What is

Anterior Segmental Osteotomy (ASO)?

Anterior segmental osteotomy is a modified surgical approach to treat maxillary protrusion.
A significant degree of protrusion can give a negative aesthetic impression.
Depending on the degree of protrusion, in mild cases, orthodontic treatment
may be enough to correct the protrusion but in cases where there is
structural bone involvement, surgery may be necessary.

Bimaxillary Protrusion

  • Bimaxillary protrusion refers to the protrusive dentoalveolar position
  • of the upper and lower dental arch that results in a convex facial profile.
  • It is a common characteristic found in Asians and can be categorized
  • depending on the its cause where treatment options differ.
  • Depending on the diagnosis and degree of protrusion,
  • treatment options are available from orthodontics to surgery.

Treatment options depending on Severity of protrusion

Mild Bimaxillary Protrusion

If the protrusion is less than 4mm

when examined from side view and are teeth related,

orthodontic treatment may be enough to

gain satisfactory results.

Moderate Bimaxillary Protrusion

If the protrusion is more than 4mm from side view and

is a structural bone related protrusion (A-point),

a surgical approach of anterior segmental osteotomy (ASO)

would be effective providing satisfactory results.

It usually involves the removal of 4 teeth

(upper and lower, left and right premolars) during surgery,

to allow the anterior bone to be pushed in and fastened.

Severe Bimaxillary Protrusion

In cases involving a long face,

asymmetry, protruding chin and short chin,

a delicate and complex surgical procedure is required.

It may include orthognathic surgery and

anterior segmental surgery

being carried out simultaneously.

Methods of Anterior Segmental Osteotomy

Anterior Segmental Osteotomy (ASO) Type 1

This is a surgical treatment option for protrusion of both the bones and teeth.

  • Extraction of upper and lower premolars
  • Fracturing and relocation of upper jawinto spaces remaining from premolar extraction
  • Fastening of the bone
Anterior Segmental Osteotomy (ASO) Type II

This is a surgical treatment option for protrusion of both the bones and teeth.

  • Fracturing of upper and lower jaw
  • Relocation of fractured upper and lower jaw
  • Fastening of the bone

Dr. K’s Guide to Anterior Segmental Osteotomy

A result that is suitable for the overall balance of the face shape is important for all surgical procedures.

Safety is of the highest priority for all surgical procedures however, it is also important to ensure
that facial balance is acquired for aesthetic procedures such as genioplasty.
For these surgical procedures, thorough research and planning should be carried out
as the surgeon’s experience and skill is critical in creating an overall balanced and natural result.
Accurate analysis and diagnosis of the thickness and condition of the bone is essential
in performing precision surgery in minimal time.

Dr. K has both the experience and skill to promise a safe and satisfactory result.

Before & After