The purpose of this study was to measure changes in the airway cross-sectional area of pediatric patients with
micrognathia and obstructive airway symptoms
after treatment by mandibular distraction. The measurements obtained were correlated with the clinical outcomes.Ten patients, ranging in age from 3 months to 8 years, underwent measurement and distraction. Eight patients were under 30 months of age. Six were diagnosed with
Pierre Robin sequence, two with
Treacher Collins syndrome, and two with
Nager syndrome. All patients had
retrognathia of greater than 8 mm and obstructive airway symptoms while awake that had resulted in
tracheostomy (3), repeated
apnea monitor triggering (5), or abnormal sleep study (2). Cephalometric analysis was performed pretreatment and posttreatment by distraction. The effective airway space was defined with the following boundaries: a horizontal line from the tip of the odontoid to the velum, the uvula tip to the tongue base along the shortest line, the tongue base down to the base of the epiglottis, and the horizontal line to the posterior pharynx. These lines were traced for each cephalogram, the outline was digitized, and the area was calculated by computer. An analysis of the square area change was done by paired t test. The range of distraction was 8 to 22 mm; the mean effective airway increase was 67.5 percent, with a range of 26 to 120 percent. Measurable airway increase occurred in all patients who underwent distraction, and all patients showed clinical improvement. Six patients with
Pierre Robin sequence became asymptomatic, with normal sleep, feeding, and
weight gain. Two patients with
Nager syndrome and
tracheostomies were decannulated and were asymptomatic postdistraction. One patient with
Treacher Collins syndrome without
tracheostomy became asymptomatic after mandibular distraction; one patient failed to distract because of premature consolidation and continued to require a
cannula. Mandibular distraction seems to provide a consistent change in tongue base position that improves obstructive airway symptoms by increasing measured effective airway space. The potential for mandibular distraction exceeds the simple correction of
malocclusion also by eliminating soft-tissue obstruction of the micrognathic airway. Airway improvement is independent of the syndrome diagnosed. Mandibular
distraction osteogenesis may be useful to avoid or decannulate existing
tracheostomy in infants with
micrognathia.