Aligners (removable mouthguards) - there is such an alternative. But they are still visible when communicating. They must be worn at least 22 hours a day and removed only at the time of meals. Treatment is an order of magnitude more expensive than braces and one more moment - treatment Aligners take more time. Plus a year or two.
There are also invisible Invisalign systems. The so-called lingual braces, which are attached to the inner surface of the teeth. But they are not suitable in all cases and have a strong effect on diction.
There are no "new ways". But there are new techniques and technologies. For example, orthodontic aligners (aligners). The aligners are individually modeled and changed from stage to stage of orthodontic treatment.
Mouth guards are much more convenient to use - they are unobtrusive and removable, that is, you can eat and brush your teeth as usual.
On account of the effectiveness of treatment with mouth guards, the opinions of dentists differ, but the main statement is that, all other things being equal, treatment with braces gives a more guaranteed result.
Still, treatment with mouth guards can definitely be called an alternative to treatment with braces.