Genioplasty - 4 months post op. Unhappy with the result. My face is too long and pointy. (Photo)

Sometimes genioplasty like rhinoplasty takes more time to appreciate the final results. An advancement of 6mm is normal. I think that your chin "fits" your face and looks good. I would allow more time before suggesting any changes. It is possible to diminish the amount of pointedness by shaving the most prominent area without reversing the genioplasty. Remember, "the enemy of good enough is better"  Good luck

Your observations are not uncommon when the genioplasty does not properly 'blend' with the jawline behind. the net result is a more narrow look to the face and a longer look; despite the fact that the actual chin is not longer. The answer is to augment and taper the jawline behind the chin with material to subtly blend the chin and enhance the fullness/definition of the entire jawline.