Pharyngeal Airway Changes Following Mandibular Distraction Osteogenesis as Evaluated with Laryngoscopy

Purpose: Mandibular distraction osteogenesis (MDO) may improve airway grade in patients with Robin Sequence (RS), but little is known about the response of the oropharyngeal airway to the distraction process in cases of tongue base obstruction (TBAO). This study used drug-induced sleep endoscopy (DISE) to evaluate the impact of MDO on the oropharynx. Methods: RS patients with severe obstructive sleep apnea (OSA) were prospectively enrolled, and underwent DISE prior to MDO, and at the time of distractor removal. Laryngoscopy views, glossoptosis degree, polysomnography (PSG) results, oxygen saturations and airway measurements were compared pre- and post-MDO. Results: Twenty patients met inclusion criteria. At the time of distractor placement, a grade II laryngoscopic view was most frequently observed (63%), and one patient (5%) had a grade I view. Median obstructive apnea hypopnea index (OAHI) improved after MDO (49.1 [30.2-74.0] to 9.1, [3.9-18.0], p <= .001). Median oxygen saturation nadir also improved (preoperative 69% [60-76] to 85% [82-91], p <= .001). At distractor removal, mean laryngoscopic view improved (p <= .002) with no views that were grade 3 or higher. Median intraoperative oropharyngeal width improved, (3.1 mm [2.8-4.4] to 6.0 mm [4.4-6.8], p <= .021), as did median cephalometric anteroposterior oropharyngeal width (3.5 mm [2.7-4.1] to 6.3 mm [5.6-8.2], p <= .002). Conclusion: Following MDO, RS patients with TBAO have an approximate doubling of oropharyngeal width and an improvement in laryngoscopic grade. These findings likely contribute to improved oxygenation, OAHI and ease of intubation.