The National Dental Practice-Based Research Network Adult Anterior Openbite Study: Treatment Success

Thesis (Master's)--University of Washington, 2019Introduction: Anterior openbite (AOB) continues to be a challenging malocclusion for orthodontists to treat and retain long-term. There are many orthodontic treatment modalities used to treat AOB in adult patients, but there is no consensus on which modalities are most successful. This study aims to identify the overall success rate of AOB orthodontic treatment in the adult population across the United States, as well as factors that influence treatment success. Methods: Practitioners and their adult AOB patients were recruited through the National Dental PBRN. Patient dentofacial and demographic characteristics, practitioner demographic and practice characteristics, and factors relating to orthodontic treatment were reported. Treatment success was determined from post-treatment lateral cephalometric films and intraoral frontal photos. Treatment was categorized into four main groups: aligners, fixed appliances, TADs and orthognathic surgery. Extractions were also evaluated. Univariate and multivariate models were used to evaluate how treatment success varies with treatment modality, pre-treatment dentofacial characteristics, and patient and practitioner demographic and practice characteristics. Results: End of active treatment data was collected from 84 practitioners and 254 patients. Eighty four percent of patients finished with positive vertical overlap of all incisors and 93% with positive overbite on the post-treatment lateral cephalogram. While there were no statistically significant differences in success rates between the treatment groups, patients treated with orthognathic surgery had an increased odds for success when compared to those treated with fixed appliances only. Treatment success was also associated with academic practice setting, pre-treatment IMPA 90°, no to mild pre-treatment crowding, and treatment duration < 30 months. Conclusion: The success of orthodontic treatment in adult AOB patients who participated in this study was very high. While there was a range of success for the major treatment modalities, orthognathic surgery was the only treatment modality that reached statistically significance. There were some pre-treatment dentofacial characteristics and treatment factors associated with successful closure of AOB