CASE STUDY CLASS II CORRECTION CASE Using Herbst & Twin Force Appliances By Khoi Nguyen, DDS Fig. 1: INI composite pictures. Fig. 2: Cephalometric radiograph. P arents will often ask for orthodontic treatment when their dentist informs them that their child has crowding. They can see that the crowding of teeth is affecting their child's smile. Sometimes, it is not so obvious if a child has a retruded chin. The dental profession classi-fies this as a Skeletal Class II and dental Class II Division II. Accom-panying the retruded chin is often a large overjet. Parents should be shown their child's profile at the current retruded position. Then with instructions, the dentist should guide the child to the more normal chin position. This normal position gives the child a more natural profile. Additionally, their lower face is fuller. After seeing the difference, parents will prefer this new jaw position. Children with a retruded chin can have the appearance of a child who suffers from allergies; their posture can be poor and their mouths are often found to be slightly opened. The following case study involves a 9-year-old boy in late mixed dentition. The mother's chief complaint was the flared upper incisors. The patient also presented with a retruded chin and large over-jet. The combination of retruded chin and flared upper incisors resulted in a very large overjet. This case is interesting because it involved being treated with non-extraction mechanics using a Herbst appliance. Then, late in treatment, a Twin Force appliance was placed as elastic wear did not produce the desired overjet correction. Treat-ment was divided into Phase I with the goal of correcting the jaw rela-tionship and correcting the flared incisors. Optional Phase II treat-ment was also presented. Treatment began at age 9.4 years and ended at age 12 years, 2 months. The Herbst appliance is one of the appliances taught in the Academy of GP Orthodontic's Early Treatment course. The Twin Force appliance is one of the appliances taught in the AGpO's Twelve-Session Hands-on Course. By 32 Winter 2020 JAOS
Journal of the American Orthodontic Society Winter 2020: Page 32
