Genioglossus and Genioplasty Advancement

This procedure is typically performed either at a surgery center or operating room under general anesthesia. All incisions are done transorally with no external incisions. The advent of CT imaging, computer planning, 3-D printing, and custom hardware have all made it easier to avoid complications such as dental injury and dehiscence of the genioglossus muscle.

Genioglossus advancement/anterior mandibular osteotomy

For a GA without genioplasty, also known as anterior mandibular osteotomy, the 3-D printed cutting guide is used to determine the pace of the muscle attachment to the inner table of the mandible (genial tubercle).

Once the guide is secured, a bicortical screw is placed through the advancement segment. A sagittal saw is then used to make the bicortical cuts through the mandible as marked by the guide planes. Typically, the segment is planned as a rectangular or trapezoidal shape. A spatula osteotome is used to complete the osteotomies. The segment is then drawn forward using a clamp placed on the bicortical screw. It is important that the screw used for traction engages both cortices so as to not separate the labial (outer) cortex from the lingual (inner) cortex.

Once the freed segment is pulled anteriorly, along with the genioglossus muscle, the fixation screw is removed. The labial cortex is then removed from the lingual cortex, which bears the attachment to the genioglossus. The lingual cortex is pulled anteriorly and fixated to the inferior border of the mandible using fixation plates and screws. Custom plates are very helpful for this, although add considerably to the material costs. The labial cortex that was previously removed may be secured to the osteotomy window to repair the defect. Alternatively, the rectangular lingual cortex can be rotated 90° in a coronal plane. The segment is secured to the bone superior and inferior to the bone window with fixation screws.

Genioglossus advancement with genioplasty

For GA with a genioplasty, also known as inferior sagittal mandibular osteotomy, the 3-D printed cutting guide is secured to the occlusal table. Predictive holes are then drilled and positional screws are used to secure the guide to the bone. After retraction of the mental nerves, a sagittal saw is then used to make the horizontal (transverse) osteotomy. While making the osteotomies, it is essential to have a good sense of the depth of the blade, to preserve the genioglossus muscle. Using computer guidance, the surgeon can be confident that the tubercle is included in the genioplasty segment.

Once the osteotomy is completed, the guide is removed. Once freed, the second, positioning guide is secured to the teeth and fixated to the genioplasty segment, using the same holes made previously. A pre-bent genioplasty plate, or a plate bent to the same shape can be used for fixation.