Is it ok to wear retainers if you have bruxism?

Bruxism: Yes. Unfortnately regular retainers won't protect the teeth from the detremental effects of the grinding. Most patients that have spent $$ on their teeth would like to preserve them for many years. Retainer + bite guard or combo device like oral appliance may be more useful. Talk with orthodontist or sleep dentist.

Wearing Retainers: Yes, wearing retainers can be helpful. There are a number of different types though, some types will protect your teeth, but are not really helpful for your jaw, tmj's or facial muscles. Some retainers will actually make your jaws more tired or your tmj's feel worse. In that situation you will need a very specific guard that can hold your teeth in place, and also posture your muscles to relax.

Absolutely!: I would discuss this with your orthodontist or family dentist. There are types of retainers that can be fabricated that will help minimize the effects of clenching and grinding on the chewing system in addition to keeping your teeth straight!

Consider: Consider occlusal orthotic (night guard) rather than retainers. That way you can grind the plastic orthotic rather than your teeth. See an Orthodontist to see if your bruxism is malocclusion induced.

The ultimate combo: During the day retainers (upper and lower) only. During the night a full-arch occlusal stabilization appliance (night guard) opposed orthodontic retainer. Remember: we don’t cure bruxism with splints, although they help. Consult with your orthodontist for more information and options.

See orthodontist: Complex question. You didn't mention if your retainers help or worsen the bruxism. Your orthodontist (hopefully a board certified orthodontist) should have already addressed this with you. See him/her, you could possibly have a combination appliance to manage both issues. See a TMJ expert if necessary to coordinate treatment with orthodontist.