Metopic synostosis is a craniofacial condition characterised by the premature fusion of the metopic suture. This early fusion restricts frontal bone growth  and has significant impacts on the developing infant during a critical phase of rapid growth and development . Diagnosis of the condition is usually achieved by clinical assessment, followed by a three-dimensional computed tomography (3D CT) scan, verifying premature metopic suture fusion.
Purpose: This retrospective study aims to investigate the timing of metopic suture fusion in the developing infant in an Australian subpopulation.
Methods: The study evaluates metopic suture fusion in 258 cranial 3D CT scans of children aged 0–24 months over a 5-year period (2011–2016), scanned at Women’s and Children’s Hospital.
Results: The findings suggest that the age range over which physiologic metopic suture fusion occurs is larger than previously reported.
Conclusions: The approximate range for physiologic fusion was found to be 3–19 months and patients with fusion within this range can be considered normal. Complete suture fusion is expected by 19 months. Additionally, results indicate suture fusion prior to 3 months is abnormal and diagnostically indicative of metopic synostosis.