Increased Distraction Magnitude Leads to Greater Reduction in the Apnea-Hypopnea Index in Infants With Robin Sequence

Upper airway obstruction seen in Robin Sequence (RS) is commonly treated with mandibular distraction osteogenesis (MDO). The purpose of this study is to evaluate the impact of distraction distance on sleep study outcomes in patients with obstructive sleep apnea (OSA) secondary to RS.

A retrospective cohort study was conducted for patients with isolated RS who underwent MDO at Children's Hospital Los Angeles between January 2006-September 2021. The predictor variable was distraction distance (maximal distraction using a 30 mm device vs sub-maximal distraction), and the primary outcome variable was OSA scores. Relationships between covariates, including demographic characteristics, preoperative sleep variables, and postoperative OSA outcomes using polysomnography, were also analyzed. Descriptive statistics and tests of statistical significance were performed using the Statistical Package for Social Sciences (SPSS) (version 28.0), including Student's t-test, proportions testing, multiple linear regression, and correlation analysis.

Seventy-one patients met inclusion criteria (39.4% female, 60.6% male). Average age at MDO was 3.0 ± 10.2 months. Fifty-six patients were distracted maximally with a 30 mm distractor, while the remaining 15 patients experienced shorter distraction due to distractor limitations (25 mm distractor), persistent infection or family request. Looking at absolute values of postoperative sleep study variables, there were no significant differences between patients who were maximally and sub-maximally distracted across apnea-hypopnea index (AHI), highest carbon dioxide, lowest oxygen saturation, and oxygen requirement. However, both cohorts demonstrated significant improvements in lowest oxygen saturation, AHI, highest carbon dioxide level, and highest oxygen requirement compared to their pre-distraction levels. Compared with patients distracted <30 mm, maximal distraction had a significantly greater improvement in AHI when controlling for preoperative sleep study variables (P = .047).

Patients with isolated RS who have more severe OSA experienced greater improvements in AHI, oxygen requirement, and oxygen saturation after MDO. Two-thirds of patients no longer had oxygen requirements after MDO. Our results suggest that MDO is helpful in treating patients with RS regardless of distraction distance. However, our study provides evidence that increasing the distraction distance may further improve AHI, which is particularly beneficial to patients with a significant preoperative AHI.