Facial balance is composed of aesthetic relationships between the three thirds of the face. Most commonly perceived from the profile view, there are various known projections of each facial third that makes it aesthetically appealing. When one of the facial thirds is out of balance it makes the other two–thirds of the face look larger and disproportionate.
Lack of adequate midface projection, or midface hypoplasia, occurs for a variety of reasons. Most commonly this occurs due to natural development and is more prone to occur in certain ethnicities. (e.g., Asians) But other causes include traumatic injuries as well as congenital facial birth defects. (e.g., cleft lip and palate) Lack of adequate midface projection can create a variety of clinical conditions such as negative orbital vectors, class III malocclusions and an overall flatter facial profile even in the face of a satisfactory bite relationship.
There are numerous surgical procedures that are designed to increase midface projection in selective areas. A LeFort I osteotomy moves the lower maxillary level forward. Cheek or infraorbital-malar implants increase fullness in the upper midface area of the inferior orbital rims and cheeks. Fat injections can be used to create a more complete midface augmentation effect but their take and persistence is highly variable.
Using an onlay bone augmentation approach, the custom midface implant can create complete middle third of the face projection. Made from the patient’s 3D CT scan, the custom midface implant provides projection from the infraorbtial rim down to the anterior nasal spine. Its design looks very much like a mask with larges holes made in it for the relief of the infraorbital nerves. The implant provides augmentation of every midface bony surface in a forward projecting manner. Its thickest part is usually around 7mm and that is around the nasal base. It becomes thinner as it progresses upward over the orbital rims.
The custom midface implant is placed through an intraoral maxillary vestibular incision. good cuff of musculomucosal tissue is left inferiorly. The implant is placed by cutting the infraorbital holes superiorly so that can fit around the nerve. Multiple 4mm perfusion holes are placed throughout the implant to allow through and through tissue ingrowth. The implant is secured into position using four 1.5mm screws.
The custom midface implant offers complete midface projection without affecting the bite since it is an onlay bone method. While it looks big and overwhelming on the 3D model, it is much smaller when placed onto and into the patient. It provides central augmentation of the midface without increasing the width of the cheeks. It effectively ‘pulls’ out the middle part of the face.
Dr. Barry Eppley
Indianapolis, Indiana