FIG. 1 is a rear top perspective view of a lower dental impression tray, showing a first embodiment of my new design;
FIG. 2 is a front top perspective view of FIG. 1;
FIG. 3 is a rear bottom perspective view of FIG. 1;
FIG. 4 is a front bottom perspective view of FIG. 1;
FIG. 5 is a rear elevational view of FIG. 1;
FIG. 6 is a front elevational view of FIG. 1;
FIG. 7 is a right-side elevational view of FIG. 1;
FIG. 8 is a left-side elevational view of FIG. 1;
FIG. 9 is a top plan view of FIG. 1;
FIG. 10 is a bottom plan view of FIG. 1;
FIG. 11 is arear top perspective view of a lower dental impression tray, showing a second embodiment of my new design;
FIG. 12 is a front top perspective view of FIG. 11;
FIG. 13 is a rear bottom perspective view of FIG. 11;
FIG. 14 is a front bottom perspective view of FIG. 11;
FIG. 15 is a rear elevational view of FIG. 11;
FIG. 16 is a front elevational view of FIG. 11;
FIG. 17 is a right-side elevational view of FIG. 11;
FIG. 18 is a left-side elevational view of FIG. 11;
FIG. 19 is a top plan view of FIG. 11; and,
FIG. 20 is a bottom plan view of FIG. 11.
The broken lines in the figures depict portions of the upper dental impression tray that form no part of the claimed design. The dot-dash broken line represents a boundary of the claimed design.