•The combination subgaleal drainage with one burr-hole instead of one burr-hole with subdural drainage is non-inferior.•Subgaleal drainage in cSDH with one burr-hole seemed to be equally efficient and safe compared to two burr-holes.•The use of subgaleal drain leads to a significant lower risk for seizures.

The shift towards alloplastic materials in cranioplasty reflects regulatory pressures rather than material-specific considerations. Despite variability in practice, our findings underscore the need for standardized guidelines and further research to optimize patient outcomes. This study provides valuable insights into current practices and highlights areas for future investigation in cranioplasty.