Closure of the anterior and posterior fontanelle in the New Zealand population: A computed tomography study.

Abstract

Significant ethnic variation has been demonstrated in the closure of the anterior fontanelle (AF); however, to date, this has not been investigated in the Māori/Pasifika population. The computed tomography scans of 163 individuals (116 Māori/Pasifika and 47 New Zealand (NZ) European) aged between birth and 4 years were retrospectively analysed to investigate the surface area (SA) and time of closure of the anterior and posterior fontanelles in New Zealand. The Māori/Pasifika group showed clinical AF closure (SA < 114 mm2 ) rates of 25% at 4-6 months, increasing to 47% at 10-12 months and 80% at 13-18 months. The posterior fontanelle was clinically unfused in 17% of the Māori/Pasifika group aged <1 month and in 7% of the 1-3-month-old group. No cases of posterior fontanelle non-fusion were identified in the NZ European population. This study establishes normal values for AF size and closure frequency for the first time in the paediatric Māori/Pasifika population.