I usually advise my patients to have fixed retainers for both upper and lower front teeth after braces.
If you are completely reliant on removable retainers and you don't wear those enough, the teeth can start drifting.
Fixed retainers make it easier for patients to maintain the results of their braces, but fixed retainers can fail as well. Regular dental checkups can detect if a fixed retainer is damaged and needs replacing.
If you have been able to tolerate your lower fixed retainer, the upper should not be very problematic. There are different materials available for fixed retainers, and some may be more comfortable than others.
Your dentist will be able to advise you on which materials are suitable.
You may need to be more careful when eating very hard foods (nuts, for example) with a fixed retainer on the upper since these foods may cause the retainer wire to snap, or the retainer to become detached from the teeth.
I would still advise clear retainers in addition to the fixed retainers since patients may sometimes be unaware when a fixed retainer is damaged and not holding the teeth any longer. The clear retainers are the failsafe backup for the fixed retainers.
Clear removable retainers can also warp and stretch out over time, and these should be checked every year and replaced, if necessary. Hope this helps!
