Three-dimensional computed tomographic evaluation of morphologic airway changes after mandibular setback osteotomy...

Area of Science:

• Oral and Maxillofacial Surgery
• Radiology
• Anatomy

Background:

• Mandibular prognathism requires surgical correction, often involving mandibular setback osteotomy.
• Changes in the pharyngeal airway and hyoid bone position are potential complications.
• Three-dimensional computed tomography (3DCT) offers detailed visualization of craniofacial structures.

Purpose of the Study:

• To evaluate morphologic changes in the pharyngeal airway and hyoid bone position following mandibular setback osteotomy.
• To assess the long-term stability of these changes.
• To correlate airway changes with the extent of mandibular setback and hyoid displacement.

Main Methods:

• 3D computed tomography (3DCT) scans were performed pre- and post-surgery on 30 patients.
• Two surgical techniques were analyzed: sagittal split ramus osteotomy and intraoral vertical ramus osteotomy.
• Pharyngeal airway dimensions and hyoid bone position were quantitatively measured and compared.

Main Results:

• A significant decrease in pharyngeal airway width (lateral and frontal) was observed three months post-surgery (23.6% and 11.4% reduction, respectively).
• Airway narrowing persisted at 6 months and 1 year, indicating potential irreversibility.
• Downward and posterior hyoid bone displacement occurred, correlating with the degree of mandibular setback.

Conclusions:

• 3DCT is a valuable tool for assessing airway morphologic changes after mandibular setback surgery.
• Mandibular setback osteotomy can lead to irreversible pharyngeal airway narrowing.
• Close monitoring of airway dimensions is recommended after this procedure.