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This is a cranium from the medieval cemetery St. Helen-on-the-Walls, York. We would like to thank the Yorkshire Museum for the access to this specimen.

Cranium and first cervical vertebra

The atlas (first cervical vertebra) is fused to the occipital in a fixed, slightly rotated position to the right side. This fusion occurs through the occipital condyles and bony bridges between the anterior arch of the atlas to the basilar part of the occipital and between the posterior margin of the transverse processes of the occipital to an area adjacent to the posterior edge of the occipital condyles.  A triangular exostosis projects c. 4-5mm into the foramen magnum from the left occipital condyle.  Viewed from the foramen magnum, interruptions are visible in the superior half of the anterior arch and the superior articular surface of the atlas.  Similarly, posterior to the occipital condyles are interruptions in the surface, spicular compact bone formation, and depressions.  This may be the expression of a occipital vertebra (Barnes: 83).

The cranial base and viscerocranium are asymmetric. Significantly, the right orbit is higher in position by 2.1mm and there is a posterolateral rotation of the viscerocranium of 7mm to the right.  The right mastoid process is 2.2mm larger in length and situated 4.6mm further from the centre of the cranial base. The left side of the occipital and posterior parietal is flattened, while the right side is bulbous.  This asymmetry is due to positional torticollis as a result of congenital fusion of the atlas to the occipital.

Co-existing Pathology:

The mandibular fossae have large osteolytic lesions located laterally on the anterior slope.  The anterior slopes also have multiple shallow linear grooves and new compact bone formation.

References Cited:

Barnes E. 1994. Developmental defects of the axial skeleton in paleopathology. Niwot: University of Colorado Press.

Disease Classification:

Developmental-hyperplastic-congenital fusion

Developmental-dysplastic-vertebral shifts

Developmental-dysplastic-torticollis

Miscellaneous-skeletal-temporomandibular joint disease

Miscellaneous-dental-ante-mortem tooth loss

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