Frankfurt horizontal plane

Frank·furt hor·i·zon·tal plane

(frahngkfurt hōri-zontăl plān) 1. A cephalometric plane that passes through the inferior borders of the bony orbits and the upper margins of the auditory meatus. 2. A reference plane in orthodontic diagnosis and treatment planning.[Frankfurt-am-Main Agreement, Germany, site of 1884 anatomy convention]