frankfurtska ravan

standard horizontal plane at the level of the upper edge of the opening of the external auditory meatus (external ear opening) and the lower border of the orbital margin (lower edge of the eye socket), when the median plane of the head is held vertically

standardna horizontalna ravan u nivou gornje ivice spoljne strane slušnog kanala (spoljnog otvora uha) i donje granice orbitalne margine (donje ivice očne duplje), kada srednja ravan glave stoji vertikalno

standardna horizontalna ravan u nivou gornje ivice spoljne strane slušnog kanala (spoljnog otvora uha) i donje granice orbitalne margine (donje ivice očne duplje), kada srednja ravan glave stoji vertikalno