weird. it's like drawing as though one of the axis is inverted.
try, as the first transform
d3d_transform_add_scaling(1,1,-1);
then your rotations... d3d_transform_add_rotationx/y/z....
then your translations... d3d_transform_add_translation...
then d3d_model_draw...
assuming the back to front of the head is layered on the zaxis.
you can also as mentioned, use another projection to fix this. if the aspect ratio is negative, that would also flip the vertices around