Evaluation of posterior airway space after setback surgery by simulation

Area of Science:

• Biomedical Engineering
• Oral and Maxillofacial Surgery
• Computational Fluid Dynamics

Background:

• Mandibular setback surgery (MSS) is used to correct Class III skeletal abnormalities.
• Potential negative impacts of MSS on the upper airway (UA) are a growing concern.

Purpose of the Study:

• To compare varying degrees of MSS.
• To determine the maximum acceptable mandibular setback using Computational Fluid Dynamics (CFD).

Main Methods:

• Anatomical upper airway (UA) models were created from MRI data.
• Four models simulated different MSS amounts (0-15 mm) for Class III correction.
• CFD analysis modeled laminar, incompressible airflow with linear elastic soft tissue.

Main Results:

• A 15 mm mandibular setback (MSS) demonstrated statistically significant differences in UA airflow parameters (p < 0.05).
• No significant differences were found among models with less than 15 mm MSS (p > 0.05).

Conclusions:

• CFD analysis is a valuable tool for evaluating UA changes after MSS.
• 15 mm appears to be a critical threshold for mandibular setback surgery, beyond which significant UA airflow alterations occur.