It is described an auxiliary structure (240, 440, 540) for treatment of at least one tooth (123) of an upper jaw (100) and/or lower jaw (120), the auxiliary structure comprising: a body (241), in particular comprising a plastic material the body having a lower surface (233) and an upper surface (235), which are defined based on a lower border (665, 765) of a lower volume (666) occupied by lower teeth of the lower jaw in a bite state and an upper border of an upper volume occupied by upper teeth of the upper jaw in the bite state, wherein the lower surface (233) and/or the upper surface (235) comprises at least one recess (257) with respect to the lower border and/or the upper border, respectively, and/or a common annular edge (247, 251, 253, 255) limiting a through hole (249, 252, 254, 256) through the body (241).
