Who Developed AOO?
The AOO procedure was developed by Drs. Thomas and William Wilcko, of Erie, PA in 1995. Thomas Wilcko is a Periodontist in practice for 25 years, and his brother, William Wilcko, is an Orthodontist in practice for 18 years. Both were interested in methods of growing bones called Distraction Osteogenesis and Regional Accelerated Phenomenon (RAP), and modified these methods to work orthodontically with limited trauma to the surgical site.
A Brief History of the Technique
Distraction osteogenesis was first used in orthopedic medicine in the early 1900s, but the method wasn’t widely employed until the 1950s, when Russian orthopedic surgeon Dr. Gabriel Ilizarov perfected the technique. Dr. Ilizarov often did bone surgery to correct deformities and repair defects in arms and legs. While treating a patient with a short amputation stump, Dr. Ilizarov performed an osteotomy – that is, he cut the bone, intending to lengthen it with a bone graft in the middle. He then put a metal frame around the stump, creating a gap (technically called a “distraction gap.” By chance, he discovered that new bone grew in the distraction gap, eliminating the need for the bone graft. Intrigued, Dr. Ilizarov researched the phenomenon and proved that stressing a bone increases metabolic activity and cellular generation, also known in orthopedic science as "bone remodeling," resulting in growth of new bone. The phenomenon was named Distraction Osteogenesis (DO) – growth of new bone by means of surgically "distracting" the bone.
In the early 1960s, craniofacial surgeons began using DO techniques to rapidly expand palates in growing patients. In the 1970s, the technique was introduced to jaw surgery. During the next two decades, interest in craniofacial distraction grew slowly and sporadic experiments were performed, mainly on dogs. In the early 1990s, the technique began to be more widely used on human patients with jaw defects. Meanwhile, distinguished orthopedist Harold Frost realized that there was a direct correlation between the degree of injuring a bone and the intensity of its healing response. He called this the Rapid Acceleratory Phenomenon (RAP). In RAP, there is a temporary burst of localized soft and hard tissue remodeling (i.e., regeneration) which rebuilds the bone back to its normal state.
As early as the 1950s, periodontists began using a corticotomy technique to increase the rate of tooth movement. An oral corticotomy is surgical procedure where cuts are made in the Aveolar bone (the bone surrounds and supports your teeth). In the 1990s, the Drs. Wilcko, using computed tomography, discovered that reduced mineralization of the Alveolar bone was the reason behind the rapid tooth movement following corticotomies. They used their knowledge of corticotomy, and their observations of RAP, to develop their patented AOO technique in 1995.
How Does AOO Work?
Unlike a usual corticotomy, AOO doesn’t just cut into the bone, but decorticates it – that is, some of the bone’s external surface is removed. The bone then goes through a phase known as osteopenia, where its mineral content is temporarily decreased. The tissues of the Alveolar bone release rich deposits of calcium, and new bone begins to mineralize in about 20 to 55 days. While your Aveolar bone is in this transient state, braces can move your teeth very quickly, because the bone is softer and there is less resistance to the force of the braces.
Research has shown that after the Aveolar bone heals and the teeth are in their new desired positions, additional Aveolar bone has formed. The Drs. Wilcko, and other researchers have proven that the aftermath of AOO is as stable and long-lasting as conventional orthodontic braces. (A dental student named S.S. Hajji did his Masters thesis at St. Louis University on a comparison of the techniques and found that results were statistically identical between AOO subjects and the conventional orthodontic treatment group).
So, after AOO, the Aveolar bone is apparently not only as strong as it was before the procedure (and your teeth held in it just as well), but there is actually more of it-- which is advantageous if your profile needs to be built up to improve your facial aesthetics.
How Long Does Total Treatment Take?
Most people who have undergone AOO surgery are in braces from three to nine months. Afterward, they are in retainers for at least six months, or longer.
How Much Does AOO Cost – and Is It Covered by Insurance?
AOO is typically about double the cost of a traditional orthodontic treatment. So, if traditional braces cost you $5,000 for two years of treatment, AOO would cost around $10,000 for a three to nine month treatment. Some fees go as high as $15,000. Those costs include the anesthesia, the surgery, and the orthodontic treatment.
Most dental insurance plans don’t cover AOO surgery, because, at the moment, it is viewed as a cosmetic surgery. For example, Delta Dental, one of the largest dental insurers in the US, does not cover AOO. However, you should check with your insurance plan before you make your final decision. Be sure to check your medical plan as well as your dental plan, because some types of dental surgeries or anesthesias are covered under medical health benefits.
If your dental plan covers braces, the orthodontic portion of the procedure (which is roughly half of the total cost) may be covered.
What Type of Doctor Does AOO?
AOO surgery can be done by an oral surgeon, a periodontist, an orthodontist, or any dental professional who is versed in oral surgery and has attended the two-day Wilckodontics course. Currently, approximately 300 dental professionals around the world are qualified to do the procedure; about 270 of them are in the US.
How is AOO Surgery Done?
AOO is an outpatient procedure done in the office of an oral surgeon or other dental professional trained in the technique. It takes between three and four hours, and is considered a minor periodontic plastic surgery.
