The quadrilateral analysis: an individualized skeletal assessment.

There must be a change in our approach to orthodontic diagnosis, especially in those cases involving skeletal dysplasias. The orthodontic practice of today requires a more in-depth diagnostic approach before a realistic treatment plan can be developed. An understanding of the problem that exists is emerging as the essential ingredient before appliance therapy can begin. Diagnosis should dictate the direction of treatment for both the orthodontist and the surgeon. A cephalometric analysis should be able not only to detect but to locate the area of the skeletal dysplasia. Surgery, if at all possible, should be performed where the problem exists. In many cases, it becomes rather confusing to determine whether or not surgical orthodontic treatment is indicated, because most of the cephalometric measurements that are used do not reveal whether a skeletal problem exists, its location, or its magnitude. We believe that current cephalometric analyses do not completely recognize the extent of the dysplasia or where it is located within the jaws. Because of this, surgery is performed by repositioning bones to mask the defect rather than to restore a normal balance between the bones of the face. The only recourse the surgeon has is to achieve an acceptable facial profile by relying on cephalometric norms or to make the necessary correction on what appears visually to be an acceptable profile. The quadrilateral analysis offers an individualized cephalometric diagnosis on patients with or without skeletal dysplasias. We believe that it is a reliable and accurate method of assessing whether orthodontic treatment, surgical treatment, or a combination of both is required to achieve a satisfactory result.