How Does A Sliding Genioplasty Heal?

Q: Dr. Eppley, I am planning to have a sliding genioplasty surgery in order to increase my chin projection 1 cm horizontally. I know that average mandible symphisis thickness is around 1 cm.I have seen some photos from surgeries on internet operated with plates more than 10 mm which puts the lingual cortex of the lower downfractured chin segment in front of the upper fixed chin segments buccal cortex with less than 1-2 mm of horizontal space separating the upper and lower bone segments.İs that kind of advancement stable without the plate ?Can you explain how this two segments fuse? Will only the lingual cortex of the lower segment and buccal cortex of the upper segment fuse and leave the marrow parts exposed? I am very confused.Thank you for answering.

A:Your confusion is understandable as you are only considering the cental part of the chin where the lower segment can be advanced in front of the upper segment. But you are not considering the sides or wings of the advanced lower chin segment which always maintains contact with the upper bony edges. This is what makes the chin segment stable with only central plate and screw fixation. The center part may go on to heal albeit often with incomplete bony consolidation. (harmless but may contribute to deepening of the labiomental fold) Hence the benefits of allogeneic bone grafting of the bony stepoff.

Dr. Barry Eppley

World-Renowned Plastic Surgeon