The chin is a unique facial area because its surface can have some very distinct features. Two types of topographic chin features can occur, dimples and clefts. While often confused they are different in shape. A chin dimple is located in the central chin pad and is a circular indentation. A chin cleft is a vertical indentation located more on the inferior aspect of the soft tissue chin pad.
One of the misconceptions abut chin dimples and clefts is that they are caused by an underlying bone defect. This is particularly believed in chin clefts where it is easy to image a midline cleft in the end of the chin bone to be responsible for the outer soft tissue indentation.
In custom jawline implant surgery one of the important preoperative needs is getting a 3D CT scan on which to design the implant. Since the vast majority of such patients are men, some of whom have chin dimples and clefts, this provides the opportunity to see what lies underneath these external chin features.
I have seen many chin clefts, that are externally fairly deep, that have no significant underlying bony shape deformities. Many have a round shape to the front of the chin.
Others have two prominent tubercles of bone on each side the end of the chin bone. But none had a very deep midline groove on the bone that resembles the degree of soft tissue indentation seen externally.
Interestingly I have seen midline bony indentations on chins that have no surface features. These are externally round chins whose shape does not match that of the underlying bone.
The relevance of this is when patients request to have a chin dimple or cleft created. It is evident that creating a chin cleft does come exclusively from making a midline groove in the bone or the implant. No matter how deep you make it that alone is not sufficient. It is helpful as part of creating it to give the overlying soft tissue a place to be inset. But these can features come from the overlying soft tissue and the external desired feature must be created in them by soft tissue removal.
Dr. Barry Eppley
Indianapolis, Indiana