Dr. Lee Jinsoo's Plastic Surgery Essay 33 - Misconceptions and Prejudices of Double-Jaw Surgery

 

It seems that almost everyone is familiar with the term 'double-jaw surgery'. However, due to the proliferation of indiscriminate information about double-jaw surgery, many misconceptions and biases seem to exist. 

In this essay, we will take a detailed look at these misunderstandings and prejudices. 

1- Is Double-Jaw surgery a specific surgical procedure name? 

Double-Jaw surgery is not a specific surgical procedure name. It literally refers to surgery performed on both jaws. When translated to korean, '양 악' means 'bith jaws'. Thus, double-jaw surgery simply denotes a surgery conducted on both jaws, without specifying the exact surgical method.

while the general public may think of the lower part under the mouth when referring to the term 'jaw', anatomically, the term 'jaw' refers to the bone that includes the teeth. therefore, the upper jawbone containing the upper teeth is called upper jawbone (maxilla), and the lower jawbone containing the lower teeth is called the jawbone ( mandible). 

In practice, when performing double-jaw surgery, the procedures on the upper and lower jawbones are often quite standardized, making it unnecessary to use specific surgical names to convet the meaning.

2- Is Double-Jaw Surgery Cosmetic Surgery?

Double-Jaw surgery is not cosmetic surgery but rather orthognathic surgery, It falls within the category of "Orthoganithic surgery", which refers to corrective surgery for the jaws.

As mentioned earlier, the jaw includes the teeth, and if the jaws are not properly aligned, the upper jaw and lower teeth may not fit together well. This is known as malocclusion. Since the ability to chew is crucial for survival, correcting malocclusion is essential. Therefore, double-jaw surgery originally started as a procedure to correct malocclusion by adjusting the improper position of the jaws.

However, when the position of the jaw is corrected, it can also have a cosmetic effect. If the jaw's position is not correct, it can significantly impact facial aesthetics, leading to an abnormal facial shape outside the average range. Therefore, even though double-jaw surgery is primarily performed to correct malocclusion, it often results is a simultaneous cosmetic improvement as the jaw is brought into its normal position, In conclusion, while double-jaw surgery can produce significant cosmetic effects, these are secondary effects obtained while correcting the improper position of the jaw.

3-Can Double-Jaw surgery be performed by Single Surgeon?

Double-jaw surgery cannot be successfully performed by a single surgeon alone. For a successful double-jaw surgery, the collaboration between the operating surgeon and an orthodontic specialist, who assesses thr alignment of teeth, is crucial.

Double-jaw surgery aims to correct malocclusion, making the involvment of an orthodontic specialist who evaluates tooth alignment of the treatment and the completion of occlusion after surgery, the orthodontic specialist is involved in every step.

The closer the collaboration between the surgical specialist and the orthodontic specialist, the higher the level of success in double-jaw surgery. Therefore, choosing a surgical and orthodontic team with a long-term collaborative realationship is crucial for achieving optimal results.

4-Is Double-Jaw Surgery Only Performed in Cases of Malocclusion?

4. Not necessarily. While double-jaw surgery is predominantly performed is cases where there is malocclusion due to improper position of the jaws, it is not a strict rule.

In many cases, compensatory actions by the teeth can occur, preventing noticeable malocclusion even when there is an issue with the jaw's position, For example, individuals with 'long face syndrome' caused by an elongated upper jaw may not exhibit noticeable malocclusion, despite the characteristic facial features sush as difficulty closing the mouth

fully, excessive gum exposure when smiling, and muscle bulging at the jawline. However, correcting this facial type may require double-jaw surgery to reduce the length of the upper jaw.

Similarly, facial asymmetry resulting from the inclination of the dental occlusion plane often occurs without overt malocclusion. However, to correct facial asymmetry, double-jaw surgery may be necessary.

In summary, while malocclusion is a common indication for double-jaw surgery, there are cases where the procedure is performed for aesthetic or functional reasons, even in the absence of noticeable malocclusion.

5. 5-Is the Planning of Double-Jaw Surgery Solely Done by the Orthodontic Specialist?

For a successful double-jaw surgery, both the orthodontic specialist and the surgical specialist need to collaborate on the planning. The orthodontic specialist primarily deals with the patient's dental occlusion, while the surgical specialist is concerned with the overall facial aesthetics. Since the relationship between the upper and lower jaws determines occlusion, the orthodontic specialist mainly determines the relationship between the upper and lower jaws. Additionally, as the absolute position of the upper and lower jaws influences the facial asymmetry, the surgical specialist typically determines the absolute position of the jaws.

The optimal plan, resulting in both a good occlusion and favorable facial aesthetics, can only be achieved through close collaboration between these two specialists. The importance of a long-term collaborative relationship between the two specialists is underscored, as it is crucial for developing a well-considered plan.

6. 6-Is the Planning of Double-Jaw Surgery Based Only on Lateral X-ray (Cephalogram) Results?

For achieving optimal results in double-jaw surgery, planning should not rely solely on X-ray results but also consider the actual facial appearance.

Traditional planning for double-jaw surgery is primarily based on lateral X-ray results. Lateral X-rays provide consistent data on facial proportions, making it easy to compare with normal values and calculate differences. This helps in devising a relatively straightforward surgical plan based on these differences.

However, there are significant limitations to this approach. Lateral X-rays do not fully reflect the width and curvature of the face, leading to a diverse range of facial shapes even with similar lateral X-ray values. Additionally, the lack of representation of soft tissue conditions is a notable drawback.

To achieve a good plan for double-jaw surgery, it is essential to consider the actual face, including the soft tissues, and especially the frontal facial appearance.

REMA (Reverse Estimating method of Analysis) is an acronym for the 'Reverse Estimating Method of Analysis.' It is a method that determines the amount of bone surgery required to achieve the desired surgical outcome in the actual face. REMA is characterized by minimal errors in surgical outcomes. However, it requires a substantial amount of clinical data, making it challenging to implement in all hospitals.

7-Is Intermaxillary Fixation Essential After Double-Jaw Surgery?

Double-jaw surgery involves changing the positions of the upper and lower jawbones. In the surgical process, the new positions of the jawbones are fixed to maintain stability. Intermaxillary fixation is often performed to enhance the stability of these positions.

In the past, when fixation of the lower jaw was done using less robust methods, the principle was to perform strong and prolonged intermaxillary fixation. However, this approach resulted in significant discomfort for the patient due to the complete immobility of the lower jaw.

With advancements in techniques that provide strong fixation of the lower jaw, the necessity for intermaxillary fixation has significantly diminished. In some cases, intermaxillary fixation may not be performed at all.

Even with robust fixation, continuous external forces can cause the fixed bones to move. Therefore, entirely omitting intermaxillary fixation may have disadvantages in maintaining the stability of the fixed lower jaw.

A compromise is to use medical elastic bands for elastic fixation. This method allows for controlled movement and maintains the position of the fixed bones without the complete immobility associated with traditional intermaxillary fixation.