Tandem concept in the nonextraction treatment of class II malocclusion

1. A systematic controlled nonextraction approach in the treatment of certain Class II malocclusions exhibiting arch-length deficiencies has been presented. 2. Clinical cases, diagnostic criteria for case selection, the biomechanics of this tandem force system, time sequence in tooth movement, and ways to avoid untoward sequelae have also been offered. 3. The major advantages in utilizing the basic extraoral appliance and auxiliary mechanisms are as follows: A. various groups of tooth movements are initiated in one or more areas of both dental arches simultaneously. B. Orthodontic pressures are within physiologic limits. C. A minimum number of bands is required. D. Positive control of anchorage is ensured. E. Class II mechanics is not necessary. 4. In each of the four cases presented, the anteroposterior and mediolateral changes that occurred resulted in an increase in the linear length and width of the maxillary and mandibular dental arches. A sufficient increase in the maxillary apical base was also noted and may prove to be a significant yardstick in measuring the stability index of each case. 5. Photographic and cephalometric evaluation revealed that the facial contour and the relative position of the mandibular incisors were not adversely affected.