Abstract: Objective: To quantify the intercrestal line angle (ICLA) in edentulous patients using digital technology and to translate the ICLA parameter into clinical practice for improving the stability of complete dentures. Methods: Sixteen edentulous patients who received complete denture treatment at the Department of Prosthodontics, Guangzhou Medical University, from December 2022 to June 2024 were included. All participants were taken functional closed-mouth impression and recorded jaw relation according to standard protocols. Digital casts were obtained by scanning the definitive impressions. In the control group, automatic tooth arrangement was performed using the 3Shape Dental System software, the technician makes adjustments based on experience. In the experimental group, the ICLA was measured bilaterally at the first molar regions within the same software, and tooth arrangement was then adjusted accordingly to achieve individualized alignment. Diagnostic dentures were designed and 3D printed for both groups. During clinical try-in, denture stability was compared, occlusal force distribution was evaluated using the T-Scan system, and patient satisfaction was assessed through questionnaires. Results: A total of 16 edentulous patients were enrolled in this study. During the diagnostic denture trial wear phase, the experimental group exhibited superior stability in maxillary/mandibular stability examination and occlusal examination compared with the control group, characterized by a significant reduction in denture tilting and displacement. T-Scan occlusal analysis results showed that the experimental group had more symmetrical left-right occlusal force distribution, with significantly better occlusal balance indicators than the control group. Satisfaction questionnaire results indicated that patients scored high in dimensions such as "masticatory ability", "comfort", and "stability". Conclusion: Personalized tooth arrangement based on digitally measured ICLA can improve denture stability, occlusal force distribution, and patients' subjective post-insertion experience during the short-term trial wear phase.

Key words: intercrestal line angle, tooth arrangement, denture stability, digital technology