Practice Scale and Organizational Affiliation in U.S. Dentistry: A Cross-Sectional Analysis of the 2024 American Dental Association Health Policy Institute Practice Modality Data
Background. Consolidation of dental practice into multi-site groups and dental support organizations (DSOs) is widely described as the dominant structural trend in U.S. dentistry, yet the most recent primary data release characterizing practice scale — the American Dental Association Health Policy Institute (ADA HPI) 2024 practice modality dataset — was published as tabular data without an accompanying analytic report. This paper provides a formal statistical characterization of that release. Data and Methods. The dataset covers 198,117 of 212,459 practicing U.S. dentists (93.2%), classified into six practice-size categories and, separately, by DSO affiliation, with cross-tabulations by career stage, sex, specialty, and jurisdiction (50 states and the District of Columbia). We compute descriptive distributions; Pearson and Spearman correlations between jurisdiction-level single-location prevalence and DSO affiliation; ordinary least squares gradients; and within-jurisdiction paired comparisons across career stages. All analyses are conducted at the level of published aggregates; microdata were not available. Results. In 2024, 72.7% of U.S. dentists practiced in single-location settings (33.6% in one-location, one-dentist practices; 39.1% in one-location, multi-dentist practices), while 16.1% were DSO-affiliated. Career-stage gradients are large and directionally uniform: single-location prevalence rises from 59.4% among dentists up to 10 years from dental school to 83.3% among those more than 25 years out, and the late-career share exceeds the early-career share in all 51 jurisdictions (mean paired difference 18.0 percentage points; t(50) = 23.54; p < .001). Across jurisdictions, single-location prevalence and DSO affiliation are strongly inversely associated (Pearson r = -0.86; Spearman rho = -0.83; p < .001), an association that is partly definitional given the classification rules and is treated here primarily as a construct-validity check. Jurisdiction-level single-location prevalence ranges from 63.9% (Arizona) to 87.0% (Alaska). Conclusions. Single-location practice remains the modal organizational form in U.S. dentistry by a wide margin. Consolidation, while real and growing, is concentrated among early-career dentists; cross-sectional data cannot distinguish cohort replacement from life-cycle transitions, and both mechanisms carry different long-run implications. The findings bear on workforce policy, antitrust analysis, and the design of technology and services markets that serve small dental practices.