This tag implies that the bands and artists are Serbian or originated in Serbia. Music represented by this tag is often highly commercial. Other, possibly better, Serbian tags are, for example Novi Val or nova srpska scena.
Relapse means that the teeth can take up to one year or more to stabilize after treatment. If you had gaps between your teeth before treatment, the retention period will be longer. Usually, retainers are worn for as long a time as you have had your braces.
The average treatment time for invisalign is 12 months. The aligners provide .25mm of movement to the teeth per aligner. The more crowded your teeth are the more time it will take. The best way to insure that you are going to minimize your time in aligners is to wear them for 22+ hours a day and change into your next aligner every two weeks.