Chin implant removal - is it worth the unknown results?

I would say in most cases, when a chin implant is removed, the appearance of the chin will return to how it looked before the implant was placed.  I do not find that ptosis and sagging skin are common occurrences after removing a chin implant.  

Chin Implant removal information/and considerations: For the vast majority of chin implants, removal is straight  forward most commonly using the  same incision that was used to place it. The procedure is often done in the office with local anesthesia with or without some sedation, but also commonly done in the OR under IV sedation or general anesthesia per patient's and surgeon's preference.  Most implants are silicone and are not adherent so slip out readily. Medpor, also called PTFE, may have tissue ingrowth and can be a bit more involved but still can be removed in the same manner.  It is very helpful for your surgeon to  review your prior surgical records to know the size and type of implant used. This may be obtained by contacting your prior surgeon's office or OR facility and request your prior surgical records.
Expectations: if the chin implant was small and removed within the first few years chances are likely that you will return a similar size and shape as before. If the implant was small, the chin soft tissue usually shrinks back down without  sagging.  Often, there is still some gain once the implant is removed due to the scarring and capsule (lining your body makes around the implant) that gives some benefit. On the other hand a large implant placed many years ago, and other factors such as being elderly, having osteoporosis and perhaps smoking that can cause loss of underlying bone due to  bony erosion from the pressure of the implant. In this case  use of a natural filler such your fat or at times a bone graft may recommended for different reasons. Your surgeon may request a  Panorex or lateral cephalometric x-ray to see if this is the case.  Temporary fillers can also be tried such as Jeuvederm, Sculptra, Voluma, Volbella, etc. 
Most important of all make sure you pick a plastic surgeon with great expertise in #chinaugmentation and #chinimplantremoval. 
See the below link on how best to choose your surgeon.

You can have the implant easily removed and your chin should return to its pre-existing appearance. It sounds like your chin implant has migrated or was placed asymmetrically. I have removed several chin implants that have migrated following placement. I prefer to secure them by placing a bone screw through the implant.

 Hi, I have performed many facial shaping procedures, including Chin Augmentation with dermal fillers or silastic chin implants, for over 30 years.  If you have a silastic chin implant that was placed through a "submittal approach" as described below...the implant can easily be removed using the same incision in a few minutes under a local anesthetic.  When placed in this manner, there shouldn't be any chin ptosis however the chin will go back to its pre-operative weak projection.  A dermal filler can add forward projection to the chin.   If an intra-oral approach was used to place the chin implant, this cuts the superior muscle attachment which in my opinion can cause chin ptosis.  The implant is still best removed through a submental incision (under the chin) since this is the least invasive technique but some ptosis may result.  Chin ptosis is sagging of the chin muscle due to lack of bony support.  Dermal fillers can add forward projection but not " bone like support" to upwardly rotate the ptotic muscle.  In the end, you may require a chin tuck to reduce the ptosis followed by dermal fillers to add forward projection.  You have a third option, which is remove and replace the silastic chin implant (if the chin implant isn't in its proper location currently).  This option corrects the weak chin and any chin ptosis that would have resulted from simply removing the implant.  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".  The 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.  I perform chin implant surgery in 30 minutes or less, often using a local anesthetic alone.  Hope this helps.