Q: Dr. Eppley, I have a question about possible chin implant erosion. I’m a female patient in my thirties. A few years ago I had a medpor chin implant inserted. I was wondering whether I could ask for your input since I understand you are one of the most prominent surgeons when it comes to both craniofacial as well as plastic surgery.
I had a cone beam scan performed a while ago because of some concerns about my teeth. There appears to be (what looks like) a ‘step off’ in the bone at the lower frontal teeth roots, but I’m not sure if I’m seeing this/interpreting this well – I might misinterpret the scan. Could this step off be caused by the chin implant? (It concerns a medpor chin implant). I drew a red arrow in the scan where I appear to see some kind of step off/change in the bone level. I appreciate your opinion. Thank you very much.
A: That stepoff you see is a classic example of chin implant settling (many refer to it as chin implant erosion which is an inaccurate term) This illustrates that despite the biologic nature of an integrated implant material like Medpor, implant settling can and does occur just like occurs in silicone.
By bone resorption I assume you mean periodontal (gum recession) and radiographic evidence of lower alveolar bone levels. Whether that is a function of the implant I would initially doubt it as the implant sits much lower than the root level. The usual symptoms would be more pain and tooth sensitivity not alveolar bone resorption. But to qualify that answer I would need to see a front view picture of the cone beam to assess the implant’s location under/over the tooth root levels.
Dr. Barry Eppley
Q: Dr. Eppley, I'd like to know based on your experience, how big of a chin implant would you consider as big enough to cause substantial amount of bone erosion From what I understand, chin implant of any size is bound to have some bone erosion to an extent whether or not it's substantially significant or just insignicant at all. Correct me if I'm wrong. When we talk about bone erosion, are we saying a 3-4mm bone erosion years after the surgery depending on the size of the implant? A surgeon suggested 1cm silastic chin implant and she said it's not considered big at all. I thought 1 cm is quite big isnt it so?
A: The issue of bone setting, not erosion, likely occurs with every chin implant to some degree. It is safe although speculative to say that the larger the implant the more settling into the bone that occurs. It is possible that implants of 1cm or more may have up to several millimeters of bone settling. While this is a frequently talked about phenomenon, I think it is clinically irrelevant. It has little impact on the aesthetics of the implant look and no other negative medical issues. It is only relevant if the implant is placed too high on the chin over thinner alveolar bone where implant settling into the bone may have adverse effects on the anterior incisor teeth. But a chin implant has no business being that high up on the bone anyway. It is also less of an issue today in anatomic or more extended implants where the pressure imposed by the implant on the bone is spread over a much larger area. In short, I would not concern yourself with this issue as I have never seen it to pose a problem when the chin implant is in good position over the lower basal bone.
Dr. Barry Eppley
Q: Dr. Eppley, I have a chin implant that was placed 35 yrs ago when I was 18. My dentist tells me that the bone has eroded behind the implant and that some teeth that are now moving in that area. It is a silicone implant. I know I have to get it removed but can I have a new chin implant or is that that? My surgeon said to take it out and consider a new implant when it is healed but I do not want another silicone implant and there’s a lot of info on the internet stating they too have had serious bone problems with silicone chin implants. Is this common? Thank you.
A: Never confuse passive implant settling with active erosion. Chin implants do not actively erode bone, they merely respond over time to the pressure of the overlying soft tissue and something has to give. This phenomenon can particularly be seen when the implant sits too high over the softer and thinner bone cortices in front of the roots of the mandibular incisor teeth. Obviously you have an old implant that is positioned too high, which is why it is closer to the tooth roots. A properly positioned chin implant sits down on the basal bone, some distance away from the level of the tooth roots. You simply could have the implant removed, an allogeneic bone graft placed into the cortical defect and a new chin implant placed in a lower proper position if desired. Whether that should be a silicone or Medpor implant is a matter of debate. I suspect the implant is small and, because it is positioned too high, probably has little actual influence on the horizontal projection of the chin.
> What has happened is a natural long-term process that is not reflective of pathology or some mysterious substance leeching from the implant causing this bone/radiographic reaction.
Dr. Barry Eppley
Q: I am 72 years old and I had a facelift and chin implant some 20 years ago. (I remember waking up and hearing Sammy Davis Jr. and that Jim Henson Died) Today they say the chin implant is causing erosion of my bone. I am scared and don’t even know where to start. My days of plastic surgeons have passed me as they have all retired. HELP!!!!!!
A: The phenomenon of chin implant erosion or settling into the bone is well known. It can be a natural event that occurs over many years with some chin implant patients. While called an ‘erosion’, that descriptor makes it sound like some aggressive process (implant eating into the bone) and that it is a serious problem. In reality, this phenomenon is nothing more than a normal biologic process to implants in certain locations known as pressure resorption.
You have to think of your body’s tissues as active and flowing, not forever stable and never-changing likes bricks on a wall. Your own bone is that way. Bone is dynamic and it responds to stresses by changing its structure. Calcium constantly flows in and out of bone. But a synthetic implant in the body does not change its structure, its is stable. Therefore, when a chin implant is put on top of the chin bone, it represents a stable non-changing structure between the bone and the overlying muscle. If the chin augmentation is significant, over time, the pushback of the stretched out overlying muscle causes long-term pressure on the implant. Since the implant’s structure can not change, only one thing can…the bone underneath. The pressure is relieved by the bone underneath resorbing allowing the implant to settle somewhat into the bone. While called erosion, this is simple and benign biologic process.
Most likely this was seen and diagnosed on a dental film. Unless the chin is causing you pain or the bone resorption is affecting your lower teeth with pain and sensitivity (both very unlikely), there is no reason to do anything with the chin implant. (unless you want to change it for cosmetic reasons) It is not an active process and the resorption is not ongoing. Once the pressure from the muscle is relieved, the bone resorption is not progressive.
Dr. Barry Eppley