Development of a 3D-Printed Guided Kit for Minimally Invasive Orthodontic Assessments: Design, Implementation, Evaluation

Thesis Abstract

The rapid advancement of digital fabrication and intraoral scanning has accelerated the adoption of minimally invasive orthodontic assessments, yet there remains a gap in tools that can reliably guide clinicians in performing accurate measurements while preserving patient comfort. This study addresses the problem by developing a 3D-printed guided kit designed to standardize minimally invasive orthodontic assessments, reduce measurement error, and streamline clinical workflow. The aim is to design, implement, and evaluate a reusable guided kit that integrates with existing digital workflows to enhance accuracy, efficiency, and patient acceptability in routine orthodontic assessments. Specific objectives include (1) defining functional and dimensional requirements based on clinician input and task analysis; (2) designing a modular, sterilizable, lightweight guided kit using CAD/CAM processes; (3) validating fit, accuracy, and usability through a phased testing protocol; (4) evaluating intra- and inter-operator reliability of measurements obtained with the kit; and (5) assessing patient-reported comfort and clinician-reported workflow impact. A mixed-methods approach underpins the methodology. The population comprises licensed orthodontists and postgraduate students (n=60) recruited from three university clinics. An initial quasi-experimental phase (n=30 patients) evaluates measurement accuracy against a gold-standard reference (CBCT-derived landmarks) and established intraoral measurements, using root-mean-square deviation (RMSD) and Bland-Altman limits of agreement. The remaining participants (n=30) participate in a longitudinal usability study over 12 weeks, employing think-aloud protocols and structured surveys. Data collection instruments include a validated usability questionnaire (System Usability Scale adapted for dental devices), a measurement accuracy checklist, and a patient comfort survey employing a 5-point Likert scale. Instrument validity is established through expert content validation (n=6 orthodontic faculty) and pilot testing (n=10 patients). Reliability is assessed via Cronbach’s alpha for internal consistency (target ? ? 0.80) and test-retest reliability for repeated measurements (intraclass correlation coefficient, ICC ? 0.75). Quantitative data will be analyzed using descriptive statistics, paired and independent t-tests, and ANOVA to compare measurement accuracy across operators and time points, with regression analysis to examine predictors of accuracy and efficiency. The agreement between the kit-based measurements and reference standards will be assessed via Bland-Altman plots and concordance correlation coefficients. Qualitative data from think-aloud sessions and open-ended survey responses will undergo thematic analysis, converging with quantitative findings to yield a comprehensive evaluation of usability and practical impact. The study will be framed by the Theory of Planned Behavior to interpret clinician adoption intentions and the Technology Acceptance Model to elucidate perceived usefulness and ease of use. Expected findings include improved measurement precision, evidenced by RMSD reductions of at least 0.3 mm compared with conventional methods, and higher inter-operator reliability (ICC ? 0.85) when using the kit. It is anticipated that the kit will reduce assessment time by approximately 15–20% without compromising diagnostic accuracy. Usability scores are expected to reflect high acceptability (SUS ? 78), with positive feedback on ergonomics, sterilizability, and integration with digital workflows. The study also anticipates that the kit will enhance patient comfort by limiting invasive access and reducing chair time, thereby improving patient satisfaction scores. The contribution to knowledge includes (1) a validated 3D-printed guided kit specifically tailored for minimally invasive orthodontic assessments, (2) a rigorous evaluation framework combining quantitative accuracy metrics with qualitative usability insights, and (3) empirical evidence on the impact of digital-guided tools on clinical workflow and patient experience. The main conclusion is that the 3D-printed guided kit can standardize minimally invasive orthodontic assessments, improve measurement reliability, and positively influence clinician acceptance and patient comfort when integrated with existing digital workflows. Recommendations include scaling production with standardized sterilization protocols, conducting multi-center trials to confirm generalizability, and developing training modules to maximize adoption among clinicians.