RESUMEN
The aim of this report is to describe the design and steps for construction of a new design of mandibular occlusal splint, which was designed in a manner that facilitated the engagement of the bilateral undercuts usually located on the lingual aspects of the lower posterior teeth and alveolar processes. This occlusal splint was composed of two parts. The split design provided the flexibility needed to engage the deep bilateral undercuts located lingual to the mandibular posterior teeth and alveolar processes. The parts of the two splint segments were connected with flexible connectors made from cast Ti-6Al-7Nb, an alloy characterized by its high flexibility [for the first part], and wrought Cobalt-Chromium wire [for the second part of the splint]. These flexible connectors were expected to flex repeatedly each time the appliance was inserted or removed from its position without undergoing permanent deformation. The described occlusal appliance had the following merits. Since it had the ability to engage the bilateral undercuts usually located lingual to the posterior segments of the mandibular arch, this could abolish the need for any necessary block out and eliminate the spaces between the appliance and the oral tissues. Such spaces can be annoying for some patients because of the noticeable borders or trapped food when the appliance is used for eating. An undercut engagement also added to the stability and retention of the appliance