Midface Protraction

Midface deficiency refers to a short upper jaw that results in a sunken cheek area, unsupported upper lip and a concave profile appearance, contributing to the appearance of a skeletal underbite. 

Skeletal underbites can be caused by a short upper jaw (midface deficiency), a long lower jaw or a combination of the 2 issues. 

It focuses on stimulating forward growth of the maxilla (upper jaw) to correct Class III skeletal discrepancies characterized by a deficient or retruded midface. This involves loosening and stimulating the circum-maxillary sutures and a protraction forces applied over a period of time to guide the forward and downward movement of the midface.

Expansion Devices:

Rapid maxillary expansion (RME) appliances are used in conjunction with midface protraction. Expansion helps to loosen the circum-maxillary sutures to increase the efficiency and effectiveness of protraction. Expansion also widens the maxilla to correct narrow upper arch and improves the airway. There are 2 ways of anchoring expansion appliances: (1) tooth-borne, (2) bone-borne.

Tooth-borne expansion appliances require firm and stable teeth to hold onto the appliances so that expansion forces can be transferred to the surrounding bone. Therefore, the best age for tooth-borne expansion appliances is 7-10 years old. Beyond 10 years old, baby teeth starts to get shaky and the expansion plate starts to loosen. No surgery is required. There are 2 types of tooth-borne expansion appliances: Fixed Hyrax Palatal Expander or Removable Invisalign Palatal Expander System.

For bone-borne expansion plates, these are anchored to the roof of the patient’s mouth (hard palate) via miniscrews. This transfers the expansion forces directly to the bone and will require a surgical placement.

Orthopedic Appliances:

Reverse-pull headgear

This is also known as protraction facemask, is a common orthopedic appliance used in protraction treatment. Protraction facemasks rests on the forehead and chin and serves as an anchor to bring the midface foreward via strong elastics to the intraoral expansion splint. This applies a forward force to the maxilla, promoting its growth and advancement. Treatment of protraction facemask is best done at the ages of 7-10 years old. Check out actress Dakota Fanning (when she was a kid) proudly modeling her Protraction Facemask at a talk show!

MiniPlates

Orthopedic traction of the midface via Bone Anchored Maxillary Protraction (BAMP) uses surgically inserted miniplates to serve as anchor points instead of teeth.

Examples of BAMP miniplants include Hugo De Clerck Cl III miniplates and Mentoplate system,

Benefits of BAMP:

• Ability to treat older children with underbites from age 11
• Less visible, therefore higher compliance rate
• Direct force application to bone for increased efficiency

BAMP using miniplates is a technique-sensitive procedure and our Orthodontic Team works with a select group of specialist oral maxillofacial surgeons for this procedure.

For tooth-borne appliances, the best age is 7-10 years old as baby teeth are still firm at this point. This serves as a strong foundation for tooth-borne appliances to transfer expansion and protraction forces to the surrounding bone.

Therefore for expanion splint and protraction facemask to target a short midface (maxilla), the best age is 7-10 years old.

For bone-borne appliances, age is less of a factor as these appliances are anchored directly to bone to transfer expansion and protraction forces. Bone anchored maxillary protraction devices such as Hugo De Clerck Cl III miniplates and Mentoplate system are best placed after the lower adult canines erupt, which is above 10 years old to avoid disturbing its development.

Corrects Skeletal Discrepancies:

Midface protraction addresses underdeveloped midfacial structures and aims to bring the upper jaw to its correct position.

Enhances Facial Aesthetics:

By promoting forward growth of the maxilla, midface protraction can improve facial profile and symmetry, reducing the prominence of the lower jaw. This helps to reduce and correct the ‘flatness’ of the midface and reduce the concave profile appearance.

Improves Occlusal Function and Speech:

Proper alignment of the jaws achieved through midface protraction treatment, corrects the underbite. This improves chewing efficiency, speech clarity, and overall occlusal function.

Opens the airway:

By expansion of the upper jaw and forward pull of the midface using protraction, this helps to open the airway and improve nasal breathing.

Prevents Surgical Intervention:

Early intervention with midface protraction in growing individuals may eliminate the need or reduce the magnitude of orthognathic surgery later in life by stimulating natural maxillary growth.

Age:

It is most effective in growing individuals with developing craniofacial structures, typically between the ages of 7 to 10 years old.

Dental health and stage:

Patients with poor dental health, lots of active decay, impacted upper adult teeth, missing baby teeth or shaky baby teeth may not be suitable for treatment.

Patient and Family Cooperation:

Successful midface protraction treatment requires consistent daily wear of orthopedic appliances and active patient and parent participation in treatment protocols. Parents must be patient and supportive of their child undergoing midface protraction. At least one parent or family member must be in charge of the expansion appliance to achieve good results.

Severity of Malocclusion:

The extent of midface deficiency and skeletal discrepancy will influence treatment outcomes and the duration of midface protraction therapy. Patients with anterior open bites, long face growth and sever lower jaw growth may not be suitable for midface protraction therapy.