Morphologic and Aerodynamic Changes of Upper Airway in Pediatric Hemifacial Microsomia Patients Undergoing Distraction Osteogenesis

Abstract

Current studies on hemifacial microsomia (HFM) patients undergoing unilateral distraction osteogenesis (DO) mainly confined to description of facial morphology. This study was to investigate the effect of unilateral DO on upper airway in pediatric HFM patients using computational fluid dynamics. The investigators implemented the present retrospective study composed of 20 patients (age 9.5 ± 2.5 years, 11 males, 9 females) with moderate HFM performed unilateral DO on the ramus of mandible. Computational fluid dynamics models of the upper airway were obtained based on the computed tomography data sets which were taken before and 6 months after distraction. Morphologic and aerodynamic parameters were respectively computed and compared at peak inspiration. Paired t-tests were used to compare the differences between the before and after parameters with the significance set at P < 0.05. The authors observed that after DO, oropharynx and nasopharynx were the major expanded regions, average pressure increased in all cross-sections, average velocity decreased significantly except in the superior border of the epiglottis plane, and the airflow resistance significantly reduced in the whole upper airway (P < 0.05). The results indicate that unilateral DO may expand the constricted oropharynx and nasopharynx, obtain a relatively symmetrical airway shape and decrease the airflow resistance which consequently reduce the workload necessary for breathing and facilitate inspiration.

Postoperative Changes in the Upper Airway Following Mandibular Distraction Osteogenesis in Pediatric Hemifacial Microsomia

“…12 In the few studies that analyzed vertical and oblique vectors of distraction for treatment of unilateral HFM, expansions of the upper airway were found on imaging. 15,16 However, these studies have failed to consider the effects of head and neck position on airway morphology, which has been found to be a significant confounder during 3D airway analysis. [19][20][21] This study uses statistical analysis to take head position into consideration, and the results suggest that mandibular distraction in patients with unilateral HFM may have very minimal impact on the morphology of the upper airway.…”

“…[12][13][14] Mandibular distraction osteogenesis has also been used to successfully treat HFM, with studies demonstrating increased pharyngeal airway volumes and CSA. 15,16 Although MDO has been shown to be as efficacious as similar methods of correcting mandibular asymmetries such as bilateral split sagittal osteotomies, studies have pointed to important limitations to its usage. 11 Notably, the degree of mandibular deformity is a significant factor in treatment outcome, with less severely deformed mandibles seeing greater long-term mandibular stability and outcomes, especially if initially overcorrected.…”

A decade of clinical research on clinical characteristics, medical treatments, and surgical treatments for individuals with craniofacial microsomia: What have we learned?

“…(50,52)Retrospective data showed that placement of a tracheostomy is often considered a first choice of treatment for patients with CFM and severe OSA (50). Unilateral mandibular distraction in patients with unilateral CFM expanded the oropharynx and nasopharynx, and led to less airflow resistance in a retrospective study of 20 patients by Wang et al (53). The high prevalence of OSA in CFM and potential adverse events of not recognizing the disease timely, warrants screening for all patients with CFM and consideration of further testing with polysomnography for those at increased risk (50).…”

The Radiographic “Air Sign” in Neonatal Mandibular Distraction Osteogenesis

“…Keyword mandibular distraction, craniofacial, pierre robin sequence, clinical pearl, airway management Mots-clés craniofacial, distraction mandibulaire, perle clinique, prise en charge des voies respiratoires, syndrome de Pierre-Robin Neonatal mandibular distraction osteogenesis (MDO) has been demonstrated to effectively relieve airway compromise in infants with tongue-based obstruction associated with retrognathia (Robin Sequence). 1,2 Less studied are signs or parameters to determine when MDO has sufficiently expanded the airway to relieve the obstruction, as often such patients were…”

“…Neonatal mandibular distraction osteogenesis (MDO) has been demonstrated to effectively relieve airway compromise in infants with tongue-based obstruction associated with retrognathia (Robin Sequence). 1,2 Less studied are signs or parameters to determine when MDO has sufficiently expanded the airway to relieve the obstruction, as often such patients were dependent on adjunctive airway support such as prone positioning, high flow oxygen, nasal airways, continuous positive airway pressure therapy (CPAP), endotracheal intubation or tracheostomy. 3 Complicating matters further, intubation for surgery in patients that were not ventilator dependent pre-operatively, and oropharyngeal edema secondary to the surgery itself (mandibular exposure and osteotomies) can contribute to a more tenuous airway post-operatively.…”