Background: The chin is one of the facial prominences and the most noticeable part of the lower jaw. Horizontal chin shortness has been recognized for many decades and has largely been improved through the use of synthetic implants. Placing an implant on the front edge of the bone is a simple and relatively uncomplicated method of horizontal increase.
Great results can be seen in many profile examples of chin implant augmentation but the chin and the face is more than just a side view. Patients see themselves more commonly in the front view and this perspective is becoming appreciated in chin surgery.The other dimensions of vertical length and transverse width have greater impact in the frontal view and also have an impact on chin appearance. Since a strong chin is a well recognized male facial characteristic, the chin should be enhanced from three-dimensional changes.
Case: This is a 28 year-old male who previously had an implant placed for a short chin. While there was an improvement, he was still not happy with the final appearance. He had an implant that provided 8mms of horizontal advancement. In assessing his chin with computer imaging, his chin was slightly short horizontally by 3mm to 4mms but was also vertically deficient by 5mm to 6mms. He also thought his chin was wide as well.
Given the needed changes to achieve a more pleasing three-dimensional change, it was decided that it could not be predictably done by a bigger implant. An implant could not provide enough vertical length improvement. An osteotomy was planned to not only make these desired changes but to replace what the existing implant has already created.
An intraoral approach was used to both remove the existing implant as well as perform the osteotomy. The existing pocket of the implant had already made most of the dissection needed for the osteotomy cuts. The capsule of the implant pocket was removed, exposing the raw bone surfaces. With a reciprocating saw an angled horizontal cut was made below the mental nerves. The chin segment was downfractured and then moved forward 11mms and opened up vertically 5mms. The backledge of the chin segment was put to the bone of the upper chin bone as a point of rotation for the vertical opening. It was secured using a custom-bent chin osteotomy plate. The chin implant was cut down in size and used as a fill for the step of the chin osteotomy. This was done to prevent further deepening of the labiomental crease.
Chin osteotomies create more swelling after surgery than implants. It usually takes about ten days after surgery until the chin returns to a more normal appearance and three weeks for most of the swelling to go away. While many patients can expect some temporary lower lip numbness, he experienced very little. The improvement in the side view shows the desired moderate horizontal advancement.
In the front view, however, the increase in vertical length is more apparent and gives the chin better facial balance. While it is often stated that the lower face should be 1/3 of vertical facial height, in men the lower facial height should be slightly greater than 1/3 of total facial height.
Case Highlights:
1) Changing the shape of the chin is more than just about horizontal advancement. Vertical length and width of the chin must also be considered for the best aesthetic result.
2) Mild vertical lengthening of the chin can be done with an implant that is secured on the inferior edge of the bony chin.
3)When more than a few millimeters of chin lengthening is needed, an opening osteotomy is best. It can be done to only lengthen the chin or bring it forward as well as with a vertical increase.
4)When a chin implant has failed to achieve the desired aesthetic outcome, a chin osteotomy can be considered which offers greater options for some chin changes.
Dr. Barry Eppley
Indianapolis Indiana