Chin augmentation using an implant is the common form of aesthetic facial augmentation. Putting an implant on the front edge of the chin bone has been done for over fifty years using a variety of materials. Silicone chin implants dominate the materials used for chin augmentation and are available in a variety of styles. The extended chin implants, or an implant style that has long wings that go back along the sides of the chin into the jawline, is the basic concept of most chin implant designs today.
While chin implants are effective for increasing the horizontal projection of the chin, they are not complication free. The most common adverse aesthetic issue with their use is malposition. With the extended implant design the risk of such malpositions are magnified as it doesn’t take much less than a perfect horizontal leveling of the implant to have wing asymmetry.
The longer wings of extended chin implants requires that a complete subperiosteal elevation of the tissues is done along the lower edge of the chin. If the tissues are not adequately released the wing of the implant will not be allowed to extend back as it was designed. Because the wing of these implants is very thin it is quite easy for their tips to bend with little detection that it has happened.
In executing the subperiosteal dissection along the inferolateral rim of the chin and anterior jawline, firm attachments are always encountered. These are the key anatomic structures that must be released for good pocket creation. These ligaments are the mental ligament and has been described as occurring about 1 cm to the midline and just superior to the inferior border of the mandible. Further back is the medial mandibular ligament located about 3 cms from the midline. (I prefer to call this the Ligament of Binder by the surgeon who first described its significance in surgically placing chin implants) A third mandibular osteocutaneous ligament also located about 5 cms to the midline and this has greater relevance in custom chin and jawline implants which go much further back along the jawline.
The release of these mandibular ligaments is the key in chin implant placement regardless of whether it is done through a submental or intraoral approach. Failure to do can result in chin implant malposition and external asymmetries.
Dr. Barry Eppley
Indianapolis, Indiana