The ornamental design for a toothbrushstand, as shown and described.
FIG. 1 is a top perspective view of the toothbrush stand according to the invention;
FIG. 2 is a bottom perspective view of the toothbrush stand according to the invention;
FIG. 3 a top view of the toothbrush stand as shown in FIG. 1;
FIG. 4 is a front view of the toothbrush stand as shown in FIG. 1, which is identical to the rear view;
FIG. 5 is a side view of the toothbrush stand as shown in FIG. 1, which is identical to the other side view; and,
FIG. 6 is a bottom view of the toothbrush stand as shown in FIG. 1.
The broken-line disclosure is understood to illustrate portions of the article in which the claimed design is embodied, but which form no part of the claimed design.