© 2018 by The EH Angle Education and Research Foundation, Inc. Objectives: To describe the demographic and practice characteristics of the clinicians enrolled in a large, prospective cohort study examining recommendations and treatment for adult anterior open bite (AOB) and the relationship between these characteristics and practitioners' self-reported treatment preferences. The characteristics of the AOB patients recruited were also described. Materials and Methods: Practitioners were recruited from the National Dental Practice-Based Research Network. Participants in the study consisted of practitioners and their adult AOB patients in active treatment. Upon enrollment, practitioners completed questionnaires enquiring about demographics, treatment preferences for adult AOB patients, and treatment recommendations for each patient. Patients completed questionnaires on demographics and factors related to treatment. Results: Ninety-one practitioners and 347 patients were recruited. Demographic characteristics of recruited orthodontists were similar to those of American Association of Orthodontists members. The great majority of practitioners reported using fixed appliances and elastics frequently for adult AOB patients. Only a third of practitioners reported using aligners frequently for adult AOB patients, and 10% to 13% frequently recommended temporary anchorage devices (TADs) or orthognathic surgery. Seventy-four percent of the patients were female, and the mean age was 31.4 years. The mean pretreatment overbite was 2.4 mm, and the mean mandibular plane angle was 38.88. Almost 40% of patients had undergone orthodontic treatment previously. Conclusions: This article presents the demographic data for 91 doctors and 347 adult AOB patients, as well as the practitioners' self-reported treatment preferences.