A number of studies examined the forces and moments developed during wire ligation with conventional and self-ligating brackets and force relaxation of polymeric elastics, employing custom-made configurations.

These papers revealed that the direction of movement and number of teeth engaged in the arch, significantly affect the force applied to teeth with various wire-bracket combinations.

 

Pubmed link

Retainers
Forces
Biomechanics
Self-ligation
Mechanical Properties