The ornamental design for a scalp-treatment apparatus, as shown and described.
FIG. 1 is a front view of a first embodiment of a scalp-treatment apparatus;
FIG. 2 is a back view thereof;
FIG. 3 is a right view thereof;
FIG. 4 is a left thereof;
FIG. 5 is a top view thereof;
FIG. 6 is a bottom view thereof;
FIG. 7 is a perspective view thereof;
FIG. 8 is an enlarged view taken along the lines shown in FIG. 3; and,
FIG. 9 is an enlarged view taken along the lines shown in FIG. 6.
The broken lines shown in FIGS. 2-9 immediately adjacent to the shaded areas, represent the bounds of the claimed design, the bold dash-dot lines in a rectangular configuration represent the boundaries of the close-up sectional views in FIGS. 8-9 and all other broken lines shown in FIGS. 1-9 illustrate scalp-treatment apparatus that form no part of the claimed design.