A Guide to the Different Facial Bone Surgeries

In the world of orthognathic surgeries, there are many acronyms and medical terms that can be confusing for patients when deciding which surgery will be right for them. This guide will help in clearing up some of that confusion.

ASO

Short for Anterior Segmental Osteotomy, ASO is the most common procedure for protruding mouth. Protruding mouth can be diagnosed by drawing a line from the tip of your nose to your chin on your side profile- those whose lips go beyond that line are likely to have protruding mouth.

ASO surgery fixes protruding mouth by extracting teeth and closing the resulting gap by cutting the bone and pushing it back.

Le Fort 1 Osteotomy

The upper jaw will either be rotated or moved up, down, left, or right via the Le Fort 1 Osteotomy or not moved at all depending on each patient. Generally, if the malocclusion is severe and the top incisors (front teeth) cannot reach the lower incisors, the upper jaw (maxilla) will be rotated. The length of the upper jaw will be shortened if the patient has issues with a "gummy smile" where they show too much of their gums when they smile.

The lower jaw (mandible) has two different procedures that the doctor will decide on based on each patient's needs. 

SSRO

Split Sagittal Ramus Osteotomy is the first, more common method used for the lower jaw during double jaw surgery. The difference between the two methods is where the bone will be cut. This method of surgery can be used for both underbites and overbites as it's possible to move the jaw in any direction. The bones are fixed to each other after the surgery through the use of titanium pins, allowing the patient to open their mouths immediately after the surgery.

IVRO

IVRO stands for Intraoral Vertical Ramus Osteotomy and is the second of the two methods used for the lower jaw during double jaw surgery. This method is preferred for those who have issues with their jaw joints or those whose nerves are too close to the surface within their bone and cannot undergo SSRO due to the risk of nerve damage. 

It cannot be used to bring the jaw forward in overbite patients. 

This surgery does not use pins to fix the mandible and instead requires IMF (Intermaxillary Fixation) to wire the jaws together as the bones heal. This means that the patient will not be able to open their mouths for about 2 weeks.

This might be off-putting for some, but for both SSRO and IVRO, patients are required to be on a liquid diet for 2 weeks.

We hope that this comprehensive guide has been helpful in enhancing your understanding of the different facial contouring surgeries we provide. We recommend talking to a professional to have your symptoms properly diagnosed and to have the right surgeries recommended to you.