Can Jaw Angle Implants Be Placed Through External Scars Used For TMJ Joint Replacements?

Q: Dr. Eppley, I have a question about extra-oral placement of a vertical jaw lengthening implant and infection rates. I had a 7mm width jaw angle implant placed, which for my extremely short/stocky face with almost no ramus/mandibular distance from the earlobe made my face puffy and squirl like (i am a male). It got worse because my jaw joints over time degenerated and moved even more backwards and vertically, to the point I will be needing a total jaw joint replacement and removal of the jaw implants. My question is: is it possible to have a vertical lengthening implant after the jaw joint replacement. In theory in the pictures it looked like it should be possible, but the lack of room for screw placement is what bothers me, i have added photos of the joint replacement prosthesis. My second question is: intra oral placement risks infection, not just of the implant, but also the artifical jaw joint, which would be pretty bad. Would a extra oral approach significantly reduce the risk of infection? I saw some studies on hip and knee replacement giving a number of 0.3-1% infection rate which is extremely acceptable, would this number be comparable to a jaw implant placed extra-orally? Some sources ive found have stated that extra vs intra orally placement of chin implant is only 1% vs 2% risk, that barely seems to make a difference in route of placement. My last question is, would the jaw angle implant be delivered through a new scar, or would the same scar be opened up to place the jaw angle implant. 

A: I don’t think there is any question that if you had indwelling TMJ joint replacements with the external approach to put them there would be no reason why you would not use the existing external scars for jaw angle implant placement…which would appreciably lower the infection and make the recovery easier by staying out of the mouth. In addition custom jaw angle implants would be needed so they mesh with the lower end of the condylar prosthesis and better manage any asymmetries between the two sides which will inevitably be present.

Dr. Barry Eppley

Indianapolis, Indiana