Anterior Fontanelle Wormian Bone/ Fontanellar Bone: A Review of this Rare Anomaly with Case Illustration

Abstract

Wormian bones are a relatively rare skeletal anomaly that present as accessory bone(s) within the sutures of the cranium and even more rarely within the fontanelles. It is believed that they arise from the formation of abnormal cranial ossification centers. Although not extensively reported in the literature, this anomaly is thought to be associated with other anatomical anomalies such as osteogenesis imperfecta, rickets, and other bone dysplasias. When located within the fontanelles, the most likely site of occurrence is the posterior fontanelle. This case report describes a rare incidence of wormian bone within the anterior fontanelle of an infant who had concurrent craniosynostosis. More research and reporting of this anomaly is necessary to verify any correlated syndromes, and determine the underlying etiology.

Complications in craniosynostosis surgery in patients with rickets: illustrative case and systematic review of literature

“…Nine studies reporting on 12 cases were included for data extraction and analysis (Table 1). [6][7][8][9][10][11][12][13][14] Initial compilation showed consistency with other literature discussing rickets-associated CSS, with a notable male preponderance (67%), previously postulated to reflect a more severe phenotype in males with XLHR, and an average age of 22.1 months (at diagnosis), which aligns with other studies reporting that diagnosis and management occur around 2 years of age. 2,5 Primary involvement of the sagittal suture in 7 of 12 cases (58%), followed by coronal involvement 3 of 12 cases (25%) and both coronal and sagittal involvement in 2 of 12 cases (17%) were noted.…”

“…Unique surgical findings in this disease population include the report by Jaszczuk et al 11 of soft bone and obliteration of the subdural space with endocortical scalloping of the inner table and Glass et al 9 observing similarly diminished subarachnoid space with cortical interdigitation into the inner table. 12 …”

Prevalence of wormian bones worldwide: a critical review

“…The Wormian bones have been reported to commonly occur in healthy populations, and their presence typically is not associated with any pathological conditions (Natsis et al 2019;Andrade et al 2018;Johal et al 2017;Walulkar et al 2012); however, their significant number (above 10), size (more than 6 mm x 4 mm), or characteristic mosaic pattern are clinically considered as indicators of several congenital diseases, mostly osteogenesis imperfecta (Cremin et al 1982) exhibited by abnormally numerous Wormian bones (Semler et al 2010). Other diseases are also frequently associated with WB, such as hypophosphatasia, craniosynostosis, hypothyroidism, cleidocranial dysostosis, rickets, pyknodysostosis (osteopetrosis acro-osteolytica), pachydermoperiostosis, congenital hypothyroidism, hydrocephalus, otopalatodigital syndrome, Hajdu-Cheney syndrome, Menkes syndrome (Ratnaningrum 2020;Saylisoy 2020;Basnet et al 2019 Jeanty et al 2000).…”

Wormian Bone in the Anterior Fontanelle of an Otherwise Well Neonate

“…Cases of Wormian bones within the anterior fontanelle requiring medical or surgical intervention have been previously reported [4]. In addition, there have been reports of anterior fontanelle Wormian bones with other associated clinical findings such as exophthalmos or vascular malformations [5-6].…”