Augmentation by an oblique sliding genioplasty is a highly successful procedure as it stretches out the overlying soft tissue chin pad. However when trying to do the same in reverse, or in any form of intraoral bony genioplasty where bony support is lessened (shaving, t-shaped genioplasty, reverse oblique osteotomy) the risk of soft tissue problems appearing afterwards is significant.
In the August 2021 issue of the journal Plastic and Reconstructive Surgery an article on this topic was published entitled ‘A new Concept of Narrowing Genioplasty: Home Plate-Shaped Sliding Osteotomy’. In this clinical paper the author reviews his 8 year experience with almost 120 patients with a new type of narrowing genioplasty. In this type of chin osteotomy a horizontal cut as made below the apices of the anterior teeth and then vertical line cuts down through the inferior border medial to the mental nerve foramen. (box shape) This permits the pedicle bone flap to be repositioned inferiorly 3, 4 or 5mm and secured with small plates and screws. Oblique bone segments are then were removed inferiorly from the repositioned bone on each side to give the chin a V-shape. The removed bone segments were then used to fill the bone gap as autogenous grafts. The soft tissue chin pad is resuspended to the midline plate before musculomucosal closure.
This type of inferior sliding genioplasty was uniformly successful in creating a more narrow and round chin in those who has prior broad/square chins. The complications encountered were minor and manageable. (6%) Temporary numbness of the lower lip, mentalis hyperactivity and one surgical revision for bony asymmetry was encountered.
The uniqueness of this type of narrowing genioplasty is that it combines a midline augmentation with a parasymphyseal reduction. The beauty of this concept is that it does not disrupt the bone to soft tissue support ratio, it merely changes the distribution of it. This potentially avoids the most common problem associated with any intraoral-based chin reduction/reshaping procedure…soft tissue excesses/deformities.
The one key anatomic feature that permeates all of the patient results shown is that their broad chin were also flat. That is probably the key factor in determining who is a good candidate for this type of narrowing genioplasty. Even though the vertical chin length increase is minor the patient has to be able to aesthetically handle/tolerate it.
Dr. Barry Eppley