>Over a century of orthodontic research: A bibliometric and scientometric analysis of growth, citation impact, and structural evolution

INTRODUCTION: Orthodontic research has grown for more than a century, but its evidence base has not been examined across its full history. We evaluated its evolution in publication growth, citation impact, journal distribution, geographic contribution, and international collaboration. METHODS: We froze an OpenAlex topic-indexed corpus ("Orthodontics and Dentofacial Orthopedics") on December 31, 2025, and, after removing pre-1900 metadata artefacts, analysed 46,265 records from 1900 to 2025; in a two-rater manual check of a random sample, 92.4% of records were genuinely orthodontic (precision; recall not assessed). We assessed growth, structural transitions, citation inequality, field-weighted citation impact (FWCI), publishing concentration, country-level output, language, and collaboration. RESULTS: Output accelerated after a structural changepoint in 1996: the absolute slope of annual output (records added per year) increased more than 25-fold while the proportional growth rate remained broadly stable; 86.5% of the corpus dates from 1996 onward. Citation impact was skewed (median 2 citations, 35.7% uncited, Gini coefficient 0.794). Annual mean FWCI exceeded 1.0 from 2022 onward, although over short citation windows. Among venue-resolved records, the annual Herfindahl-Hirschman Index fell from 920 in 1990 to 97 in 2024, and 95% of the 2024 output was spread across 460 venues (1455 across all years). Among the 62.5% of records with resolved affiliations, the United States led cumulative output under whole counting (5265 papers), followed by Brazil (3360) and India (2757); India led annual output in 2021-2024. Internationally co-authored papers were associated with higher citation impact than single-country papers in every period (median FWCI 0.90 versus 0.47). CONCLUSION: Orthodontic research is now predominantly post-1990s, globally redistributed, dispersed across a large journal ecosystem, and highly asymmetric in citation impact. These results provide a quantitative baseline; they are consistent with, but do not by themselves establish, implications for literature retrieval, journal selection, and collaborative research strategy.