Size of the Anterior Fontanelle: Three‐Dimensional Measurement of a Key Trait in Human Evolution

Abstract

The anterior fontanelle (AF) is an integral element of the developing human infant craniofacial system. Consideration of the AF is crucial for assessing craniofacial growth, as altered development of this feature may indicate abnormal growth. Moreover, prolonged patency of the AF may represent a derived hominin feature. The AF is regarded as essential for fetal head molding during birth in humans, with deformation of the head during birth often necessary for successful delivery. However, the function of a patent AF among fossil hominins is unclear. Because the AF represents an important structure in both a clinical and evolutionary context, techniques for estimating the size of the AF must be accurate and reproducible. Therefore, we have developed a novel method for assessing surface area of the AF with the goal of creating a more accurate measure of this feature. In this study, we test the accuracy and repeatability of a novel three-dimensional (3D) method for assessing the size of the AF in human infants and compare the results obtained for surface area of the AF using the conventional and 3D methods. Anat Rec, 297:234-239, 2014. V C 2013 Wiley Periodicals, Inc.

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

“…The anterior fontanelle (AF) is the largest and most important of the six fontanelles present in the newborn skull . It is diamond shaped and consists of a non‐mineralised fibrous membrane located between the developing frontal and parietal bones . This fibrous area accommodates the growth of the brain without compression against the skull and confers a degree of deformity to allow passage of the head through the birth canal .…”

“…1 It is diamond shaped and consists of a non-mineralised fibrous membrane located between the developing frontal and parietal bones. 2,3 This fibrous area accommodates the growth of the brain without compression against the skull and confers a degree of deformity to allow passage of the head through the birth canal. 4 The traditional way of assessing the size of the AF was proposed by Popich in 1972 and uses the examiner's index finger.…”

Anterior fontanelle size among term neonates on the first day of life born at University of Gondar Hospital, Northwest Ethiopia

“…Fontanelles are fibrous gaps occurring when more than two cranial bones are juxtaposed or it can be defined as a place where two or more sutures meet (1)(2)(3)(4). The word fontanelle is derived from the Latin word, Fonticulus and the old French word, Fontaine, meaning a little fountain or spring (2)(3)(4)(5). In the newborn skull six fontanelles can be identified, namely anterior, posterior, two mastoid and two sphenoid fontanelles (6)(7)(8).…”

“…AF size has been utilized as evidence of altered intracranial pressure, an index of the rate of development and ossification of the calvarium (5). It is also an indicator to various medical disorders and abnormal skeletal morphogenesis (2,(4)(5)(6)12).…”

“…It gives useful information to follow the developmental status of the child as well as general state of health and can be considered as an index of cranial growth and development during the prenatal and postnatal period. Any developmental alteration in AF growth presumably is an indicator of an abnormal growth (2,3,6,14).…”