Background <p>Conservative treatment of condylar fractures requires the use of occlusal splints. However, limited mouth opening, pain, and tooth damage often prevent timely impression taking, which hinders the fabrication of the occlusal splints. Therefore, there is an urgent need for a convenient and new method. The objective of this study is to evaluate the clinical outcomes and feasibility of innovative 3D-printed occlusal splints for the conservative treatment of condylar fractures.</p> Methods <p>This was a retrospective observational case series study aimed to investigate the clinical outcomes of 3D-printed occlusal splints in the conservative treatment of condylar fractures. The patients were divided into pediatric, young adult, and adult groups according to age. The 3D-printed occlusal splint was secured to the maxilla for 2&#xa0;months. Patients were instructed to perform mouth-opening exercises daily. Mouth opening was recorded before treatment and at the 3-month follow-up. Data were statistically analyzed.</p> Results <p>After 3&#xa0;months of follow-up, no patients reported persistent pain, with mouth-opening and masticatory functions recovered. The postoperative mouth opening of all three groups was significantly greater compared with preoperative values, and the difference was statistically significant (<i>P</i> &lt; 0.05). All groups showed increased mouth opening. Regarding deviation of the mandible during mouth opening, the adolescent group showed significant improvement postoperatively (<i>P</i> &lt; 0.05), whereas no statistically significant difference was observed in the pediatric group and the adult group.</p> Conclusion <p>The use of a 3D-printed occlusal splint combined with mouth-opening exercises is a feasible approach for the conservative treatment of condylar fractures.</p>