title: Analytical investigation of salivary calculi, by mid-infrared spectroscopy.
abstract: 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.
authors.affiliation: Hospices Civils de Lyon, Hôpital de la Croix-Rousse, Centre de Biologie Nord, F-69317 Lyon, France. sabot@univ-lyon1.fr
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Sabot
authors.forename: Marie-Paule
authors.initials: MP
authors.lastname: Gustin
authors.forename: Katia
authors.initials: K
authors.lastname: Delahougue
authors.forename: Frédéric
authors.initials: F
authors.lastname: Faure
authors.forename: Christelle
authors.initials: C
authors.lastname: Machon
authors.forename: Daniel-Jean
authors.initials: DJ
authors.lastname: Hartmann
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D017886:Durapatite / Q000032:analysis; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009930:Organic Chemicals / Q000032:analysis; D015494:Salivary Gland Calculi / Q000737:chemistry* / Q000473:pathology; D012471:Salivary Proteins and Peptides / Q000032:analysis; D013055:Spectrophotometry, Infrared / Q000379:methods*; D055815:Young Adult
chemical_list: D009930:Organic Chemicals; D012471:Salivary Proteins and Peptides; D017886:Durapatite