An appliance for use in a method of reducing facial aging and/or oral parafunctional activity comprising two parts, each comprising a composite structure comprising: a first layer formed of a durable, resilient, elastomeric material comprising a cured thermoset rubber and which in use contacts the occlusal biting surfaces of the posterior teeth; and a second layer formed of a durable, non-deformable material having a softening point over 100° C. which provides a bite plate; wherein the second layer of each part is provided with a protrusion formed of durable, non-deformable material having a softening point over 100° C. which is positioned such that in use the protrusion extends from the surface above at least a part of the first and/or second molar teeth which are in contact with the first layer. A method of making the appliance, a kit of parts, and methods of use are also disclosed.