The ornamental design for an ultrasoniccutterhead, as shown and described.
FIG. 1 is a front view of the ultrasonic cutter head;
FIG. 2 is a rear view thereof;
FIG. 3 is a left side view thereof;
FIG. 4 is a right side view thereof;
FIG. 5 is an enlarged top view thereof;
FIG. 6 is an enlarged bottom view thereof; and,
FIG. 7 is a perspective view thereof. The broken lines shown in the drawings depict portions of the ultrasonic cutter head that form no part of the claimed design. The dash-dot broken lines define the bounds of the claimed design and form no part thereof.