Jaw forward – Class III skeletal simulation

Protruding Jaw, Skeletal Class III Malocclusion, or Mandibular Prognathism

All these terms refer to the same condition: a lower jaw that extends too far forward. This type of jaw alignment can cause the lower teeth to overlap the upper teeth, leading to issues with chewing and eating. Most of the time, this is due to an oversized or forward-positioned mandible. However, it can also result from a receding upper jaw (maxilla).

Common symptoms and concerns include:

• Difficulty chewing or breathing through the nose
• Unbalanced facial profile, low self-esteem
• “Bulldog” appearance, recessed upper lip, flared teeth
• Drooping nasal tip, protruding lower jaw or chin
• Temporomandibular joint (TMJ) problems—clicking, popping, jaw locking (trismus)
• Trouble swallowing, nighttime teeth grinding (bruxism)
• Premature tooth wear, increased risk of cavities, canker sores, and gum disease
• Speech difficulties, slurred or lisping speech

A protruding jaw can also affect other parts of the body:

• Neck pain, stiff neck, or torticollis
• Shoulder and back pain
• Migraines, dizziness, and ear ringing (tinnitus)
• Overall postural imbalance—spine, hips, knees, ankles

What causes a protruding jaw?

It may be due to muscle imbalances (too tight or too loose), or it can be inherited (true prognathism), as famously seen in the Habsburg royal family. If muscles are the cause, physical therapy or minor surgery may help. But if it stems from bone structure, surgery is typically required to reposition the jawbone. Trauma or arthritis can also cause the lower jaw to shift forward.

Sometimes, it only appears that the jaw is protruding, when in fact the dental arch is misaligned—a condition called proalveolia. In these cases, orthodontics may be enough. When caught early in childhood, orthodontic appliances can slow jaw growth. In more severe cases or in adulthood, surgery is often needed in addition to orthodontics, which can realign the teeth but not the bone.

Tooth misalignment may also result from:

• Missing teeth (causing neighboring teeth to shift)
• Nighttime grinding (bruxism)

How does jaw surgery work to move the lower jaw back?

The exact procedure depends on your anatomy. The surgeon will analyze X-rays to determine the best approach.

Lower jaw surgery (mandibular osteotomy)

In most cases of mandibular prognathism, the surgeon cuts the lower jawbone and removes a small section to reposition it. Titanium plates and screws are then used to secure the new position.

Upper jaw surgery (maxillary osteotomy)

If the issue is a recessed upper jaw (maxillary retrognathia), the surgeon may perform a Le Fort I, II, or III osteotomy to move and rotate the upper jaw forward. This may include adjusting the palate, nasal base, or facial midsection. The maxilla is then fixed in place with titanium hardware.

Bimaxillary surgery

When the discrepancy is more severe—such as a protruding lower jaw and a recessed upper jaw—the surgeon may operate on both jaws. This comprehensive procedure ensures proper alignment between the upper and lower dental arches.

All procedures are performed under general anesthesia. While same-day surgery is rare, most patients stay in the hospital for 1 to 2 days. Incisions are made inside the mouth, leaving no visible scars. Surgeons may use ultrasonic or rotary tools to make precise bone cuts. Absorbable stitches are used and may either dissolve or be removed.
Some surgeons use 3D scans and printed surgical guides for added precision during surgery.
It’s generally recommended to have this type of surgery while still young to prevent long-term functional and physical issues. Orthodontic treatment (braces, lingual braces, etc.) is often required before and after surgery.

How much does mandibular setback surgery cost?

Costs vary depending on the complexity of the case, the surgeon, clinic, and technology used. Surgery to correct skeletal Class III malocclusion typically ranges from $10,000 to $30,000. If a functional issue is diagnosed (difficulty eating, for example), the procedure may be partially covered by national health insurance and supplementary plans. Purely aesthetic cases are not reimbursed.

What’s the difference between jaw surgery and chin surgery (genioplasty)?

In genioplasty, the surgeon reshapes the chin by cutting a portion of the lower jawbone. In reduction genioplasty, only the tip is modified. In extended genioplasty (chin-wing), the entire lower border of the jaw is adjusted. This alters the patient’s profile but does not affect tooth alignment.

The Temporomandibular Joint (TMJ): a complex mechanism

The TMJ is actually a pair of joints working together on both sides of the face. Movements are complex, involving rotation, forward/backward motion, and side-to-side motion (called “diduction,” like when chewing gum). Several muscles play a role: temporalis, masseter, digastric, mylohyoid, medial and lateral pterygoid. For minor issues, physical therapy or osteopathy may help. An orthodontist can adjust tooth alignment. If these treatments fail, surgery may be necessary—on one or both jaws (bimaxillary surgery).

How to manage jaw pain without surgery?

If your oral surgeon determines surgery isn’t necessary, here are some helpful habits:

• Avoid thumb-sucking and other oral habits
• Reduce neck and shoulder tension (stress, cold air, poor posture)
• Stop chewing gum
• Use a night guard to prevent teeth grinding
• Don’t hold your phone between your shoulder and ear
• Do regular neck stretches and self-massage

Woman with a protruding jaw (mandibular prognathism / skeletal Class III malocclusion). Simulation based on a photo.

 

A forward jaw can cause emotional distress and low self-esteem, especially in children who may face teasing. It may give the impression of anger or unfriendliness, which adds to the psychological burden.

We offer digital simulations of jaw setback surgery. Upload your profile photo to see what results you might expect—and use this as a helpful visual when discussing options with your surgeon.