Is dynamic occlusal design necessary for anterior guidance recovery in the computer-aided design process? An in vitro study

This study aimed to assess the effectiveness of patient-specific motion in restoring anterior guidance and to investigate the influence of occlusal plane position within a virtual articulator on the design of the anterior guide slope for incisors. Twenty participants' intraoral scan, occlusal plane position, and jaw motion data were recorded. The maxillary anterior teeth were virtually prepared, and the crowns were designed based on average virtual articulator (AVR), personalized virtual articulator (ART), and patient-specific motion (PSM). The anterior guide slope of maxillary central incisors (S1, S2, Sc, Sp) and the mesio-distal angle (MDA) of the canine of prostheses were compared to that of natural teeth (NAT). One-Way ANOVA was utilized to evaluate the effectiveness of the three methods in restoring the anterior guidance of maxillary anterior teeth. The comparison of Sp and MDA showed no significant difference between the PSM and NAT groups (p > 0.05). However, Sp of the ART group was significantly smaller, while MDA was higher than that of the NAT group (p < 0.05). Sp did not differ significantly (p > 0.05) when the angle of the occlusal plane (AOP) was small. As the AOP increased, Sp of the ART and AVR groups were significantly smaller than that of the NAT group (p < 0.05). With a large AOP, Sp of the ART group was notably smaller than that of the NAT group (p < 0.05), while there was no significant difference between the AVR and NAT groups (p > 0.05). Occlusal design based on patient-specific motion proved more effective in restoring natural anterior guidance. The anterior guidance of prostheses designed using a virtual articulator was influenced by occlusal plane position. The utilization of a jaw motion tracer facilitated the transfer of personalized occlusal plane positions and recorded jaw motion, which can be integrated into the digital prosthetic workflow for virtual occlusion adjustment. Occlusal design based on patient-specific motion more effectively restored lingual guidance of maxillary anterior crowns.