Sialolithiasis is common in salivary glands, especially in the submandibular and parotid ducts. X-Ray diffractometry was the principal technique used for their analysis, sometimes associated with scanning electron microscopy.
Hydroxyapatite was the most frequently described constituent, in association with
whitlockite and other
calcium phosphates as
brushite or octocalcium
phosphate. Proteic matter was detected, as
mucoproteins,
albumin,
nucleoproteins or as degenerative bacterial matter. This study presents the identification of constituents by mid-infrared spectrometry of 74
sialoliths. Their successive layers are analyzed from their crust to the nucleus, using absorbance measurements. Spectra are compared with reference mixtures of two or more constituents. Approximately 99% of
sialoliths are constituted of
calcium phosphates, under carbonated forms. More than three-quarters contain
proteins, in which
mucins represent the majority and
albumin is found in 10% of all the specimens. Only 7%
calculi are an association of two constituents, 66% are made of three and 27% have four or more components. For the 74 studied
sialoliths, no specimen contains
hydroxyapatite; but they are composed of
carbonate apatites with irregular microcrystallized forms, even if
proteins are present. Some of them have a pure
protein nucleus, surrounded by
carbonate apatite layers; the other stones are made of internal layers of
apatites and covered with a dense and varnished crust of
proteins.