The muscle part is quite accurate.The frenum can play an important role in de-rotation or rather re-rotation of the front teeth.So youmight want to get that checked out.
Another thing is the Supra-crestal fibres,or the fibres above the crest of the bone.When a rotated tooth is de-rotated using braces,the fibres change direction too.What happens in such cases is that the fibres try to go back into their original position resulting in re-rotation of the teeth.So for some patients a surgery called as Supra-crestal fibrectomy is performed,to pervent the fibres from pulling the teeth back.
Permanent retainers are also an option,and they don't look that bad as they are permanently bonded to the front teeth on the inner aspect.You just got to keep your teeth clean.
If you have just had braces,then I would not advise bleaching.If the adhesive used for the brackets is still on the teeth giving them a yellow appearance,just get a thorough cleaning done from your orthodontist or dentist or their hygienist and the yellowness will be taken care of.
Bleaching can lead to sensitivity specially if done just after ortho treatment.So I would suggest that your avoid that for some time.
A semi-bleaching toothpaste like Periogard might help,but don't use it all the time.MAy be alternate nights only and a good anti-bacterial one like Colgate Total all the other nights and every mornings should be a good combination.
Do let us know what happens to your front teeth.But you should see your orthodontist asap!
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