Clinical Practice Pearls of the Pacific A Simple Way to Increase the Activation Range of the Bionator for Class II Correction Dr. James Chen San Francisco, CA PCSO Bulletin Contributor 32 Early interceptive orthodontic treatment is usually targeted and focused at addressing major occlusal discrepancies. One of the most common malocclusions seen and treated in the mixed dentition is the Class II malocclusion. Treatment of this malocclusion ranges from classical approaches such as headgear to more recent techniques such as the Carriere Motion Appliance. We use a functional appliance, the Bi-o-na-tor, for Class II malocclusions in both maxillary protrusion and mandibular retrognathic cases in my private practice as well as in the community clinic where I serve (Figure 1). We use this appliance because of its ease of wear and effectiveness at correcting the malocclusion. eruption in open bite cases. The traditional Bi-o- na-tor is often made with just a labial bow for the upper anterior teeth and a transpalatal loop for stability. The changes we have implemented into our Bi-o-na-tor are Adams clasps for stability and sagittal expansion screws to increase the amount of correction one Bi-o-na-tor can provide. In this pearl, I want to highlight some small additions we have learned to implement in our Bi-o-na- tor that have improved some of its effects as well as reduced the need to remake new ones once the Bi-o-na-tor is no longer active during treatment. The standard Bi-o-na-tor can be made to either facilitate posterior eruption for deep bite cases or limit We place Adams clasps on the upper first molars (Figure 1) to improve the retention of the Bi-on - a- tor. While the retention arises mostly from the patient biting into the Bi-o-na-tor, the additional Adams clasps help to hold the Bi-on - a-tor steady during insertion. The second addition we have is the sagittal expansion screws (Figures 1 and 2). The Bi-o-na-tor is made by posturing the patient forward into an edge-to-edge incisal relation. More posturing is sometimes needed during the course of treatment. In these situations, instead of making a new Bi-o-na-tor, moving the anterior portion of the Bi-o-na-tor (incisal caps) with sagittal expansion screws gives the extra movement some patients need at the end. Figure 1. Modified Bionator buccal view Figure 2. Modified Bionator occlusal view PCSO Bulletin    Spring 2021