Do you want to learn more about jaw surgery?

We understand that helpful information can be hard to find.

This post provides illustrations and information regarding jaw surgery (maxillomandibular advancement, maxillary advancement and mandibular advancement).

The post was written by an Ear, Nose, and Throat (ENT) surgeon, trained in sleep surgery (included over 40 maxillomandibular advancements).

Maxillomandibular advancement showing the split after the maxilla (upper jaw) and mandible (lower jaw) have been cut and moved forward. The plates and screws are shown in blue. CamachoMD.com
Maxillomandibular advancement showing the split after the maxilla (upper jaw) and mandible (lower jaw) have been cut and moved forward. The plates and screws are shown with blue color.

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Summary for how jaw surgeries are performed step by step

Surgeries of the maxilla (upper jaw), mandible (lower jaw) and chin are referred to as jaw surgeries. Jaw surgery is performed in an operating room.

First, the patient is given general anesthetic medications.

Second, the patient is intubated through the nose (nasotracheal intubation).

Third, the maxilla and mandible are then wired shut (by using Erich Arch Bars or other wires).

Fourth, the bone of the maxilla is exposed and is then cut with a saw blade. Once the bone is cut, a bone-breaking device (curved osteotome), is used to fracture the thin bone located behind the maxilla (called pterygoid plates). The maxilla becomes mobile and can be moved. The maxilla is secured with plates and screws into the new position.

Fifth, the mandible is exposed and a saw blade is used to cut the bone. Bone splitting tools (osteotomes) are used to help finish the separation of the mandible so that there are three pieces (two side pieces and one front piece). The front piece of the mandible has the teeth, and it is repositioned so that the teeth are aligned with the teeth of the maxilla. Plates and screws are then used to secure the mandible.

Sixth, if the chin surgery is planned for at this point, then it can be cut and plates and screws are used to secure the chin into the new position.

How is jaw surgery performed step by step?

First, the consent form is verified. This form has the patient’s name, date of birth and/or another identifier such as the medical record number. It has the procedure and the location of the procedure listed out. Risks, benefits, and alternatives are included in the consent form.

The patient is taken to the operating room and is given general anesthesia via an intravenous (IV) catheter or a facemask or a combination of the two techniques.

The eyes are taped shut.

The patient is then intubated through the nose (nasotracheal intubation). During this process, an endotracheal tube is placed into the nose and travels down into the airway. This allows for ventilation during the procedure.

Once intubated, the nasotracheal tube is secured to the forehead with foam and the head is wrapped.

Next, the surgeon places an oral retractor into the mouth so that the mouth and teeth can be cleaned with an oral mouth wash solution.

The maxilla and mandible are then wired shut (by using Erich Arch Bars or other wires).

Hardware for wiring the jaw shut known as maxillomandibular fixation. CamachoMD.com
Hardware for wiring the jaw shut known as maxillomandibular fixation.

At this point, there are three possible surgeries that can be performed (one or all three) depending on the patient:

  • Surgery of the maxilla (upper jaw),[1]
  • Surgery of the mandible (lower jaw),[1] and/or
  • Surgery of the chin (sliding genioplasty or genial tubercle advancement).[1]

How is surgery of the maxilla (upper jaw) performed?

Mandibular advancement after the cuts were made (osteotomy). CamachoMD.com
Maxillary advancement after the bone cuts (osteotomy).

The surgeon pulls the upper lip forward and makes a cut on the inside. The bleeding is stopped by using electrocautery.            

The soft tissue cut (gingivobuccal incision) is made from the first molar tooth to the opposite first molar.

The cut extends through the soft tissue and the bone of the maxilla is exposed up to the level of the infraorbital nerve (this is a nerve in the front part of the cheek, under the eye) so that the bone can be cut.

A saw blade is used to make the cut.

The cut is made such that it is tapered from the middle part of the maxilla toward the outer part of the maxilla.

Sometimes a small wedge of bone is cut out so that there is more of a rotation of the lower jaw, which can be important in obstructive sleep apnea cases. This is known as the counterclockwise rotation.

Once the bone is cut, a bone-breaking device (curved osteotome), is used to fracture the thin bone located behind the maxilla (called pterygoid plates). This allows the maxilla to fractured downward and then it becomes mobile.[1]

The maxilla can then be moved to new location (advanced or setback) and then it is secured with plates and screws.

