Purpose: Unicoronal synostosis (UCS) remains one of the most difficult craniofacial conditions to treat. This review attempts to consolidate all existing literature from the past 25 years that has investigated surgical treatment of nonsyndromic UCS. Additional attention is paid to specific areas of controversy regarding surgical management and evaluation of UCS: outcomes of fronto-orbital advancement (FOA) versus endoscopic strip craniectomy (ESC), emergence of spring-associated cranioplasty for craniosynostosis, and morphologic assessment metrics.
Methods: A literature search from 1992 to 2017 was performed with a defined search strategy and manual screening process. About 24 studies were included in the final review.
Results: There is inconsistency among studies in measuring outcomes. Despite wide utilization, FOA produces mixed results, especially when looking at long-term outcomes. Preliminary data suggest advantages to using ESC over FOA with regard to facial symmetry, postoperative strabismus, and operating time. Distraction osteogenesis has long been utilized in Asia and is now being actively studied in the United States. Data on spring-assisted cranioplasty are lacking. Long-term results at skeletal maturity for many of these techniques are lacking.
Discussion: Despite some promising results, methods of measurement are inconsistent and long-term data are lacking. All future research in this area would benefit from consistent and standardized reporting of data, including perioperative statistics and reproducible 3-dimensional computed tomography craniofacial measurements. Additionally, no definitive recommendations can be made until data at skeletal maturity are studied, and all studies would benefit from long-term follow-up data.