a first dental arch configured to receive at least some of a wearer's teeth;

a second dental arch configured to receive at least some of a wearer's teeth;

two bodies coupled to the first dental arch, each body comprising:

a front stop;

a rear stop;

a threaded member coupled between the front stop and rear stop of the body and configured to rotate relative to the body; and

a hook comprising:

a threaded passage configured to engage the threaded member; and

an arm configured to engage a second dental arch;

wherein the hook is configured to travel between the front stop and the rear stop of the body in response to rotational adjustment of the threaded member to adjust the lower dental arch relative to the upper dental arch; and

two receivers coupled to the second dental arch, each receiver comprising a first rail configured to engage the arm of the hook of a respective one of the two bodies, the first rail being disposed exterior to an internal area defined by a span of the second dental arch;

wherein the two receivers are entirely disposed, with respect to each other, on opposite sides of a plane bisecting left and right halves of the second dental arch.