The ornamental design for an oralhygienedevice, as shown and described.
FIG. 1 is a perspective view of an oral hygiene device, the perspective view partially from the back of the oral hygiene device, partially from the left side of the oral hygiene device, and partially from the top of the oral hygiene device;
FIG. 2 is a front view thereof;
FIG. 3 is a back view thereof;
FIG. 4 is a right side view thereof;
FIG. 5 is a left side view thereof;
FIG. 6 is a top view thereof; and,
FIG. 7 is a bottom view thereof.
The broken lines in the figures are for the purpose of illustrating portions of the oral hygiene device and form no part of the claimed design.