Điều trị lệch mặt do u xương sụn lồi cầu Management of facial asymmetry caused by condylar osteochondroma

A 29-year-old female patient presented with progressive facial asymmetry that had developed over approximately one year.

The timing of the deformity was an important diagnostic clue. Most developmental dentofacial deformities become apparent during growth. Therefore, when facial asymmetry develops or continues to progress significantly in adulthood, an underlying pathological process should be considered, particularly one involving the mandibular condyle and temporomandibular joint.

Progressive facial asymmetry in adulthood

Two important categories of condylar pathology are condylar resorption and proliferative or neoplastic lesions of the condyle.

In idiopathic condylar resorption (ICR), progressive loss of condylar volume occurs without an identifiable underlying cause. Predominantly unilateral involvement may result in mandibular asymmetry and deviation of the chin, whereas bilateral involvement can lead to mandibular retrusion and a skeletal Class II relationship.

Conversely, a proliferative lesion affecting one condyle may progressively alter the height and position of the mandibular ramus, displacing the mandible and chin toward the contralateral side. One of the characteristic lesions encountered in this region is an osteochondroma.

In this patient, imaging demonstrated a large mass arising from the condylar region, significantly distorting the local anatomy and displacing the condyle from its normal position within the glenoid fossa. This resulted in progressive deviation of the mandible and chin toward the opposite side.

As the deformity was continuing to progress and the patient had also developed pain, surgical intervention was indicated.

Surgical strategy

Several surgical approaches can be considered for condylar osteochondroma depending on the size, location, and extent of the lesion. These range from conservative tumor excision with preservation of the condyle to condylectomy, with joint reconstruction when required.

Another consideration is surgical access. Condylar surgery can be performed through an extraoral approach, which provides direct access to the joint region but requires consideration of an external scar and the important anatomical structures surrounding the surgical field.

During my surgical training in Japan, I was introduced to an alternative technique: simultaneous orthognathic correction and resection of the condylar lesion through an entirely intraoral approach.

This was the strategy selected for this patient.

Simultaneous tumor resection and orthognathic correction

The operation consisted of several procedures performed during the same surgical session.

A Le Fort I osteotomy was first performed to correct the maxillary occlusal cant.

In the mandible, bilateral sagittal split osteotomy (BSSO) was performed to reposition the mandible and correct the chin deviation.

The left coronoid process was then removed to provide intraoral access to the condylar region.

Two anchoring screws were inserted into the tumor to facilitate manipulation and control. The lesion was subsequently resected using a surgical saw in combination with a piezotome and removed through the intraoral approach.

Following tumor resection, the remaining superior portion of the mandibular ramus was reshaped to create a neocondyle, which was subsequently repositioned within the glenoid fossa.

This approach allowed us to address the condylar lesion, mandibular asymmetry, chin deviation, occlusal cant, and malocclusion within a single operation, without the need for an external facial incision.

Outcome

At two weeks after surgery, the facial asymmetry had improved substantially, with restoration of a more appropriate maxillomandibular and occlusal relationship. Postoperative occlusal guidance with a splint was continued during the early healing period.

Histopathological examination confirmed the diagnosis of osteochondroma, consistent with our preoperative assessment.

This case highlights an important principle in the evaluation of facial asymmetry: new-onset or progressively worsening facial asymmetry in a skeletally mature patient should not automatically be regarded as merely an aesthetic problem or a conventional malocclusion.

Identifying the underlying cause – particularly through careful evaluation of the mandibular condyles and temporomandibular joints – is essential before proceeding with orthodontic treatment or corrective jaw surgery.

My sincere thanks to all colleagues who contributed to the successful management of this challenging case.