Do 3D-printed craniofacial fracture models improve learning outcomes in maxillofacial trauma? A multicenter cluster-randomized trial

Teaching maxillofacial traumatology is challenging, as it requires not only theoretical knowledge but also advanced visuospatial skills. Conventional educational resources such as CT scans and diagrams offer limited support for understanding complex three-dimensional fracture patterns. Three-dimensional (3D) printing has emerged as a promising educational tool, yet its pedagogical impact in maxillofacial surgery remains insufficiently investigated. This prospective, multicenter, cluster-randomized controlled trial was conducted at three French medical faculties (Nice, Tours, and Grenoble). Medical students were randomized to receive either a standard lecture alone (control group) or the same lecture supplemented with full-scale 3D-printed skull models representing 18 isolated craniofacial fractures derived from real patient CT scans (intervention group). Knowledge acquisition was assessed using identical pre- and post-tests consisting of a 25-item multiple-choice questionnaire. Additional variables included demographic data, prior exposure to 3D-printed models, video-game practice, and visuospatial ability assessed by a mental rotation test. The primary outcome was learning gain, defined as the difference between post- and pre-test scores. Student satisfaction was evaluated in the intervention group. A total of 112 students were included (73 intervention, 39 control). Baseline characteristics and pre-test scores were comparable between groups. The mean learning gain was significantly higher in the intervention group than in the control group (+ 5.56 ± 4.68 vs. +3.62 ± 4.06, p = 0.024), corresponding to a moderate effect size (Cohen’s d ≈ 0.45). The adjusted analysis of post-test scores showed a favorable but nonsignificant trend toward higher performance in the intervention group ( p = 0.074). The item-level analysis revealed consistent improvement across all the questions in the intervention group, whereas gains were partial in the control group. Student satisfaction was high, with 91.8% of participants reporting that the 3D-printed models improved their understanding of maxillofacial trauma. The integration of 3D-printed craniofacial fracture models into trauma teaching significantly enhances student learning and is associated with strong learner acceptance, although the confounder-adjusted analysis of post-test scores showed only a favorable, statistically nonsignificant trend. Three-dimensional educational media effectively complements traditional lectures by facilitating spatial reasoning and reducing cognitive load. This multicenter cluster-randomized study provides encouraging, although preliminary, support for the broader incorporation of 3D printing into trauma education, with potential extension to other surgical disciplines and future integration with immersive technologies.