A Cross-sectional Study of Wormian Bones in the Cranium: Exploring their Clinical Significance and Diagnostic Implications

Abstract

Introduction: Wormian Bones (WBs) are small, irregularly shaped ossicles often located within the cranial sutures and at the fontanelles, with the majority found in the lambdoid sutures. They result from the formation of abnormal ossification centres in the cranium that develop through an unknown mechanism. Clinically, Significant Wormian bones (SWBs) are defined as bones arranged in a general mosaic-like pattern with a size larger than 6×4 mm; for pathological significance, more than 10 such SWBs should be present. Aim: To study the incidence of WBs in various sutures of human dry skulls and to investigate the incidence of the metopic suture and Inca bone in human dry skulls. Materials and Methods: The present cross-sectional study was conducted in the Department of Anatomy, Government Doon Medical College, Dehradun, Uttarakhand, India, from January 2024 to May 2024. In the present study, 38 dried adult human skulls of unknown age and sex were examined for the presence, number and location of WBs, the metopic suture, and the Inca bone in various sutures of the skull. The data were analysed using descriptive statistics, and results were expressed in terms of incidence. Results: Wormian bones were present in 21 (55.26%) skulls, while 17 (44.74%) had no WBs. One (0.27%) skull had a metopic suture, and 1 (0.27%) skull had an Inca bone. Pathologically significant WBs were not found in any of the skulls examined. Conclusion: The overall incidence of WBs is 55.26%, while the incidences of the metopic suture and Inca bone are both 2.63%. Thus, WBs may mimic a cranial fracture, leading to misdiagnosis, which could delay or alter treatment. Additionally, some WBs may be lost during putrefaction, giving the appearance of an entry/exit gunshot wound in postmortem cases.

Keywords

• accidental bones
• epipteric bones
• intercalated bones
• pterion ossicles
• supernumerary ossicles
• sutural bones