Cheek implant removal: is the skin separated from the bone during implant insertion? Does it reattach at all?

Cheek implants are generally placed directly on the bone through an incision made beneath the upper lip. The implants are placed in a pocket beneath the skin, fat, muscle and periosteum and are sometimes secured with sutures, bolsters or titanium screws. The skin, fat, muscle and periosteum are maintained as a composite unit - these tissues are not separated from each other during the procedure.  Only the periosteum is elevated.
When an implant needs to be removed, it is done so through the same surgical approach. Afterwards the periosteum will re-attach to the cheek bone. While there is generally not a big risk of sagging afterwards, modest changes are theoretically possible depending on how strongly the periosteum attaches to the bone. Some stretching or thinning of the soft tissue of the cheek is also possible if an implant has been in place for a long time. However, most patients make a small amount of scar tissue around the implant, so there is rarely a noticeable change in cheek volume when the implant is removed. Your question is a good one, however, because of a wide variety of variables it is hard to answer with any certainty.  Overall, the risk is not great. I hope this helps. My best. 

Hello raihi Particular cheek implants, like those constructed with silicone, don’t merge with tissue and can be removed. while other implants are merged with natural bone tissue and they therefore become part of the cheek structure.

 Hi, I have performed many facial shaping procedures using dermal fillers, silastic facial implants (cheek, chin), liposuction and/or facelifts for over 30 years.  Following my beauty principles, men look chiseled and handsome with angularity in the cheeks, chin and mandibular angles.  Non smiling photos of your face from the front and side would help in the evaluation.  The following procedures would create a more ruggedly handsome face.
Cheek augmentation with cheek implants to add angularity to the cheeks and mid face.  Liposuction can be combined to reduce any excess fat to further shape the cheeks and face.
Chin augmentation, using a chin implant, to add projection to the chin creating harmony and balance to the lower face.  I have performed many facial shaping procedures, including Chin Augmentation with dermal fillers or silastic chin implants, for over 30 years.  When the chin is weak, this creates an imbalance making the nose appear larger, the mid face top heavy, the lower face looks short, de-emphasizes the lips and allows early formation of a "double chin".  Proper placement of a silastic chin implant adds forward projection to the chin thereby creating harmony and balance to the lower face.  Using the same incision, liposuction can be performed to reduce the fat and further shape the neck.  Excess skin, from below the chin, can also be removed through the same incision.  I have found that placement of a silastic chin implant, through a small curved incision under the chin (also allows excess skin removal) to be very safe, quick, highly effective and far less invasive than a sliding genioplasty (requires extensive tissue dissection, bone cuts and placement of metal screws and plates to secure the cut bone segments).  I perform chin implant surgery in 30 minutes or less, often using a local anesthetic alone.  In my opinion, you are a good candidate for chin implant surgery.  
Augmentation of the mandibular angles using a dermal filler (jaw implants have too many unwanted side effects IMHO) to add volume, angularity and flare to the jaw line.
 Cheek implants can be placed using several different approaches but using a small incision on the inside of the mouth remains the "gold standard" and most accepted manner of placement.  This technique places the silastic "cheek implant" on the cheek bone itself below the tissue covering of the bone (periosteum) in what is called an "implant pocket or space".  The tissues are closed in layers from the inside outward and a double water tight closure is done along the incision line.
 I have placed silastic cheek implants for 30 years in military, SWAT, LE, professional fighters, as well as actors and many regular people who are active.  When placed below the covering of the bone and when the layers of the cheek are closed from the inside out, there is no need for fixation screws or sutures in my humble opinion.  I do ask that all my cheek implant and chin implant patients sleep on a U-shaped pillow for 1 month following the surgery.  In addition, I have had the opportunity on numerous occasions to replace silastic cheek implants (placed by others) that had been screwed into the cheek bone.  During the replacement it was evident that the metal screws pushed right through the soft implant as it was tightened down on the hard cheek bone.  Which makes perfect sense.  So in the long run, these fixation methods alone are no guarantee that the implant won't move.  Proper placement, proper implant pocket creation and meticulous closure of all the tissues layers is what is required in my humble opinion.  And yes, the periosteum (bony covering) very quickly becomes reattached to the underlying bone which helps secure the cheek implant from moving.
 In contrast, a sub-malar cheek implant is as the name applies placed below the cheek bone thereby being incapable of actually changing the shape of the cheek bone itself and since the implant isn't placed below the periosteum, the implant must be sutured to the tissues themselves which is why I do not use or recommend sub-malar cheek implants.  
Hope this helps.