What are the advantages of spherical self-locking brackets compared with traditional metal self-locking brackets?

Spherical self-ligating bracket is a kind of spherical self-ligating bracket. Unlike the square brackets of traditional metal self-locking brackets, they have many edges and corners, which are easy to grind and cause oral ulcers. However, the spherical self-ligating bracket has a round and closed surface and few contours, which brings more comfort to the wearer, makes it easier to clean the teeth and makes the periodontal tissue healthier. The stress surface of traditional metal self-locking bracket is in multiple plane directions, which is easy to cause bracket to fall off because of the large stress on the bracket. However, the stress surface of spherical self-locking bracket is spherical, and the forces in different directions can be eliminated by "smooth curved surface", thus reducing the probability of bracket falling off and shortening the treatment course.