Identifying sialoliths through SEM technology.

OBJECTIVE

To define SEM characteristics that may aid identification of sialoliths.

MATERIALS: Two sialoliths from modern patients affected by sialadenitis.

METHODS

Samples were coated with silver and subjected to scanning electron microscopy using an energy-dispersive X-ray spectroscopy detector. Samples were then sectioned to permit study of the internal structure.

RESULTS

Sialoliths show an external smooth surface with no distinctive features. Internal structures consist of a distinctive aggregate of coarse granules of different sizes surrounded by a lamellar coat. Elemental composition consists of carbon, phosphate, calcium and oxygen, with traces of magnesium. The proportion of these elements differs between the core and the surface.

CONCLUSION

Although elemental composition is not specific, SEM analyses of sialoliths greatly differ from those of sesamoid bones, gallstones and nephroliths. Therefore, SEM analysis constitutes a useful tool for the precise identification of small calcified structures recovered during archaeological excavations.

SIGNIFICANCE: Precise identification of calcified structures may provide information about nutritional and/or pathological aspects of past individuals.

LIMITATIONS: Sialoliths are less common than other types of calcifications, and only two cases were analyzed in this study.

FUTURE PROSPECTS: SEM technology should be applied to identify the etiology of all minute calcified remains recovered during archaeological excavations of burial sites.