What Are Good Dimensions For My Custom Chin Implant?

Q: Dr. Eppley, I have a large square chin implant that was placed 6 months ago that I am not happy with. As the swelling went away it became apparent quite quickly that it was not whaI wanted. The improvement is too small and it has little if any square definition from the front view. I have a 3-D jaw model done after the implant which I have sent to you. I am requesting a chin implant that is 19 mm thick and 3 inches wide from the front. I know that the implant  is going  to be fitted directly on the bone which means that it is going to curve around the chin to the side.That being said the squareness and the size of the implant is going to deviate from the criteria that I am trying to achieve because as the implant proceeds backward from the mid point of the chin it is going to take a different shape and size. Knowing that to maintain the squareness of the implant along the 3 inch width we need to increase the size of the implant as it proceeds backward from the midpoint of the chin. Please tell what you think.

A: I have received your 3-D model of your mandible with the existing chin implant you now have. The current implant you have appears to be a Style I square chin implant of 9mms horizontal projection. It is significantly asymmetric due to placement with the right wing of the implant being very high and right up against the mental nerve location. 

As to your dimension request for a new custom chin implant, this needs to be carefully thought over as 19mms of horizontal projection is significant and would be roughly twice of that you have now. The 3 inch squareness width, or 7.5 cms frontal width, is considerable and is about a 3.5 cm width increase over the implant you now have. It would be unusual to need more than 5 or 5.5 cms in most men to develop a square chin look from the front. With such a wide frontal square width, this necessitates the need for a wide width around the corner of the implant as it transitions back into the side of the jaw.

I would be careful to oversize the implant and it is easy to do. It may seem that these dimensions are needed/desired, but it can be surprising as to how these translate to one’s appearance once in place due to the overlying soft tissue thickness. You do not want to end up with a ‘Jay Leno’ chin afterwards which is way too big and result in the need for revisional surgery. 

I would suggest some smaller dimensions to the custom implant, more like 15mm in horizontal projection and 5.5 cms square chin width.

Dr. Barry Eppley

Indianapolis, Indiana