Can A Sliding Genioplasty Bring The Lower Lip Forward?
Q: Dr. Eppley, Part of my problem with my profile is my lower lip is too recessed as well. Can the sliding genioplasty address the lower lip recession as well? The attached pictures show what could be accomplished with only a modest amount of vertical lengthening. The lower lip advancement should be considered when deciding how much horizontal projection to give. I saw this video and the surgeon in this video said the labial mental fold would appear less with sliding genioplasty because you are bringing it forward and down instead of just forward as in a chin implant. Will the lower lip move forward as well in sliding genioplasty?
I provided a link showing that I would like the osteotomy cut to reach more posteriorly just underneath the nerve to reach farther back to give a more broad appearance. See 1:19 in the video. I would also like the cut made in such a way that there is continuity in the bone. You can also come up more so it’s a few millimeters below the tooth root. I’m not sure if the bracket’s you ordered are for a specific dimension. As far as specific dimensions I was thinking 8-9 mm vertical and 7 -8 mm horizontal.
A:It is clear that you have some basic and common misconceptions about what a sliding genioplasty accomplished. So let me provide you with some basic understanding of what the procedure does and does not do:
1) It will NOT bring the lower lip position forward. Lower Lip position is primarily controlled by the lower teeth. Thus the only procedure that will bring the lower lip forward is a sagittal split mandibular osteotomy (orthognathic surgery) which pulls the whole lower jaw forward with the teeth. A sliding genioplasty is a bone cut beneath the lower teeth which moves the chin bone but does not change the bite relationship or move the lower teeth forward.
2) The depth of the labiomental fold (better described as the labiomental sulcus not a fold) is controlled by the attachment of the mentalis muscle to the bone. Any type of chin augmentation procedure (implant or sliding genioplasty), by definition, moves the bone or soft tissue chin pad below forward BELOW the attachment of the mentalis muscle or below the labiomental sulcus. Thus any form of horizontal chin augmentation is goin to make the labiomental sulcus deeper. That is unavoidable. In the case of a sliding genioplasty which is also providing vertical elongation the deepening of the labiomental sulcus may be mitigated somewhat. (not made appreciably deeper) That being said what is going to happen in your case? Because of the chin bone movements it will probably not get any worse but I would not count on it betting better either.
3) When it comes to the osteotomy cut, I will make it as to what I know is best. Your key misunderstanding on the sliding genioplasty bone cut is that you must stay way below the mental foramen to avoid cutting the intrabony course of the nerve (and resulting in permanent lower lip numbness) and you must equally stay below the tooth roots enough to avoid creating permanent numbness of the lower front 6 teeth. But no matter how the osteotomy cut is done it will NOT make the chin wider. A sliding genioplasty that brings the chin forward and down will result in the chin becoming more narrow…this is unavoidable.
4) How much the chin bone can come forward and down will not be known until actually doing it in surgery. You have a naturally very small chin and the large chin implant has undoubtably caused some typical loss of 1 to 2mms of bone. While I agree that a total 8 to 9mm forward and perhaps equally vertically downward may be optimal, whether that can be safely achieved in surgery remains to be seen. You can’t just move the chin out in space, part of it must remain in contact with the bone above it to heal and avoid substantial bone resorption.
In conclusion you are under the illusion that a sliding genioplasty can do more that what it can really do. The purpose of the sliding genioplasty in your case, as opposed to going right to the entire custom jawline implant, is to lessen the implant load on the chin with the second stage custom jawline implant. It is not being done necessarily because it will create a better aesthetic result than the one stage custom jawline implant.
Dr. Barry Eppley