An anatomical study of wormian bones from the eastern part of India: is genetic influence a primary determinant of their morphogenesis?

Wormian Bones: Prevalence, Topography, and Implications

BACKGROUND

Wormian bones also known as sutural bones are asymmetrical and shapeless bones occurring in cranial sutures and fontanelle of the skull. Their incidence is reported to vary in population. The exact etiology is debatable, but their formation is under the control of both genetic and environmental factors and has great anthropological and clinical implications related to the cranium. Due to high clinical relevance of Wormian bones, the study was carried out. The aim of the study is to expound the incidence and topography of Wormian bones along with clinical significance in dry adult skulls of Indian origin.

METHODS

The study was conducted in the Department of Anatomy using 200 complete adult dry skulls of unknown age and sex. All the sutures in the skull were inspected for the presence of Wormian bones. The Wormian bones were classified into 10 categories, and associated implications were brought out. The Wormian bones were photographed, and details were compared with the available literature.

RESULTS

The Wormian bones were observed in 190 (380 sides) skulls with 186 on the right side and 108 on the left side. The predominance site of sutural bone was lambdoid suture followed by sagittal suture. The least common site of Wormian bone was lambda.

CONCLUSION

The detailed information of precise topography, frequency, and number of Wormian bones is of utmost use for surgeons performing surgery on the skull, anthropologists for identifying races, and forensic scientists for investigating child abuse cases.

Wormian bone types: investigating their appearance, correlation to sex, population affinity, and clinical syndromes

Background

The types of Wormian bones may play a role in population affinity and differential diagnosis of several clinical syndromes. This study investigates the distribution of types in adult skulls, their correlation to sex, population affinity, and several impairments based on the literature. One hundred ten adult Turkish skulls, 80 (72.7%) males and 30 (27.2%) females, were investigated according to type, frequency, location, and sex. Horizontal and vertical diameters and distances from the mastoid process (MP) were measured with a digital caliper. SPSS 25 was used for all statistical analyses.

Results

A total of 58 (52.72%) Wormian bones were identified from 110 skulls, 38 (65.5%) males and 20 (34.5%) females. The types of Wormian bones revealed significant differences between being on the right, left, or center (p = 0.012). The most frequent type was type 6 (n = 14, 24.1%) in males and type 7 (n = 8, 13.8%) in females. The most frequent type was type 7 in the lambdoid suture and type 8 in the parietomastoid suture.

Conclusions

The present study revealed significant differences regarding the asymmetric distribution of Wormian bones and unilateral asymmetrical types in Turkish skulls. Several factors could contribute to this, including underlying clinical syndrome, deficiencies in embryological development, and population affinity.

Wormian bone types: investigating their appearance, correlation to sex, population affinity, and clinical syndromes

Background

The types of Wormian bones may play a role in population affinity and differential diagnosis of several clinical syndromes. This study investigates the distribution of types in adult skulls, their correlation to sex, population affinity, and several impairments based on the literature. One hundred ten adult Turkish skulls, 80 (72.7%) males and 30 (27.2%) females, were investigated according to type, frequency, location, and sex. Horizontal and vertical diameters and distances from the mastoid process (MP) were measured with a digital caliper. SPSS 25 was used for all statistical analyses.

Results

A total of 58 (52.72%) Wormian bones were identified from 110 skulls, 38 (65.5%) males and 20 (34.5%) females. The types of Wormian bones revealed significant differences between being on the right, left, or center (p = 0.012). The most frequent type was type 6 (n = 14, 24.1%) in males and type 7 (n = 8, 13.8%) in females. The most frequent type was type 7 in the lambdoid suture and type 8 in the parietomastoid suture.

Conclusions

The present study revealed significant differences regarding the asymmetric distribution of Wormian bones and unilateral asymmetrical types in Turkish skulls. Several factors could contribute to this, including underlying clinical syndrome, deficiencies in embryological development, and population affinity.

