Superimposition and structural analysis.
Superimposition on the lower border of the mandible has been severely criticized. It has allegedly been responsible for causing chaos and confusion in the literature. This report indicates that this is not true and that superimposition on the lower border of the mandible is valid. We have shown that changes resulting from superimposing on implants are a part of the sella-nasion superimposition. The implant changes are contained within the sella-nasion superimposition and are a part of it. The gonion angle grows approximately parallel to the mandibular plane. The lower border of the mandible is a part of the big picture all through the growing period, always containing the implant changes. The mandibular plane changes its inclination as the relation of vertical to horizontal growth changes. Examples are shown to illustrate the "give and take" between vertical and horizontal growth, and its effect on the facial complex. Objective evidence is shown that seems to indicate that the implant changes may have been counted and then counted again. This new analysis places a different interpretation on the implant studies.