I don't know about post-op, but I asked the same question about primary surgery. I could benefit from some chin widening at the time of my single jaw surgery, and this usually means filling in with either a graft or using an implant or other foreign material (hydroxyappatite, for example). Take a look at the link below where it explains that both implants or grafts can be used for this purpose.https://www2.aofoundation.org/wps/portal/!ut/p/c0/04_SB8K8xLLM9MSSzPy8xBz9CP0os3hng7BARydDRwN3Q1dDA08XN59Qz8AAQwMDA_2CbEdFAONltfE!/?showPage=redfix&bone=CMF&segment=Orthognathic&classification=95b-Chin,+Transverse&treatment=&method=Transverse+genial+hyperplasia&implantstype=Chin+osteotomy&redfix_url=1340282167441Now I asked a well-known surgeon and professor at a leading university this question (can PM you the name) and this is the answer I got from his staff:"Professor X does not use foreign material implants due to high complication rates.These complication rates include infection due to the foreign body, erosion of the surrounding tissue from the foreign body, unpredictability long term of the foreign material, hard scar capsules forming around foreign material and difficulty of removing foreign material gels and pastes. Professor X’s advice is to be very cautious."I hope this helps