Downswung and Downgrown: The Difference Matters

[thecel]

A downswung mandible is when the mandibular plane angle (MPA) is steeply downslanted and the difference between the MPA and the occlusal plane angle (OPA) is small. In other words, both the jawline and the occlusal plane are nearly equally downslanting. The lower jaw appears “swung” down.

A downgrown mandible is when the MPA is steeply downslanted and the OPA is pretty straight. The difference between the MPA and the OPA is big.

With a downswung mandible, bimax with counterclockwise rotation (CCW) has a strong potential to ascend.

With a downgrown-not-downswung mandible, there’s not much room for CCW. The amount of CCW that makes the MPA ideal is very un-ideal for the OPA; it’d make the occlusal plane angle upward-slanted, which looks really ugly and uncanny.

How a too-CCW-ly rotated occlusal plane looks:

 

[HighIQ ubermensch]

good thread but edit it & add pictures for the low iq people here

 

[iblamemandible7]

True, you would just give yourself SFS if you fucked up the occlusal plane

 

[genetically fucked]

low iq people here

you?

 

[HighIQ ubermensch]

you?

not me I understand what he's saying

 

[thecel]

good thread but edit it & add pictures for the low iq people here

Downswung:

Downgrown (a little bit downswung) :