Development and application of a multidimensional instrument to evaluate competency discrepancies in orthodontic practice

Abstract Background Contemporary orthodontic practice faces challenges related to treatment complications, often linked to deficiencies in multidisciplinary clinical competency. A clear understanding of the coordination across the stomatognathic system is essential, yet no standardized instrument exists to assess core skills. This study aimed to develop and validate a comprehensive assessment tool and evaluate current competency levels and associated factors among Chinese orthodontists across dental, periodontal, temporomandibular joint (TMJ), and myofunctional domains. Methods A cross-sectional survey was conducted across multiple regions of China from January to June 2025 among 434 practicing orthodontists. A three-component assessment instrument was developed through systematic expert review: Subjective Competency Scale (SCS), Clinical Practice Behavior Scale (CPBS), and Objective Knowledge Test for Orthodontists (OKTO). Psychometric properties were evaluated through exploratory factor analysis, reliability testing, and validity assessment. Competency variations across four domains were analyzed using Friedman tests, and demographic predictors were identified through stepwise multiple regression. Results The instrument demonstrated satisfactory reliability (SCS: Cronbach’s α = 0.897) and validity. Significant competency disparities existed across domains (all p < 0.001). Orthodontists showed highest competencies in dental areas (SCS: 4.45 ± 0.77; practice compliance: 78.00%) but substantial deficits in TMJ (SCS: 3.33 ± 1.17; practice compliance: 56.45%) and myofunctional domains. Objective knowledge patterns revealed adequate TMJ knowledge (82.58%) but poor myofunctional understanding (68.26%). Educational attainment emerged as the strongest predictor (β = 0.262, p < 0.001), followed by age (β = 0.201) and continuing education participation (β = 0.127). Conclusions This study represents an initial attempt to develop and validate a multidimensional competency assessment framework for orthodontists, with the aim of offering a structured approach to evaluating interdisciplinary clinical competencies. TMJ and myofunctional domain-specific deficiencies, which were found to be associated with educational attainment, may serve as potential risk factors affecting treatment stability and complication prevention within the Chinese clinical context. This instrument, with preliminary validation evidence based on a Chinese sample, offers a tentative framework for systematic competency evaluation that requires further validation across diverse contexts.