Simon's classification of malocclusion

Simon's classification of malocclusion,

n a classification of malocclusion in which tooth malpositions are related to three craniofacial planes: midsagittal, orbital, and Frankfort. Teeth too close to the midsagittal plane are in
contraction, whereas those too far away are in
distraction. Teeth too anterior to the orbital plane are in
protraction, whereas those too posterior to the orbital plane are in
retraction. Teeth too close to the Frankfort plane are in
attraction, whereas those too distant are in
distraction. See also malocclusion.