Deep labiomental fold and curved chin after sliding genioplasty. Will this subside with more time? (Photos

Dear Number 23,Thank you for your photos.  It is unlikely the that your mentolabial crease depth will improve.  The stronger appearance of your crease is related to the amount of advancement of your chin and to a lesser degree the angle of the bone cut of your genioplasty.  "Reversing" your genioplasty will yield less predictable results.Earl Stephenson, Jr, MD, DDS, FACS

I perform regularly all kinds of genioplasties, not only sliding genioplasties but also one, two and three-dimensional augmentation and/or reduction genioplasties, plus other custom designs; in other words, I know well what I am talking about. 
With that said, your complication and your case is way clear. There are a few conceptual errors in the planning (not in the execution) of your genioplasty. Genioplasties are not-that-difficult to perform (stil they are) however become a real challenge in planning the procedure, its angles, the mm of increase/decreast, the synthesis, the donor sites, the grafting, the cuts, the overall facial and skeletal proportions, etc. Their versatility (of osseous geniplasties) make their unparalleled advantage and their awesome results, but also make a technical challenge (if not a nightmare for untrained surgeons) out of them.
If I had been your surgeon and based on your preop images I'd have suggested you the following 2 choices, for you taking the best fitting one:
-unidimensional sliding genioplasty: your chin shows slight shortfall of projection, therefore a SLIGHT anterior advancement would really benefit you
-two-dimensional augmentation genioplasty: your chin has short projection but, also, has moderately short vertical height if we consider your overall facial balance; this would be my preferred option for your face, however the simple sliding unidimensional increase is also an acceptable one
Seems your surgeon did not offer you these options, or if he did you took just the sliding unidimensional genioplasty; that's fine.
So, considering your chin is already short vertically... under NO circumstances the maneuvers performed on it should provide any kind of additional vertical shortening!!! >>> first error
And considering your chin's lack of anterior projection is slight, a great care has to be taken preoperatively not to incur in the dreadful chin overcorrection! >>> second error
As per the postop images and the x-rays it is clear the problem: your surgeon has performed and sliding genioplasty with an oblique cut, when this should have been fully or very close to a totally horizontal plane; he made it in 45º, so sliding the chin with such angle, obviously, produces:
-massive vertical shortening
-a push-up effect of the mental tissues and a pinching of the labiomental fold
Both former effects do deepen the labiomental fold, and in association with the excessive advancement applied make your chin a witche's one, too prominent, too short vertically and too deep the mental crease.
Let me point out one of the possible explanations for such poor design of your geniplasty: the still hard to understand use and abuse of plates and screws for genioplasties... plates and screws allow no verstility, they can't (or can barely) be graded or calibrated in terms of how many mm we advance or shorten the bone, pluse another major drawbacks (like often requiring late removal, infections, disturbances, etc.); that's why the advocacy in favor of the traditional steel wiring, which I am personally using 15 years ago without complications (still no one of my geniplasties returned for wiring removal, as example).
Note: you are luck you did not lose some teeth, your screws are really close the their roots...
What is your solution now? This is my plan and proposal:
-remove plate and screws carefull
-re-fracture through the same osteotomy line
-deproject part of the advancement created in the previous surgery
-and insert and interpositional bone graft to lengthen vertically your chin with 2 goals: releasing the pinching effect of deep labiomental fold + gaining 4-5 mm of vertical height at your chin so it fits your new facial balance
Yours is a really challenging and professionally interesting case of revision genioplasty, however only successfull in very experienced hands. 
I would be happy to provide additional examination and advice if you feel interest.
Feel free to contact me for any additional information.