Orthodontic extraction decision-making under standardized clinical conditions: a case-based study

Determining whether to extract teeth remains one of the most challenging aspects of orthodontic treatment planning as it requires consideration of multiple dental, skeletal, and soft-tissue factors. Although established diagnostic criteria and predictive models are available, considerable variation in extraction decisions persists, particularly in borderline cases. To examine how orthodontists make extraction decisions when assessing the same standardized clinical cases, focusing on variation in their recommendations and the clinical factors associated with these decisions. Orthodontic specialists and postgraduate trainees completed an electronic cross-sectional survey. They assessed 20 standardized cases with complete diagnostic records and selected either extraction or non-extraction treatment while identifying the factors that influenced each decision. Data were analyzed using descriptive statistics, Cochran’s Q test, Fleiss’ kappa, and cross-classified mixed-effects logistic regression with random intercepts for orthodontist and case. A total of 104 orthodontists completed the survey, providing 2,080 clinician–case decisions across 20 standardized cases. Profile concerns, crowding severity, and incisor inclination were the most frequently reported factors influencing extraction decisions. Inter-rater agreement was fair (Fleiss’ κ = 0.303). In the cross-classified mixed-effects model, none of the six case-level cephalometric measurements showed a statistically significant association with extraction recommendations (all p > 0.05). The estimated random-intercept standard deviations were 0.451 for orthodontist and 1.262 for case. Extraction recommendations varied considerably among orthodontists, particularly for borderline cases, despite assessment of the same standardized clinical information. Within this sample, no statistically significant adjusted associations were detected between the six cephalometric measurements examined and extraction recommendations after accounting for differences between orthodontists and cases. However, the limited number of unique cases and uncertainty in the estimates warrant cautious interpretation and limit generalizability.