orthotic on lower jaw to realign jaw and only to be removed to brush teeth.