The treatment of Class-II malocclusions is probably the most widely published subject of our clinical activity. For over a century, clinicians have been opposed to whether it is possible to treat mandibular retrognathism, by increasing the mandibular size in the long term. The list of therapeutic proposals, which is already substantial, continues to grow with technical advances, the results of scientific publications, the emergence of new treatment philosophies, the opinions of eminent personalities, or the initiative of suppliers. In 1975, among the indications for the use of removable devices for the treatment of Class-II malocclusions, M. Château and Y. Le Gall 16 , wrote that the indisputable first choice according to them when their article