Surgery First Orthognathics
11th January 2021
Categories: Orthognathic Surgery
The idea of ‘surgery first’ orthognathic treatment is not a new one. In fact, orthognathic surgical procedures were performed a long time before orthodontic treatment was invented. The ultimate goal of orthognathic treatment is to create a balanced and symmetrical facial profile with a stable and well aligned dental occlusion.
Timing of Surgery
- Surgery First – before any orthodontics
- Surgery Early – minimal orthodontics
- Surgery Late – conventional timing
- Surgery Last – previous orthodontics
- Surgery Only – no orthodontics required
In patients with poorly aligned jaws, the discrepancy can be too severe to improve the bite, profile and symmetry with orthodontic treatment alone. Therefore, joint treatment with orthodontics and surgery was devised.
In order to gain the most stable and aesthetically balanced profile, modern orthognathic treatment usually encompasses a period of presurgical orthodontics followed by a surgical procedure. The advantages of following this approach are a predictable and controlled approach to treatment especially surgical planning and execution.
Unfortunately, there are also disadvantages to this approach:
- The overall treatment time can be very long (some patients require orthodontic treatment for up to 2 years before being ready for surgery)
- The orthodontic treatment can cause damage to the teeth (most importantly root resorption)
- The patient’s profile will typically worsen as the compensated occlusion is decompensated in readiness for surgery
- If the patient decides not to proceed with surgery following presurgical orthodontics, the occlusion and profile may end up worse than at the start
As a result of these concerns, several surgical teams have suggested undertaking surgery earlier in the treatment pathway; either with no presurgical orthodontics (surgery first) or minimal presurgical orthodontics (early surgery) . There are a number of obvious reasons why this may desirable.
- By putting the jaws in the correct position, it allows a rapid improvement of the patient’s profile rather than worsening the profile over a period of years.
- The overall treatment time can be reduced by many months
- The risk of orthodontic root resorption is decreased.
Two big technological advances have allowed ‘surgery first’ treatment to thrive. They are :
- the development of titanium plating and fixation systems that can reliably fix and retain the jaws in a position that allows post surgical orthodontics to be carried out.
- Computer base planning based upon 3D scanning of patients. This allows the surgeon to accurately position the jaws according to computer modelling and reduces the reliability on the teeth to govern the final jaw position.
So why don’t all surgeons do surgery first?
There are a number of reasons why not all patients are suitable for ‘surgery first or early surgery‘ orthognathic treatment.
- Their teeth may have very severe crowding or malalignment
- The curvature of their teeth (Curve of Spee) may be too severe
- Their incisor teeth may be too proclined or retroclined (sloping markedly forward or back)
- The final occlusion or bite requires teeth to be extracted to achieve the best result
- Their palate is too narrow and the upper teeth require widening in order to achieve a good result
Even in cases where a surgery first approach may be possible, there are a number of potential problems. These include:
- The surgery has to be planned meticulously and performed perfectly. A small surgical error can lead to problems in achieving the desired bite.
- Predicting how the teeth (and therefore the occlusion) will react to the surgery can be difficult.
- The surgery may require a more complex osteotomy pattern than when the occlusion has been adjusted before surgery. Therefore, the chance that a patient will require a multiple segment osteotomy is higher in presurgical cases.
In summary, ‘surgery first or early surgery’ cases are possible and offer some distinct advantages to the prospective orthognathic patient. However, good case selection as well as surgical and orthodontic experience is vital to achieve a safe and reliable results.