A three-dimensional printing system includes a resin vessel, a support tray, a motorized carriage, a light engine, and a controller. The resin vessel has a lower side with a transparent sheet which provides a lower bound for photocurable resin contained within the vessel. The support tray has a lower face for supporting an object being fabricated. The motorized carriage is for supporting and vertically positioning the support tray. The light engine is for projecting radiation up through the transparent sheet to a build plane. The controller operates the motorized carriage and the light engine to fabricate the object. The object includes a vertical arrangement of dental arches suspended from the lower face and a plurality couplings that connect pairs of the dental arches.
