I wore a night guard for one night and woke up with my front teeth moved and jaw changed, the mandible is rotating towards my head, will they return?

Maybe Not: Without knowing what kind of night guard or the specific reason for it, its hard to say for sure. Many times when the teeth aren't allowed to contact, the jaw joint(s) finds a new my comfortable "home", which is not always where the teeth tell it to close. Further treatment may be necessary, but i would advise your dentist and probably give it a little more time. The guard might just not fit, too.

Teeth shouldn't move: There are many types of night guards. A night guard should protect your teeth from damage from grinding and clenching however your teeth should definitely not move! call your dentist and request a consultation. It sounds as though the night guard was not made and/or fitted properly.

Yes: Are your teeth sore? If so perhaps your nightguard is attempting to move them and not fitting correctly. If not, it is probably your jaw muscles that have caused your jaw to move. As the day goes on, your muscles will relax and return the jaws back to normal. Either way, have your dentist check your nightguard!

Fit?: Make sure that your night guard fits correctly, consult a dentist.

Needs adjustment: Night guards often require multiple adjustments. Call your Dntist now.