Background: Among the various types of malocclusion found in human population, class II division 1 is one of the most common. According to Dr. James McNamara, mandibular retrusion is the most common feature of class II division 1 malocclusion in growing children. It can be due to protrusive maxilla, retrusive mandible, or a combination of both. In patients who are at the end of prepubertal growth spurt or who are uncooperative, fixed functional appliances like Herbst, Forsus-FRD or Jasper Jumper can be used. Among all functional appliances for Class II malocclusion, the Herbst appliance is one of the most commonly used one. Aim of the study: To study dental and skeletal changes in patients with mandibular retrognathism following treatment with Herbst appliance using lat cephalogram. Materials and methods: The study was conducted in the Department of Orthodontics and Dentofacial Orthopedics of the Dental institution. For the study we selected 40 patients in the growing age from 8-14 years and bone age corresponding to the growth spurt, as revealed by a hand-wrist radiograph. Cephalometric radiographs of the patients were obtained at the beginning of the study (T1) and after 12 months of observation (T2). The change in the dento-skeletal parameters were studied by comparing T1 cephalogram and T2 cephalogram. Results: A total of 40 patients were selected in the study. The age of the patients ranged from 8-14 years. In case of skeletal changes, we observed significant increase in the spatial position of the mandible related to the anterior cranial base (SND) and significant reduction in the measurements related to maxillomandibular sagittal position (ANB, AO-BO). In case of dental parameters, we observed statistical changes on upper incisors position (1/NA degree) and on lower incisors tipping (1/NB degree), which resulted in significant reduction of interincisal angle. Conclusion: Within the limitations of the present study, it can be concluded that Herbst appliance used in class II malocclusion patients in growing age has significant improvement in the total mandibular length and anteroposterior relationship.
Keywords: Herbst appliance, functional appliances, malocclusion.