As Pete C says ... no filter company will warranty an engine if the fitler is dented. Filter companies don't build filters with dents in the can.
What you need to consider is the impulse pressure with every start up of the motor. The lack of oil flowing, to a sudden burst of pressure "flexes" the filter can. This is not something you can visually see. Over time the flexing of the shell itself, where there is a dent in the shell regardless of it's location, can ultimately impact that dent to become a crack and leak oil.
In a lab with bigger filters, Cat, Cummins, Detroit Diesel, etc you can see the "baseplate deflection" which is where the oil hits the solid area of the baseplate as opposed to the holes that allows oil into the filter and when the filter is "pulsed" (simulating start up) you will see the filter try to come away from the base. The gasket keeps it sealed to the base.
However the filter shell sees this same sudden increase in pressure as well. Hence the potential problem with a dented can.
Filter companies have a lot of experience with these type "leaks"...
It's your nickle if you use a dented filter. If you're lucky and it doesn't leak, great. If it does......