Vertical Jaw Angle Implant Lengthening
Q: Dr. Eppley, In a previous email you said you wouldn’t drop the jaw angles any further down than 7mms for fear any muscle coverage problems which I understand– purely out of curiosity, is 7mm the maximum you can lower the jaw angles or does it depend on each individual patient?
A: The risk of masseteric muscle dehiscence exists any time you use an implant to extend the existing shape of the jaw angles vertically downward. There is no absolute number which has been determined to be ‘safe or not safe’ to do so. In my experience I have dropped it down 25mms and not seen any muscle problems and have dropped it down 7mms and have seen it. It is not a completely predictable effect. What I can say for sure is that the more it is vertically elongated the more the risk increases What I have also learned over the years is that the amount of vertical jaw angle lengthening that is really needed is often over predicted preoperatively. In essence a little bit goes a long way particularly when there is some width added also. Lastly, like all aesthetic surgery it is a balance between benefit vs risk. One must always be careful in the goal of the ideal result to not incur other aesthetic complications that are hard to fix. (and masseter muscle dehiscence is very hard to fix) It is always better to have 80% of the ideal result with no complications that it is to have 100% of the ideal result with complications.
Dr. Barry Eppley