Questionnaires were sent to seventeen leading orthodontists of the nation. Thirteen replied. Seven of the thirteen answered the questions in detail. Six have also contributed viewpoints. Of the thirteen who replied, nine use the guide plane, three do not, and one seldom uses it. These questions were entirely mechanical in character. However, several could not discard the scientific viewpoint. Of the three who do not use the guide plane, two, Doctors Joseph E. Johnson and James D. McCoy, use attachments of their individual designs on anterior bands. We can recognize that these plans stabilize anchorage of individual jaws, and as the jaws are developed, improved function brings about normal or near-normal depth of the lower part of the face without the use of the guide plane. Dr. John V. Mershon, the third contributor who does not use the guide plane, does not describe his plan whereby the use of this appliance is not necessary. On the question of mechanical cause of open-bite during treatment the majority opinion is that improper manipulation rather than incorrect appliance is responsible. The mechanical cause brings about a tipping of the molars. This tipping can be avoided by the use of the labial appliances properly stabilized, either by bands carrying attachments or by ligating to the anterior teeth. From these opinions we would gather that properly stabilized labial appliances make the use of the guide plane unnecessary and prevent open-bite. However, the experiences of many of us have shown ready correction of posterior relation in both protrusion and retrusion without the use of the guide plane. We have also seen these conditions respond only after the guide plane was used. Then, in a few instances the use of the guide plane produced no result at all. There are differences of opinions on the subject of bone change. One claim is that the only change is in the alveolar process, while other opinions are that changes involve other areas. The terms “bite block,” “bite plane” and “guide plane” show a difference of opinion as to the correct name for the appliance while one contributor finds objection to the metal framework, but uses one of “vulcanite or similar material.” There was an appeal by one contributor for better nomenclature. While the scientific phase of orthodontics is most important, the mechanical side is not insignificant. Proper education in the basic principles in the dental curriculum, thus laying a better foundation for a better understanding of orthodontic problems by the orthodontists of the future, is essential. In conclusion I want to thank the contributors for their valuable comments. Without their cooperation this survey would not have been possible.