Different ligature configurations. Please help!

[Slader01]

Why is it that some people have 1 elastic ligature (o-ring) per bracket, while some people have two per bracket, and others have them in a figure 8 style. I'm curious, because I've always had a single tie until my last adjustment. They gave me all double ties on my bottom teeth, except one of my canines has a figure 8 on it (this tooth is slightly rotated). I'm wondering what the double ties do? Do they hold the wire in tighter or looser?? Beats me. I'd appreciate it if you guys could help. Thanks

[littlething]

I believe it is so that the tooth is better engaged to the wire. They switched out the o-rings on my rotated teeth to figure 8s, and now they have wire ligatures on them as of yesterday. They told me it was so that those teeth are engaged to the wire to help them move faster.

[jfriend33]

I have no idea but all I have read is that figure 8 is definitely more friction and less movement against the archwire! My ortho does not agree with me but que sera sera.

My personal preference is power chain. and do a regular ligature on a few of the teeth in case it breaks.