Stability and retention will be quantitatively assessed with jaw movement (MaxTraq motion analysis system, Innovision, Columbiaville, MI) and electromyography (EMG) (LabChart, ADInstruments, Colorado Springs, CO) data and force sensors. For position-stability assessment, maxilla, mandible and the splint will be simultaneously recorded from at least three sites to capture 6 degrees of movement freedom. Subjects will clench, grind, perform closed border movements and vacuous chewing (verified with EMG and force sensors). For retention assessment, subjects will perform a series of tests designed to dislodge the device, e.g., tapping, forced blowing, coughing, chewing on gum. Stability and retention indices will be created based on whether device movements vary independently of jaw movements and applied bite forces, and how force sensor output varies during dislodgement exercises. Deviations will be used to form standardized indices of stability and retention, with smaller values representing greater stability and retention. Note that a major part of the study will be to develop the appropriate methods to make these measurements, as it is not clear how this should be done ideally.