Usually, your braces are put on a few days before you undergo the AOO procedure.
After receiving anesthesia, (either general or local, depending on you and the surgeon), the oral surgeon cuts flaps along the surface of your gums and behind your teeth, exposing the bone adjacent to your teeth. Using a surgical bur, the bone is scored. The surgeon then places a bone graft over the bleeding area. The grafting material is mixed with antibiotics to help prevent infection. According to Dr. Thomas Wilcko, who I interviewed as part of my research for this article, the surgery is not difficult for the periodontist or surgeon, but is a bit tedious, as repositioning of the soft tissue can be time-consuming.
"(AOO) is not as invasive as taking out teeth," Dr. Wilcko said. "There is some swelling and very little bleeding involved."
After the procedure is done, you are usually given a narcotic pain reliever or told to take acetaminophen (i.e., Tylenol). According to Dr. Wilcko, pain relievers like Ibuprofen (i.e., Advil) are not recommended, since they are NSAIDs (Non-Steroid Anti-Inflammatory Drugs). NSAIDs can interfere with the production of prostaglandin hormone in your body and slow down the bone growth process which is vital to AOO. In addition, NSAIDs given during the first 24 hours following trauma (surgical or otherwise) inhibit clotting. Therefore, you should not take NSAIDs on a regular basis before or after undergoing AOO surgery.
After the surgery, you will probably be in no shape to drive, so arrange for someone to pick you up at the surgeon’s office and take you home.
Recovery from AOO Surgery
Total recovery from the procedure takes seven to 10 days. You will probably experience some swelling and need to use ice packs. If you are given a narcotic pain killer, you can take it for up to a week post-surgery. The surgery usually does not result in facial bruising.
During this time, you also use a special prescription mouthwash, because you can’t brush your teeth. Most people get the surgery done on Thursday, and take Friday and the weekend to recover before considering going back to work or school. However, you may want to schedule an entire week off (or do it during vacation time), to ensure that you will be most comfortable. After all, if complications (such as infection) do occur, you probably won’t be able to go to work or classes. And you certainly can’t work, study, or drive if you’re taking a narcotic pain killer.
Orthodontic Adjustments After the Surgery
After you have fully recovered from the procedure, your orthodontist adjusts your braces about every two weeks. Depending on your case, you will wear braces from 3 months up to about 9 months. After the braces are removed, you must wear a retainer for at least six months (although longer is usually recommended).
The same types of braces and retainers are used in AOO as in traditional orthodontics, so you will have your choice of metal or ceramic brackets.
Interestingly, an Austin, TX orthodontist named Albert H. Owen III researched Invisalign treatment in conjunction with AOO surgery. He had some minor crowding in his mouth and had the procedure done on himself (how’s that for dedicated research?!)
After surgery, he used Invisalign appliances to move his teeth. He reported his findings in the Journal of Clinical Orthodontics in June, 2001. Of course, the aligners were changed much more quickly than traditional Invisalign treatment (every 3 to 4 days instead of every two weeks). Dr. Owen was pleased with the result. He concluded that because the aligners had to be worn full-time, this technique required a high degree of patient compliance. He also said that because he didn’t have the AOO surgery done on his entire mouth (only on the areas adjacent to the crowded teeth), the "non-surgery" teeth hurt a lot more than the "surgery" teeth because of the force applied by the aligners. According to officials at Align Technolgies, Dr. Owen is the only dental professional (to their knowledge) that has used Invisalign after AOO surgery.
Patient Qualifications for AOO Treatment
AOO can be done on people of any age, as long as they have a healthy periodontal situation. According to Dr. Wilcko, the technique has been done on children as young as age 11 and on senior citizens as old as 77 (mainly as preparation for dental implants or devices).
You are not a candidate for this procedure if you have dental bone loss, periodontal disease, root damage or poor roots. In addition, if you have a disease such as Rheumatoid Arthritis which requires you to take regular doses of NSAIDs, you may not be a good candidate for AOO.
Dr. Wilcko says that the AOO technique can correct most of the orthodontic problems that are treated with traditional long-term braces. The only exception is a Class III condition, in which the lower jaw is too long relative to the rest of the face, and the chin protrudes. Class III cases have many physical constrains which may not lend themselves to AOO treatment.
Pros and Cons of AOO Surgery
You are in braces less time than traditional orthodontics
There is less likelihood of root resorption
After AOO, there is more bone to support your teeth and facial profile
History of relapse has been very low
There is less need for appliances and headgear (depending on the case)
In the eight years since AOO was first applied, the patients’ outcomes were good and have remained stable
The technique has its roots in proven orthopedic research and treatments
You can wear either metal or ceramic brackets
It is an expensive procedure, often not covered by insurance
It is a mildly invasive surgical procedure, and like all surgeries, it has its risks
You will experience some pain and swelling, and the possibility of infection
It is not for you if you take NSAIDs on a regular basis or have other chronic health problems
Some form of anesthesia must be used
You will probably miss a week of school or work
It does not lend itself to Class III malocclusion cases
It is not "pain free;" your teeth will still hurt when the braces begin to move them