Quantification of Mandibular Morphology in Pierre Robin Sequence to Optimize Mandibular Distraction Osteogenesis.

BACKGROUND

Mandibular distraction osteogenesis (MDO) is the primary surgical intervention to treat airway obstruction in Pierre Robin sequence (PRS). Current morphologic studies of PRS mandibles do not translate into providing airway management decisions. We compare mandibles of infants with nonsyndromic PRS to controls characterizing morphological variances relevant to distraction. We also examine how morphologic measurements and airway grades correlate with airway management.

METHODS

Patients with PRS under 2 months old were age and sex matched to controls. Demographic and perioperative data, and Cormack-Lehane airway grades were recorded. Computed tomography scans were used to generate mandibular models. Bilateral condylions, gonions, and the menton were identified. Linear and angular measurements were made. Wilcoxon rank sum and 2-sample tests were performed.

RESULTS

Twenty-four patients with PRS and 24 controls were included. Seventeen patients with PRS required MDO. PRS patients had shorter ramus heights (16.7 vs 17.3 mm; = .346) and mandibular body lengths (35.3 vs 39.3 mm; < .001), more acute gonial angles (125.3° vs 131.3°; < .001), and more obtuse intergonial angles (94.2° vs 80.4°; < .001) compared to controls. No significant differences were found among patients requiring MDO versus conservative management nor among distracted patients with high versus low airway grades.

CONCLUSION

Our study examines the largest and youngest PRS population to date regarding management of early airway obstruction with MDO. Our findings indicate that univector mandibular body distraction allows for normalization in nonsyndromic patients with PRS, and airway obstruction management decisions should remain clinical.