How is surgery of the mandible (lower jaw) performed?

Mandibular advancement after the cuts were made (osteotomy). CamachoMD.com
Mandibular advancement after the cuts were made (osteotomy).

The surgeon pulls the lower lip forward and makes a cut on the inside. The bleeding is stopped by using electrocautery.            

The soft tissue cut (gingivobuccal incision) is made far enough posteriorly to allow for a saw blade to be used for cutting the bone of the mandible.

After elevating the soft tissue and exposing the bone, a saw blade is used to make the osteotomy (bony cut).

The cut is made above the entrance of the inferior alveolar nerve (lingula).

Inferior alveolar nerve and mental nerve. The nerve enters the lower jaw (mandible) and exits through the chin (at the mental foramen). CamachoMD.com
Inferior alveolar nerve and mental nerve. The nerve enters the lower jaw (mandible) and exits through the chin (at the mental foramen).

The cut on the bone is brought forward such that the mandible can be moved forward appropriately.

Bone splitting tools (osteotomes) are used to help finish the separation of the mandible so that there are three pieces (two proximal pieces (side pieces) and one distal piece (front piece)).

The front piece of the mandible has the teeth, and it is repositioned so that the teeth are aligned with the teeth of the maxilla. Plates and screws are then used to secure the mandible. Plates and screws are then used to secure the mandible into the proper position.[1]

Maxillomandibular advancement showing the split after the maxilla (upper jaw) and mandible (lower jaw) have been cut and moved forward. The plates and screws are shown with blue color. The inferior alveolar nerve is shown in yellow. CamachoMD.com
Maxillomandibular advancement showing the split after the maxilla (upper jaw) and mandible (lower jaw) have been cut and moved forward. The plates and screws are shown with blue color. The inferior alveolar nerve is shown in yellow.

How is surgery of the chin (sliding genioplasty or genial tubercle advancement) performed?

Genial tubercle advancement with a side view with a screw holding the bone segment into position and a green arrow pointing to the cut bone. CamachoMD.com
Genial tubercle advancement viewed from the side. Note there is a screw holding the bone segment into position and a green arrow points to the cut bone.
Sliding genioplasty. In this case, the cut of the bone included the genial tubercle. There are plates and screws in place, holding the bone forward. CamachoMD.com
Sliding genioplasty. In this case, the cut of the bone included the genial tubercle. There are plates and screws in place, holding the bone forward.

The bone of the chin (anterior mandible) is exposed by making the incision in the lower lip (gingivobuccal sulcus).

There are two main options for performing chin surgery, a sliding genioplasty (cutting front part of the lower jaw from one side to the other and then moving it forward) or a genial tubercle advancement (cutting a window in the chin and moving the bone forward).

If a sliding genioplasty is performed, then the bone is cut from one end of the chin to the other and the bone is advanced and plates and screws are placed to secure the bone into the proper position.

If a genial tubercle advancement is performed, then a rectangular or round osteotomy (bone window) is made in the chin so that the genial tubercle is moved forward. The genioglossus muscle of the tongue is attached at the genial tubercle, so the procedure moves the tongue forward.

Once the genial tubercle is moved forward, the outer part of the bone is removed and the inner portion that has the muscle attached will then be secured to the chin using a screw.[1]

Overall, care is taken during the surgery to help minimize bleeding.

Once the surgeon is confident that they have done all they can to ensure there are no bleeding areas, they will then pass a tube (orogastric tube) to suction out the contents of the stomach (which helps reduce nausea and vomiting).

The patient is then turned over to the anesthesia provider to allow the patient to wake up.

What are the Common Procedure Terminology (CPT) Codes for Jaw Surgeries?

Maxillary advancement:

  • 21141 (Reconstruction of the midface; single piece without bone graft)
  •  21145 (Reconstruction of the midface; single piece with bone graft)

Mandibular advancement:

  • 21196 (Sagital split reconstruction of ramus/body with internal rigid fixation)
  • 21199 (Segmental osteotomy with genioglossus advancement)

Government Disclaimer: The views expressed in this website are those of the author(s) and do not reflect the official policy or position of the Department of the Army, Department of Defense, or the US Government.

References:

1.         Camacho, M., et al., Large Maxillomandibular Advancements for Obstructive Sleep Apnea: An Operative Technique Evolved Over 30 Years. Journal of Cranio-Maxillofacial Surgery, 2015.