Background <p>Digital technology has been applied in the field of oral surgery. In this study, the efficacy of custom-made surgical guides for the removal of supernumerary impacted teeth in the maxilla was investigated.</p> Methods <p>The surgical guides were designed with access holes and rods that corresponded to the positions of the impacted teeth and the direction of the approach. The biocompatibility of the 3D-printed materials was first assessed in vitro. The efficacy of the printed surgical guides was evaluated in an in vitro experimental model study performed by 32 oral surgeons on 3D-printed maxillary models to evaluate various surgical parameters and complications, and a clinical observation study of 30 patients.</p> Results <p>The 3D-printed materials demonstrated excellent biocompatibility when they were fabricated according to the manufacturer’s protocol. In the in vitro study, the guides did not significantly reduce the extraction time or bone removal volume compared with those of the control group. However, they effectively prevented mispositioning of bone removal sites and reduced the incidence of root damage. Clinically, all surgical guides resulted in safe and precise bone removal without major complications.</p> Conclusions <p>The benefit of the surgical guide system used in the present study showed limited, but it might minimize complications and enhance the safety during supernumerary impacted tooth removal.</p>