Prevalence of wormian bones worldwide: a critical review

Wormian bones (WB) are the irregular bone structures developed from additional centers of ossification. Although they are commonly found in healthy individuals, under certain conditions (number >10, mosaic pattern, large size), they can indicate pathology. While their coexistence with numerous diseases is well-documented, and various studies have reported their prevalence in populations of various geographic regions, no qualitative critical review of such studies has been conducted. The aim of this paper is to perform a critical review of research studies on the presence of Wormian bones in populations worldwide, with a particular emphasis on the methodology used and the selection of the samples studied. A sample of 44 original research articles was selected via PubMed and Google Scholar databases. Four criteria were assessed: 1) number of individuals in each group, 2) known sex of individuals, 3) selection criteria of individuals, and 4) implementation of the statistical analysis. The origin of the research sample was determined as well as the method of the WB calculation, and data on the WB prevalence worldwide was collected in tabular form. The reported size of the research samples varies from 22 to 628 individuals, derived from both contemporary and archaeological populations. Four major formulas were used in order to provide the frequency of WB. The sex of individuals was known in 18 (40.9%) articles. Most of the articles focused on Asian samples. The difficulties in comparing data on the Wormian bones are caused by considerable inconsistency in the methodology used to research this phenomenon. Therefore, the interpopulation comparisons currently made may not be correctly estimated. Our study highlights the need for using more comprehensive and consistent data collection as well as processing protocol suitable for populational research on sutural bones.

Nonmetric Variants of Anatolian Crania: A Preliminary Study

Analysis of nonmetric cranial variants has been essential for identifying the human population through osteologic analysis and genetic affinities. This study aimed to examine the nonmetric cranial variants to evaluate differences among sex and side correlations in Anatolian dry skulls. This study was carried out on 50 Anatolian adult dry human skulls (22 males, 28 females) with suitable features (nonfractured and/or with necessary features) out of a total of 97 dry skulls. After sex analysis, each skull was photographed from the norma frontalis, lateralis, inferior, and superior. Eleven nonmetrical cranial variants were investigated. The cranial variants and side incidences were analyzed to determine their sex differences and interside correlations. After the classification, traits were marked as "present" or "absent" on the charts. Some variants in female crania were seen more frequently than in males. Most of the variants such as the supraorbital notch, infraorbital and zygomaticofacial foramen, showed high correlations between the right and left sides. Overall, there were no statistically significant sex or side differences found in the Anatolian crania.

Incidence and Medicolegal Significance of Wormian Bones in Human Skulls in North India Region

Introduction:

Wormian bones (Wbs) are small bones located in or near the sutures of the skull which are irregular in size, shape, and number. The present study is to look into the morphological details of such supernumerary bones of skull with regards to their incidence, number, and topography in skulls from the Haryana region.

Materials and Methods:

This observational study was carried out in the tertiary care hospital, in the region of Haryana and the total of 147 human skulls were examined during routine autopsy procedures with respect to sutures and topographic distribution of Wbs. The data were statistically analyzed.

Results:

In the present study, the overall incidence of Wbs was seen in 52 skulls (35.3%) with males having 23.8% and females having 11.5%.

Conclusion:

The knowledge of incidence and distribution of Wbs in the skull could be useful to radiologists, causality medical officers, and autopsy surgeons in successfully differentiating a skull fracture from normal suture with Wbs or exit gunshot wound from fractured small Wb and thus ruling out the possibilities of presence or absence of fractures due to physical abuse, brittle bones, and exit gunshot wounds. It is also helpful to neurosurgeons in timely diagnosis and management of diseases or fractures in relation to the Wbs.

Adaptive self-organization in the embryo: its importance to adult anatomy and to tissue engineering

The anatomy of healthy humans shows much minor variation, and twin‐studies reveal at least some of this variation cannot be explained genetically. A plausible explanation is that fine‐scale anatomy is not specified directly in a genetic programme, but emerges from self‐organizing behaviours of cells that, for example, place a new capillary where it happens to be needed to prevent local hypoxia. Self‐organizing behaviour can be identified by manipulating growing tissues (e.g. putting them under a spatial constraint) and observing an adaptive change that conserves the character of the normal tissue while altering its precise anatomy. Self‐organization can be practically useful in tissue engineering but it is limited; generally, it is good for producing realistic small‐scale anatomy but large‐scale features will be missing. This is because self‐organizing organoids miss critical symmetry‐breaking influences present in the embryo: simulating these artificially, for example, with local signal sources, makes anatomy realistic even at large scales. A growing understanding of the mechanisms of self‐organization is now allowing synthetic biologists to take their first tentative steps towards constructing artificial multicellular systems that spontaneously organize themselves into patterns, which may soon be extended into three‐dimensional shapes.