The Herbst appliance and its modifications - prevalence and individuality

OBJECTIVE: The aim of this study was to analyze the use of modified, cast splint Herbst appliances for the treatment of skeletal class II as an alternative to surgical bite correction over a period of five years. MATERIALS AND METHODS: The patient cases all originate from the patients of the Department of Orthodontics at the University Medical Center of the Johannes Gutenberg University Mainz, Germany and the orthodontic practice Dres. Zöller, Kaiserslautern, Germany. Inclusion criteria were orthodontic treatment with the Herbst appliance and its modifications. The type of modification, number and frequency of the different modifications were determined on the basis of patient files, X-ray documents, photos and models. RESULTS: Of a total of 2881 new admissions over a period of five years, 1751 patients came from the Department of Orthodontics at the University Medical Center of the Johannes Gutenberg University Mainz and 1130 from the orthodontic practice in Kaiserslautern. A total of 336 patients were treated with a Herbst appliance during the period mentioned. 14 (13%) of the cases from the Herbst patient collective of the University Medical Center and 45 (19%) of the cases from the orthodontic practice were classified as modifications. The following modifications could be determined in descending order: University Medical Center Mainz: Herbst for anchorage during space closure (65%) > distalization (14%) ≥ bar construction as a space maintainer (14%) > Herbst applicance for anchoring for the adjustment of impacted teeth (7%); orthodontic practice Kaiserslautern: Herbst appliance with quadhelix in the maxilla (42%) > distalization (27%) > space closure (15%) > bar construction as a space maintainer (9%) > adjustment of impacted teeth (7%), multiple modifications occurred at 11%. The combination of quadhelix and Herbst appliance as well as multiple modifications have not yet been used in the University Medical Center Mainz. As an alternative to dysgnathia surgery, 23 adult patients (> 18 years) from the University Medical Center and 22 from the orthodontic practice were treated with a Herbst appliance. CONCLUSION: Nearly 12% of Herbst appliances are used in everyday orthodontic practice and almost 18% of these are used with modification(s). The high anchoring quality and force-effect geometry of the Herbst appliance is suitable for combining and treating various other treatment tasks in addition to the classical treatment task of class II therapy.