Research Notes: Oral (Dental, Salivary, etc.) Aspects of Prader-Willi Syndrome

Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2001 Jul.
Syndromes with salivary dysfunction predispose to tooth wear: Case reports of congenital dysfunction of major salivary glands, Prader-Willi, congenital rubella, and Sjogren's syndromes.
Young W, Khan F, Brandt R, Savage N, Razek AA, Huang Q.
Department of Dentistry, University of Queensland, Australia.

Four cases of congenital dysfunction of the major salivary glands as well as of Prader-Willi, congenital rubella, and Sjogren's syndromes were identified in a series of 500 patients referred for excessive tooth wear. Although there was evidence of consumption of highly acidic drinks, some occlusal parafunction, and unacceptable toothbrushing habits, salivary dysfunction was the salient factor predisposing a patient to tooth wear in these syndromal cases. The 500 subjects have been characterized either as having medical conditions and medications that predispose them to xerostomia or lifestyles in which workplace- and sports-related dehydration lead to reduced salivary flow. Normal salivation, by buffering capacity, clearance by swallowing, pellicle formation, and capacity for remineralization of demineralized enamel, protects the teeth from extrinsic and intrinsic acids that initiate dental erosion. Thus, the syndromes, unrelated in many respects, underline the importance of normal salivation in the protection of teeth against tooth wear by erosion, attrition, and abrasion.

Ann N Y Acad Sci. 1998 Apr 15.
Salivary abnormalities in Prader-Willi syndrome.
Hart PS.
Department of Pediatrics/Section on Medical Genetics, Bowman Gray School of Medicine, Winston-Salem, North Carolina.

Prader-Willi syndrome (PWS) is characterized by psychomotor and growth retardation, infantile hypotonia, characteristic facies, small hands and feet, dental abnormalities, and early onset of childhood hyperphagia with consequent obesity. PWS is associated with abnormalities of chromosome 15. Approximately 75% of patients have a deletion of 15q11q13 on the paternal homologue, whereas 20-25% have inherited both chromosome 15s from the mother and none from the father, a condition known as maternal uniparental disomy (UPD). Thus, it is a lack of paternal alleles in the 15q11q13 region that results in PWS. Thick, sticky saliva is a consistent finding in patients with PWS. We have characterized salivary flow and composition in individuals with PWS. Salivary flow in patients with PWS is approximately 20% of that in controls. In addition, the salivary ions and proteins are present in increased amounts, possibly reflecting a concentration effect relative to decreased water in the saliva. Both deletion and uniparental disomy patients exhibit these findings, suggesting that the gene(s) involved are subject to imprinting.