To Distract or Not to Distract for Frontorbital Advancement in Craniosynostosis

Background: Fronto-orbital advancement (FOA) is the standard procedure for craniosynostosis. One of the disadvantages of FOA is bony gap behind the advanced segments, especially when FOA is performed in older patients. For midface advancement including Le Fort III and Monobloc advancement, the distraction osteogenesis is more used in routine clinical practice. Recently, posterior calvarial vault expansion using distraction osteogenesis is also performed. However, to the best of our knowledge, FOA by distraction osteogenesis is not rarely performed except for Asian countries. It seems that FOA by distraction osteogenesis is not obtained its consensus and indications. In this study, we evaluated the postoperative bone formation on the gap of the cranium retrospectively, and investigated the usefulness and indications for FOA by distraction osteogenesis.

Method: This study was carried out in patients with nonsyndromic craniosynostosis who underwent a FOA with or without distraction osteogenesis between 2010 and 2015. Normally FOA was not indicate for scaphocephaly, so scaphocephaly was excluded in this study. Under 2 years old, conventional FOA was performed. Over 2 years, FOA by distraction osteogenesis was performed. Computed tomography scans were obtained immediately after the operation and 1 year post-surgery, the reossification area was evaluated from the bone defect of the cranium. The bone defect of the cranium was measured by DICOM manager.

Results: 31 patients were included in this study. The cases under 1 years who performed without distraction obtained approximately complete reossification. However, the reossification in cases operated over 1 years were significantly lower reossification in patients under 1 years (p<0.01). In contrast, in cases operated over 2 years who performed FOA by distraction obtained more approximately reossification.

Conclusions: From the results who performed conventional FOA, operative age is one of the factors for influence the reossification. Previous literatures also described that higher age of the patient at surgery is associated with incomplete reossification. However, despite the operative age is older, in patients who performed FOA by distraction had more complete reossification. These results supported that FOA by distraction osteogenesis is recommended in elder patients. Of course, for younger patients under 1 years old, the conventional FOA is much suitable to consider about the disadvantages of distraction osteogenesis such as removing distractors and long-term hospitalization. One of the reason that the FOA by distraction osteogenesis is commonly performed in our country is the delay of medical reference from pediatrician. This is suggested that enlightenment for pediatricians is necessary to perform the conventional FOA in early age.