This document summarizes the history and components of removable orthodontic appliances. It discusses how George Crozat developed one of the first removable appliances in the early 1900s using precious metals. It then outlines the development of various removable appliances throughout the 20th century in Europe and the United States. The document describes the common components of removable appliances including springs, screws, elastics, bite plates and retentive components like Adams clasps. It discusses the advantages, disadvantages and appropriate uses of removable appliances and how to properly fit, monitor and manage their use.