How great is the risk for bone resorption after Chin implant? Can it be avoided?

The resorption, if truly present, is only to a small degree and not progressive. The surgeons skill has more to do with proper size determination, precise placement, and avoidance of nerve injury. Good luck!

If your desired advancement/augmentation of chin is not enough with sliding genioplasty, don't use implants! do go for augmented sliding genioplasty with the use of bone grafts to increase the gain in lenght.

The concerns about so called chin implant 'erosion' are overstated and clinically irrelevant. Many chin implants will exhibit a small degree of settling into the bone that is both self-limiting and does not change in any visible way the long-term effects of the augmentation. It is not a progressive 'bone eating' process that will eventually result in loss of the complete augmentation effect.

 Bone is living tissue and  it remodels itself based on local pressure from placement of a chin implant. The amount of bone remodeling the we have noticed is only incidental  when removing at an old chin implant. It is only a couple millimeters at most. It does not affect the integrity of the mandible since the bone  is very solid and thick. For many examples of chin implants, please see link and the video below

 Hi, I have performed many chin augmentations using a chin implant over the past 30 years.  A silastic chin implant placed through a small, curved incision under the chin is very unlikely to cause significant bone erosion.  In fact, I believe that most of the XRay evidence is really slight bone growth stimulated underneath the chin implant and not true bone erosion.  While it always is a possibilty that some bone erosion will occur following a chin implant, this is very uncommon and can IMHO best be avoided by not placing implants with too much projection.  Hope this helps.  

The concern for bone absorption goes back to the 1960's when a report of X-ray findings was published. This radiological finding does not translate into clically significance. Very little projection is lost and tooth root damage has not not been reported. I would think a million chin implants with silastic have been done without a trend for problems related to those very old radiology findings.