The ornamental design for the marker label for 14 teeth, as shown and described.
FIG. 1 is a top plan view of my design for a marker label for 14 teeth;
FIG. 2 is a left side view thereof; the right side view is a mirror image; and
FIG. 3 is a bottom plan view thereof; and,
FIG. 4 is an upper side view thereof; the lower side view is a mirror image.
The broken lines in the drawing views are included for the purpose of illustrating a portion of the marker label that forms no part of the claimed design.