Abstract: Adjustable hinge assemblies for partially or completely rotating an object joined thereto about an axis in specific, pre-determined increments defined by the interaction of ball pins and detents permit the adjustable hinge to retain an attached object in specific rotational positions until sufficient force is applied in the plane of rotation to overcome this interaction. In certain cases the object may be a door, window, baffle, or airfoil. Preferably, the adjustable hinges may be used as part of a sneeze guard assembly to hold a main sneeze guard pane whose angle can be adjusted to protect food from airborne contamination, such as in airborne saliva or mucus droplets. An optional tuck-away hinge pane prevents contamination of food from the ends of the sneeze guard assembly.