External versus Internal Distraction Devices in Treatment of Obstructive Sleep Apnea in Craniofacial Anomalies

BACKGROUND: Obstructive sleep apnea is often associated with congenital craniofacial malformations due to hypoplastic mandible and decreased pharyngeal airway. In this study, we will compare external and internal distraction devices for mandibular lengthening in terms of effectiveness, results, patient comfort, and complications. METHODS: Thirty-seven patients were treated by bilateral mandibular distraction osteogenesis for obstructive sleep apnea: 20 with external and 17 with internal distraction devices. RESULTS: Lengthening of the mandible and increase of the pharyngeal airway were obtained in all patients. Using the external devices, the average mandibular elongation was 30 mm versus 22 mm with the internal devices; however, after 1 year, the results were more stable with internal devices. External devices carried greater risk for pin tract infection than the internal devices (27.5% vs 5.88%). In addition, pin loosening in 22.5% required pin replacement or led to reduced retention period. Internal devices had a precise and predictable vector of lengthening and left less visible scars at the submandibular area but carried the disadvantage of requiring a second operation for device removal. In very young children with severe micrognathia, it was impossible to place internal devices, and external devices were used. CONCLUSIONS: Internal devices should be the first choice because they are more comfortable to the patients, more predictable vector of lengthening, are less vulnerable to dislodgement, and leave reduced scarring, with the great disadvantage of second operation for removal. However, external devices still should be considered mainly in severely hypoplastic cases, and the surgeon should be prepared for both options.