Ultrastructural analysis of submandibular salivary calculus in combination with X-ray microanalysis

Abstract

Introduction: Sialolithiasis is one of the common diseases of the salivary glands. It was speculated that, in the process of calculi formation, degenerative substances are emitted by saliva and calcification occurs around these substances, and finally calculi are formed. However, the exact mechanism of the formation of calculi is still a matter of debate. The aim of this study: To analyze seven stones ultrastructurally to determine their development mechanism in the submandibular salivary glands. Matherials and methods: To study the morphology (the central and peripheral parts of the submandibular sialolithiasis - n=7) we used a VEGA TESCAN TS 5130MM scanning electron microscope equipped with an Oxford Instruments energy-dispersive x-ray (EDS) system. Results: The study revealed the presence of numerous microstructures of different shapes (nodular, laminar, reticular, microgranular, and multinodular) and variable size arranged in a haphazard fashion. X-ray microanalysis disclosed the component elements in the calculi to be C, Ca, P, Mg, S, Na. The main constituents were Ca and P - in central vs. peripheral parts: 2.5 ± 0.9 vs. 0.8 ± 0.2 (p=0.028) and 2.2 ± 0.7 vs. 0.63 ±0.15 (p=0.02). The major crystals were whitlockite and brushite in central parts of submandibular salivary stone and hydroxyapatite in the peripheral parts. Conclusions: The diverse microstructures encountered strongly suggest that different mechanisms of mineralization occur during growth and development of the sialoliths. High calcium and phosphorous content in the food may be attributed to one of the reasons for the formation of sialoliths.