Three-dimensional printed model of impacted third molar for surgical extraction training

Objectives Extraction of impacted mandibular third molars is one of the most common surgical procedures performed at dental clinics; however effective training models for teaching oral surgery to dental students are limited. This study aimed to use three-dimension (3D) printing technology to develop an effective training model for impacted third molar extraction. Methods The data for the 3D model were digitally processed using high-resolution computed tomography, and two common, but different patterns of impacted third molars were simulated using computer-aided design. Thereafter, the model was printed using the 3D-printing technology, and the efficiency of the 3D-printed model and an animal model (pig mandible) were compared using a five-point Likert scale by 35 oral surgeons in the oral surgery department and 208 students of stomatology in the internship stage. Results The 3D-printed model consisted of three parts: a non-replaceable part (i.e., the body of the mandible and the teeth from the left first molar to the right first molar) and two replaceable parts (i.e., the part of the ascending ramus of the mandible, as well as the second and third molars). It was covered with a layer of rubber-like material to simulate the gingiva. For the comparison between the 3D-printed and animal models, a total of 205 questionnaires were collected. Both oral surgeons and students agreed that the 3D-printed model was better than the animal model in terms of total value and the anatomy of the bone and teeth, simulating the surgical procedure (p < 0.05), while the two models achieved similar results for haptic feedback of the soft tissue (p > 0.05). Conclusions The 3D-printed model is realistic and effective for learning impacted third molar extraction and received positive feedback from students and oral surgeons. This model can significantly improve the pre-clinical skill training of dental students.