Recently, self ligating orthodontic brackets have become more popular. They have been around in one form or another for a while, but companies like GAC and 3-M have come out with more refined versions that have some sort of latch to hold the wire in place. The GAC shown here on the left has a clasp (shown in yellow) that moves up to hold the wire in place. We are begining to incorporate some of these into our orthodontic practice. One concern with traditional alastic ligatures or even wire ligatures is the difficulty of proper oral hygiene around the bracket area. The self ligating bracket provides some advantage in this area. The main advantage is that it will take less time to change wires. That means shorter orthodontic appointments for the patient and more efficiency for the doctor and staff. The only problem is that you can't get the cool colors available with alastics.
This one from 3-M has little C clasps on each side.