Sorry for bringing up an old thread. I just want clarification on how my surgery will change my face. First off, please bear with me as my doctors don’t really share exact information with me and have been quite vague thus far as to the exact causes of my jaw problems.
It turns out I DO have an anterior open bite, which has now been revealed. The cause is posterior vertical maxillary excess, along with (I assume) anterior vertical maxillary deficiency (no tooth show at rest).
I am getting bi-max advancement of maxilla and mandible along with vertical reduction and advancement genioplasty of the chin.
Now, in regards to the open bite, will this correct itself on its own as it advances sagitally, I.e the anterior maxilla naturally comes down with advancement thus allowing for more tooth show and proper bite ?
Or will my surgeon have to impact the posterior max. IF SO, now that you know I have an open bite, how will this affect my mandible rotation ?
From what I understand, this will depend on how much is removed posteriorly and how much is brough down anteriorly. So probably the net affect would be 0, correct ?
Your presentation is somewhat confusing to me. You say you have you have anterior open bite and the cause is posterior vertical maxillary excess. OK, well PVME is treated with posterior impaction of the maxilla. But then you ask if your doc will have to impact the posterior maxilla.
If the cause of your jaw problems is posterior vertical max excess, PVME is treated with posterior impaction which is a clockwise rotation. If the cut out area is a wedge shape, the very front of the maxilla (where the 2 front teeth are) pretty much stays where it is and the maximum upward motion is to the very back of the maxilla. So bone removal is at minimum to front max where front teeth and at maximum where back teeth are. (d/dy where y is vertical distance decrease is function of horizontal distance traveled along the elongated wedge. Min at anterior maxilla. Max at posterior maxilla.)
Keeping in mind that the wedge section removal of the posterior impaction basically leaves the most anterior part of anterior maxilla pretty much where it was, what ever (front) tooth show you get will be a function of moving the maxilla 'forward' along the line (or plane) of the OP that is left after the wedge resection of the posterior impaction.
The angle of the OP left after the wedge section removal should describe a 'downward slope' (negative slope, DIAGONAL, which is normal for an OP to have). So 'forward' movement of the maxilla along this diagonal should kick up more tooth show. It will be a function of the inclination of the OP or 'steepness' of the diagonal. The steeper the inclination of the OP , the more tooth show you will get with 'forward' advancement along the new inclination of the OP (plane). [slope= 'hypotenuse'. Vertical displacement= hypotenuse X sin theta where theta is angle of inclination of OP]
Both the angle--number of degrees-- of Cw rotation and the number of degrees of the anterior open bite are needed to know in order to plug into the handy equation given prior: (CW rotation of mandibular plane) = (CW rotation of the maxilla) - (degrees of anterior open bite) for the net CW rotation. So a net rotation of the MP of 0 would only be when the number of degrees of anterior open bite=the same number of degrees as the CW rotation of the maxilla. But with no angle measures, the net rotation of the MP can't be estimated because all you know is what you don't know which is your docs aren't giving you much info other than that you're getting bimax and V reduction + advance for chin.
Is it possible they know you are doing this to look better but they are doing it because they see an indication to fix your bite and are wanting to withhold the planned displacement measures because there is chance the outcome does not meet up with aesthetic hopes for the surgery? I don't mean to make you paranoid but you should request a ceph displacement diagram where you can see the estimated prediction of the profile changes that go along with fixing the bite. Like is this private pay or insurance no charge?
