A surgical tool or instrument having a plurality of depth stop positions, settings or locations, allowing for depth adjustment or a limitation of the allowable extension of a working tool coupled to or used in combination with the instrument. In example forms, an appliance or mouthpiece provides a guide to retain the surgical instrument to a particular orientation, and a stop member coupled to the tool or instrument in at least one of the plurality of depth stop positions, settings or locations determines the extension of the working tool therein.