This spun off many modern words, including "calculate" (use stones for mathematical purposes), and "calculus", which came to be used, in the 18th century, for accidental or incidental mineral buildups in human and animal bodies, like kidney stones and minerals on teeth.Tartar, on the other hand, originates in Greek as well (tartaron), but as the term for the white encrustation inside casks, aka potassium bitartrate commonly known as cream of tartar. This came to be a term used for calcium phosphate on teeth in the early 19th century. Calculus composition
Calculus is composed of both inorganic (mineral) and organic (cellular and extracellular matrix) components. The mineral proportion of calculus ranges from approximately 40–60%, depending on its location in the dentition, and consists primarily of calcium phosphate crystals organized into four principal mineral phases, listed here in order of decreasing ratio of phosphate to calcium:

whitlockite, Ca9(Mg,Fe)(PO4)6(PO3OH)
hydroxyapatite, Ca5(PO4)3OH
octacalcium phosphate, Ca8H2(PO4)6 · 5 H2O
and brushite, CaHPO4 · 2 H2OThe organic component of calculus is approximately 85% cellular and 15% extracellular matrix. Cell density within dental plaque and calculus is very high, consisting of an estimated 200,000,000 cells per milligram. The cells within calculus are primarily bacterial, but also include at least one species of archaea (Methanobrevibacter oralis) and several species of yeast (e.g., Candida albicans). The organic extracellular matrix in calculus consists primarily of proteins and lipids (fatty acids, triglycerides, glycolipids, and phospholipids), as well as extracellular DNA.
Laryngo-onycho-cutaneous syndrome (also known as Shabbir syndrome) is a rare epithelial disorder inherited in an autosomal recessive fashion. It is characterized by abnormalities in the larynx, nails ("onycho-"), and skin ("cutaneous"). The disorder is only found in Punjabi Muslims and only a few cases have been reported.It was characterized by Pakistani dermatologist Syed Ghulam Shabbir (1923–2002) in 1986.It may be associated with LAMA3. See also
Watson syndrome
List of cutaneous conditions

References
External links
Laryngo-onycho-cutaneous syndrome on MedlinePlus