Brett McParland · Zenodo (CERN European Organization for Nuclear Research) 2026 · cross-sectional analysis of aggregate administrative data · n=198,117

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

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Level 4 - case-series / case-control

Level 4 by design analogy: cross-sectional observational analysis of aggregate registry data.

OpenAlex W7170946501 · doi:10.5281/zenodo.21536509 · record verified 2026-08-26

What was done

Cross-sectional statistical analysis of the 2024 American Dental Association Health Policy Institute (ADA HPI) practice modality dataset, covering 198,117 of 212,459 practicing U.S. dentists (93.2%) across 50 states and the District of Columbia. The authors evaluated published aggregate tables categorizing dentists into six practice-size tiers and dental support organization (DSO) affiliation, cross-tabulated by career stage, sex, specialty, and jurisdiction. Analyses included descriptive distributions, Pearson and Spearman correlation coefficients, ordinary least squares gradients, and paired t-tests comparing career stages across jurisdictions.

What was found

In 2024, 72.7% of practicing U.S. dentists worked in single-location practices (33.6% solo, 39.1% multi-dentist), while 16.1% were affiliated with a DSO. Single-location practice increased monotonically across career stages, from 59.4% among dentists 10 or fewer years from dental school to 83.3% among those more than 25 years out. The late-career single-location share exceeded 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 were inversely correlated (Pearson r = -0.86; Spearman rho = -0.83; p < .001), with single-location rates ranging from 63.9% in Arizona to 87.0% in Alaska.

Why it matters

This study provides empirical baseline metrics demonstrating that single-location practice remains the dominant organizational form in U.S. dentistry, while identifying that corporate consolidation is disproportionately concentrated among recent dental graduates.

Limits

The study is restricted to published aggregate cross-tabulations because underlying microdata were unavailable. Due to its cross-sectional design, the data cannot distinguish whether higher DSO affiliation among early-career dentists represents a permanent cohort replacement or a transient life-cycle phase prior to independent practice ownership. Additionally, 6.8% of practicing U.S. dentists were missing from the modality dataset.

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