Background : Distraction osteogenesis (DO) as a treatment for pediatric craniomaxillofacial deformities enhances the patient’s typical restricted facial growth potential. Virtually planned tridimensional models are useful to design osteotomy’s location, vector’s direction and to chose the appropriate distraction device.

Methods : Retrospective analysis of 10 cases (mean 12.7 years) treated at our service between 2011 and 2012, that underwent mandibular distraction using esterolithographic models. Preoperatively, the information obtained from high definition CT scans in DICOM format was transferred for virtual simulation with MATERIALISE and esterolithographic models were built. Internal approach was performed in 60% of the cases, external and combined were performed in 20%, respectively. External multivectorial devices were placed in 2 patients and internal in 8. The distraction rate was 0.66–1 mm/day. Certain degree of overcorrection was pursued. The consolidation period was 3.75 months. Postoperatively, cephalometric analysis was performed to assess the elongation obtained and clinical evaluation reported the occlusion type and facial symmetry improvement. The final results were compared with predicted ones by measuring their concordance.

Results : The mandible elongation mean was 22.8 mm (unilateral cases 26.4 mm and in bilateral cases at least one side was distracted 20 mm), the distraction was considered satisfactory in 90% of the cases; the rate of major complications was 10%. The vector’s direction was considered adecuate in 100% of the cases.

Conclusions : Surgeon’s experience, intrinsic growth restriction of these patients, effect of muscle forces, fulfillment of orthodontic treatment and technical limitations of the devices are the main factors that might influence the discrepancies between the planification and the final results. These outcomes improve those obtained traditionally however they still do not assure the treatment success.

Key words : virtual planification; distraction osteogenesis; congenital deformities