Failure of maxillary canine retainers for fixed prostheses

A statistical survey of fixed prostheses with failed retainers, combined with information on the arch distribution of abutment teeth, supports the clinical impression that retainers on maxillary canines have a disproportionately high failure rate. The probable contributing factors are the form of the canine clinical crown, the distribution of occlusal force, and the paths of abutment tooth displacement. These factors are discussed and clinical techniques for countering their adverse effects are described.