Three-dimensional printing of surgical guides for mandibular distraction osteogenesis in infancy

Abstract

Pierre Robin sequence (PRS) is a congenital malformation characterized by micrognathia, glossocoma, and mechanical obstruction of the upper respiratory tract. These deformities impair respiration, sleep, feeding, and swallowing, and can lead to malnutrition, stunted development, and death. Bilateral mandibular distraction osteogenesis, whereby the mandible and tongue root are extended outward, is the standard treatment to relieve upper airway obstruction in severe PRS. Accurate placement of the distraction device is essential but challenging, especially in infants, and requires the pre-operative fabrication of surgical guides based on CT images. Three-dimensional (3D) printing allows for the accurate recreation of objects from digitized models. We compared surgical efficacy and safety of bilateral mandibular distraction osteogenesis using 3D printed or traditionally fabricated surgery guides for treatment of infants with severe PRS.During the period from 2014 to 2016, 22 patients with severe PRS were treated using either traditional or 3D printed surgery guides. We compared outcome measures of operations, including intraoperative bleeding, operation time, and postoperative complications.The 3D printed surgery guide group demonstrated significantly shorter operation time (P <.05) as well as moderately shorter hospital stay and artificial ventilation time (∼1 day less). Furthermore, despite markedly younger average age of the 3D printed group (1.3 vs 3.5 months), there was no increase in postoperative complications using the 3D printed guides.Three-dimensional printed surgery guides were used successfully for bilateral mandibular traction osteogenesis, and according to several outcome, parameters demonstrated superior efficacy and safety compared to traditional guides. Further research is warranted to extend the applications of 3D printed surgical guides for craniofacial surgery.

Figure 1

Fabrication of a handmade surgical guide (control group). A) The mandible model is obtained. B) The handmade surgical guide is produced using self-condensing plastics. The osteotomy line and fixation screw positions are recorded. C) The final handmade surgical guide is obtained.

Figure 2

Fabrication of a 3D printed surgical guide. A) Data collection by CT. B) 3D modeling using Mimics software. C) Model import to 3magic software. D) The tractor position is simulated. E) The osteotomy line and fixation screw positions are determined. F) The surgical guide is designed and exported for 3D printing.

Figure 3

3D remodeling using 3magic. A) Left mandible model with surgical guide. B) Left mandible model with surgical guide showing fixation screw positions. C) Right mandible model with surgical guide. D) left mandible model with surgical guide showing fixation screws.

Figure 4

Bilateral mandibular distraction osteogenesis using a 3D printed surgical guide. A) The incision position is marked on the patient's face. B) Morphology of the 3D printed surgical guide before use. C) The surgical guide is placed temporarily inside the incision. D) The fixation screw positions are marked by holes on the surgical guide. E) The fixation screws are placed accordingly. F) The surgical guide is removed at the end of the operation.