Zygomatic fractures account for 10% to 15% of all facial fractures. The surgical management of isolated zygomatic arch fractures usually requires open reduction treatment without fixation through an intraoral access. Therefore, the main problem in the non-fixed treatment of zygomatic arch fractures is related to the difficulty in obtaining a stable reduction for a period long enough to guarantee the physiological bone healing process. We propose an innovative “in-house” rapid prototyping (RP) protocol for the 3D-zygoma mask manufacture of a patient-specific protective device to apply after zygomatic arch fracture reduction. Our study includes 16 consecutive patients who underwent surgical open reduction for an isolated zygoma fracture without fixation between January 2017 and February 2018. The patients received regular postoperative checks at weeks 1 and 2. Before the device was removed, a multiple choice questionnaire was administered to measure the degree of wearability of the mask. The estimated cost of the production is around €5 per case and the construction time is around 90 minutes. Based on the encouraging results, obtained in our experience, we hope that other studies can be conducted to confirm our procedure and improve its functionality in the field of facial trauma.