Background and objectives: Obstructive sleep apnea is often associated with congenital craniofacial malformations due to hypoplastic mandible and decreased pharyngeal airway. The patients were treated using external or internal distraction devices for mandibular lengthening.

Methods: 19 patients were treated by mandibular distraction using external distraction devices and 16 patients with internal distraction devices. Comparison between the two methods and the advantages and disadvantages will be presented.

Results: In all the patients an increase in mandibular body and pharyngeal airway was obtained. Using the external devices the average mandibular elongation was 31 mm. They are less comfortable to the child, leave 2 visible skin scares and note pin loosening in 7 sides that need another procedure for pin placement or may lead to shorter retention period with greater relapse. The removal of the external devices is simple. Using internal devices the average mandibular elongation was 22 mm. They are more comfortable to the child with a precise and predictable vector of lengthening and leave less visible scar at the submandibular area. However they need second operation for removal under general anaesthesia. In some cases in very young children with severe micrognathia, it was impossible to place internal devices, and external devices were used.

Conclusions: Internal devices are more comfortable to the child with a precise and predictable vector of lengthening. They leave less visible skin scar and should be consider first with the main disadvantage of second operation for removal under general anaesthesia. The external devices permit greater distraction length, however when it was impossible to place internal devices or when there is a need for greater distraction length, the external devices may be used with the main drawback for child discomfort and risk of pin loosening that need replacement or shortening the retention period.