Posterior Fontanelle Closure Delayed

The triangular posterior fontanel is located at the junction of the occipital and two parietal bones 1 5.

Posterior fontanelle closure delayed. Delayed closure means persistence of open fontanel beyond 24 months of age. In humans the sequence of fontanelle closure is as follows. The posterior fontanelle generally closes between 6 weeks and 3 months after birth.

Widened sagittal squamous and lambdoid sutures were also observed. Other than the anterior and posterior fontanelles the mastoid fontanelle and the sphenoidal fontanelle are also significant. The posterior fontanelle usually closes by the 8th week of life and the anterior fontanel closes by the 18th month of life on average.

Prominent vascular markings of the bony calvarium are also common as is delayed closure of the anterior and posterior fontanelle which remained patent at a mean age of 7 4 years on a recent retrospective study of craniofacial findings ullrich et al 2012. Most anterior fontanel close between 18 24 months of age. Closure of fontanelles and sutures delayed dentition horse riding stance thin limbs with prominent stiff joints coxa valga skeletal hypoplasia and dysplasia dystrophic ncbi nlm nih gov cranial fontanelles thin short clavicles dwarfism abnormally gracile ribs involving the posterior segments of the upper ribs slender long.

The sphenoidal and posterior fontanelles close during the first few months of life. This term applies if there is delay of closure of the fontanelles beyond the normal age. The posterior fontanelle is on the upper rear part of the baby s head.

A list of the medical conditions associated with a large fontanel or delayed fontanel closure can be found in table 1 20 21 achondroplasia congenital hypothyroidism down syndrome rickets and. This fontanelle is at the intersection of three different bones. 1 posterior fontanelle generally closes 2 3 months after birth 2 sphenoidal fontanelle is the next to close around 6 months after birth 3 mastoid fontanelle closes next from 6 18 months after birth and 4 the anterior fontanelle is generally the last to close between 1 3 years.

It is the first to close. The closures eventually form the sutures of the neurocranium. Large fontanel or delayed fontanel closure are discussed later in this article.