Comparison of the Quality of Orthodontic Treatments Evaluated in Cast and Digital Models According to the ABO-OGS

Sep 30, 2026

The Objective Grading System (ABO-OGS) provides an objective method for evaluating orthodontic treatment outcomes and has been adopted by institutions to judge results. This study compared physical and digital models using ABO-OGS parameters in finished treatments and determined the proportion of cases meeting ABO case-category specifications in a graduate Orthodontics program (Universidad Cooperativa de Colombia, Bogotá campus) from 2017 to 2021. Retrospective analysis of 32 patients assessed standardized plaster casts, digitized casts, and panoramic radiographs. Manual and digital scoring showed almost perfect agreement with an ICC(A,1)=0.999, while 69% passed the threshold (≤30).

LanguageEnglish

CategoryHealthcare

FormatPDF

Pages12

Reading Time30 min

AccessFree to download

Introduction

Quality assessment and indices

Methods

Retrospective descriptive study and model evaluation

Results

Agreement between manual and digital ABO-OGS scoring

Passing threshold and differences by parameter

Conclusions

Clinical interchangeability and validity of digital models

Article Comparison of the Quality of Orthodontic Treatments Evaluated in Cast and Digital Models According to the ABO-OGS Linda Delgado-Perdomo 1, Christian Ñustes-Peña 1, Yegny-Katherine Trillos-Mora 1, Stephanie Patiño-Méndez 1 and Alejandro Pelaez-Vargas 2, * Academic Editor: Juan Martin Palomo Received: 22 July 2025 Revised: 17 October 2025 Accepted: 12 November 2025 Published: 22 December 2025 Copyright: © 2025 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license. 1 Faculty of Dentistry, Universidad Cooperativa de Colombia, Bogotá 111311, Colombia; [linda.delgado@ucc.edu.co](linda.delgado@ucc.edu.co) (L.D.-P.); [cristhian.nustes@campusucc.edu.co](cristhian.nustes@campusucc.edu.co) (C.Ñ.-P.); [yegny.trillosm@campusucc.edu.co](yegny.trillosm@campusucc.edu.co) (Y.-K.T.-M.); [stephanie.patinom@campusucc.edu.co](stephanie.patinom@campusucc.edu.co) (S.P.-M.) 2 Faculty of Dentistry, Universidad Cooperativa de Colombia, Medellín 055422, Colombia * Correspondence: [alejandro.pelaezv@campusucc.edu.co](alejandro.pelaezv@campusucc.edu.co) Abstract The Objective Grading System (OGS) developed by the American Board of Orthodontics (ABO-OGS) provides an objective method to evaluate the quality of orthodontic treatment outcomes. Initially designed to assess individual orthodontists, it is now widely adopted by institutions to evaluate treatment results. However, access to digital cast analysis remains limited in developing countries due to the high cost of specialized software. Objectives: This study aimed to compare physical and digital models based on ABO-OGS parameters in finished treatments and to determine the percentage of cases that met the ABO case category specifications in the graduate Orthodontics program at Universidad Cooperativa de Colombia (Bogotá campus) between 2017 and 2021 . Methods: A retrospective descriptive study analyzed clinical records from 32 patients who completed orthodontic treatment between 2017 and 2021 . Standardized plaster casts, digitized casts, and panoramic radiographs were evaluated. Manual assessment was performed using the ABO-OGS gauge on physical casts, while digital assessment was conducted using software on scanned models. Eight ABO-OGS parameters were scored following established guidelines. Results: Manual and digital ABO-OGS assessment demonstrated almost perfect agreement. The intraclass correlation coefficient was ICC (A,1) = 0.999 (p < 0.0001), and Bland–Altman analysis revealed a negligible mean bias of 0.34 points with narrow 95% limits of agreement (–0.60 to 1.29) . Although the Wilcoxon signed-rank test detected a statistically significant difference (p = 0.001), the median scores were clinically equivalent (23.0 vs. 23.5) . Overall, 69% of cases met the ABO-OGS passing threshold (≤30), while 31% did not (>30) . The greatest differences between manual and digital methods were observed in occlusal contacts, marginal ridges, and buccolingual inclination. Occlusal relationships, overjet, and alignment contributed the most to the total ABO-OGS scores. Both linear (Least Absolute Shrinkage and Selection Operator regression—Lasso) and non-linear (Random Forest) models consistently identified the same core predictors, confirming the robustness of digital and manual workflows in capturing key determinants of treatment outcomes. Conclusions: Manual and digital methods of ABO-OGS assessment are clinically interchangeable. Despite small statistical differences, digital models provided reproducible results, with 69% of cases meeting ABO-OGS passing criteria. These findings support the validity of digital models as a reliable alternative for orthodontic outcome evaluation. Keywords: ABO-OGS; digital model; analogic model; treatment; orthodontic 1. Introduction The orthodontic treatment is focused on improving craniofacial esthetics and

FAQs

What is the ABO-OGS used for in orthodontics?

ABO-OGS is an objective grading system for evaluating the quality of orthodontic treatment outcomes, originally for assessing orthodontists and now widely used by institutions to evaluate treatment results.

How did the study compare physical and digital orthodontic models?

The retrospective study analyzed clinical records using standardized plaster casts and digitized casts. Manual assessment on physical casts used the ABO-OGS gauge, while digital assessment used software on scanned models, scoring eight ABO-OGS parameters.

What did the study find about the agreement between manual and digital ABO-OGS assessments?

Manual and digital assessments showed almost perfect agreement, with ICC(A,1)=0.999 and a negligible mean bias in Bland–Altman analysis. Although a statistical difference was detected, median scores were clinically equivalent.

Sep 30, 2026

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