Association between individual and neighbourhood socioeconomic factors and masticatory efficiency: a cross-sectional analysis of the Paris Prospective Study 3.

Background: There is a lack of evidence on the impact of socioeconomic factors on masticatory efficiency. The present study investigates the relationship between individual and neighbourhood socioeconomic factors (main exposure) and the number of masticatory units (MUs) used as surrogate of the masticatory efficiency (main outcome).

Methods: In this cross-sectional study nested in the Paris Prospective Study 3, 4270 adults aged 50-75 and recruited from 13 June 2008 to 31 May 2012 underwent a full-mouth examination.

[Endocrine control of serum phosphate: from the discoveries of phosphatonins to novel therapies].

Phosphate is absorbed through the gut, stored in the bone and reabsorbed through the proximal renal tubule. More importantly, PTH and FGF23 have been identified as the main phosphaturic factors that control the expression of the phosphate co-transporters NaPi-IIa et IIc. By allowing the adjustment of the urinary phosphate reabsorption, these two phosphatonins play a major role in bone and tooth mineralization and growth.

Osteopontin and the dento-osseous pathobiology of X-linked hypophosphatemia.

Seven young patients with X-linked hypophosphatemia (XLH, having inactivating PHEX mutations) were discovered to accumulate osteopontin (OPN) at the sites of defective bone mineralization near osteocytes - the so-called hallmark periosteocytic (lacunar) "halos" of XLH. OPN was also localized in the pericanalicular matrix extending beyond the osteocyte lacunae, as well as in the hypomineralized matrix of tooth dentin. OPN, a potent inhibitor of mineralization normally degraded by PHEX, is a member of a family of acidic, phosphorylated, calcium-binding, extracellular matrix proteins known to regulate dental, skeletal, and pathologic mineralization.