The ornamental design for a mandibleshield, as shown and described.
FIG. 1 is a front perspective view of a mandible shield showing my new design coupled to an optional helmet;
FIG. 2 is a front perspective view of the mandible shield shown in FIG. 1;
FIG. 3 is a rear perspective view thereof;
FIG. 4 is a front elevational view thereof;
FIG. 5 is a rear elevational view thereof;
FIG. 6 is a left-side elevational view thereof;
FIG. 7 is a right-side elevational view thereof;
FIG. 8 is a top plan view thereof; and,
FIG. 9 is a bottom plan view thereof.
The broken lines immediately adjacent the shaded areas represent the bounds of the claimed design while all other broken lines are directed to environment and are for illustrative purposes only; the broken lines form no part of the claimed design.