Systems and methods for monitoring the status of oral appliances using sensors. One or more oral appliances may include one or more sensor receiver and emitter pairs configured to collect sensor data. Each sensor receiver and emitter pair may include a sensor receiver on or in a first portion of the oral appliance(s) and a sensor emitter on a second portion of the oral appliance(s), where each sensor receiver is configured to receive a signal emitted by a corresponding sensor emitter. At least one processor may be configured to determine the status of the oral appliance(s) and determine whether to modify a treatment plan implemented by the oral appliance(s) based on the status. The status may include one or more of: user compliance, condition of the oral appliance(s), and effectiveness of the oral appliance(s).