Le fort iii kết hợp le fort i và bsso trong điều trị thiểu sản toàn bộ tầng mặt giữa Combined Le Fort iii, Le Fort i, and BSSO for global midface hypoplasia

Skeletal Class III malocclusion commonly results from maxillary deficiency, mandibular excess, or a combination of both. In many patients, correction can be achieved using Le Fort I osteotomy for maxillary advancement, combined with bilateral sagittal split osteotomy (BSSO) to reposition the mandible and genioplasty when indicated.

However, Le Fort I moves only the tooth-bearing maxilla below the orbital level.

When the deformity involves not only the maxilla but the entire midface—including the nasal framework, infraorbital rims, and zygomatic region—advancing the Le Fort I segment alone may improve the occlusion while leaving a substantial part of the facial deficiency uncorrected.

This patient required a different strategy.

When Le Fort I is not enough

The patient presented with a skeletal Class III relationship associated with marked global midface hypoplasia.

The deficiency extended beyond the tooth-bearing maxilla to involve the nasal, infraorbital, and zygomatic components of the midface.

A conventional Le Fort I advancement could have improved the maxillomandibular relationship and occlusion, but the more superior midfacial skeleton would have remained retruded.

The treatment objectives therefore needed to be separated.

A Le Fort III osteotomy was used to advance the midfacial skeletal framework as a whole.

A Le Fort I osteotomy was then used to independently refine the position of the tooth-bearing maxilla and establish the desired occlusion.

BSSO was incorporated to position the mandible relative to the newly reconstructed maxilla.

How Le Fort III differs from Le Fort I

The Le Fort III osteotomy is performed at a substantially higher level than a Le Fort I osteotomy.

It mobilizes the midfacial skeleton through the nasofrontal region, orbital boundaries, zygomatic region, and zygomatic arches, allowing the central midface to be advanced as a single skeletal unit.

As a result, the procedure can modify not only the position of the maxillary dentition but also projection of the malar region, infraorbital skeleton, and nasal framework.

This is why Le Fort III becomes relevant in selected patients with widespread midface deficiency that cannot be adequately treated with Le Fort I advancement alone.

Combining Le Fort III and Le Fort I for independent control of the face and occlusion

One of the principal advantages of combining these two osteotomy levels is the ability to control the global midface and the tooth-bearing maxilla relatively independently.

The Le Fort III movement first establishes the desired position of the overall midfacial framework, restoring projection of the nasal–orbital–zygomatic complex.

The Le Fort I segment can then be independently adjusted to refine maxillary position and achieve the required relationship with the mandibular dentition.

BSSO is subsequently used to reposition the mandible.

The operation therefore becomes a three-level strategy:

Le Fort III — correction of the global midfacial skeleton.

Le Fort I — refinement of the maxilla and occlusion.

BSSO — correction of mandibular position.

This allows facial projection and dental occlusion to be treated as related but not identical surgical objectives.

Three-dimensional planning close to the skull base

Le Fort III osteotomy is technically demanding because the osteotomy lines are located close to important orbital, midfacial, and skull-base structures.

Precise determination of both the location and orientation of these osteotomies is therefore essential.

For this patient, the entire procedure was planned preoperatively in a three-dimensional virtual environment.

At the nasofrontal region, the osteotomy was designed at an appropriate level and trajectory to maintain a safe relationship with the anterior skull base. The remaining osteotomy lines were similarly adapted to the patient's individual skeletal anatomy.

Based on this plan, patient-specific cutting guides were manufactured to transfer the designed osteotomies to the surgical field.

Following mobilization and advancement of the midfacial segment, patient-specific positioning devices were used to assist in reproducing its planned three-dimensional position.

In an operation involving multiple osteotomy levels and independently mobile skeletal segments, control is required not only in the anteroposterior direction but also in the vertical, transverse, and rotational dimensions.

Coronal exposure and preservation of the hair-bearing scalp

The superior component of the procedure was approached through a coronal scalp incision.

This provides wide exposure of the frontal region, nasofrontal area, lateral orbit, and zygomatic arches while allowing the final scar to remain concealed within the hair-bearing scalp.

In this patient, complete shaving of the scalp was not required.

Mechanical edge control was used during the scalp incision to assist hemostasis while limiting direct thermal injury from electrocautery near the incision margins and adjacent hair follicles.

During postoperative healing, hair continued to grow through the scar region, making the incision increasingly inconspicuous as the hair lengthened.

Early postoperative result

The combined Le Fort III, Le Fort I, and BSSO procedure was completed in approximately four hours, with estimated blood loss slightly above 300 mL.

At one month after surgery, postoperative edema was still present, but improvement in midfacial projection was already evident.

The nasal, infraorbital, and zygomatic regions had been advanced together while the maxillomandibular relationship was simultaneously reconstructed.

The coronal incision healed well, with preserved hair growth across the scar region.

Matching the osteotomy level to the level of the deformity

This case illustrates a fundamental principle in craniofacial surgery:

The level of the osteotomy should correspond to the level of the deformity.

When the deficiency is limited primarily to the maxilla, Le Fort I advancement may be sufficient.

When the entire nasal–orbital–zygomatic complex is retruded, however, repositioning only the tooth-bearing maxilla cannot fully correct the facial deficiency.

In appropriately selected patients, combining Le Fort III with Le Fort I allows the surgeon to advance the global midface to the desired facial position while independently controlling the tooth-bearing maxilla to achieve an accurate occlusal relationship.

The case therefore demonstrates the value of planning orthognathic and craniofacial surgery around the three-dimensional architecture of the entire face rather than the dental arches alone.