Xerostomia, or chronic dry mouth, is a common syndrome caused by a lack of
saliva that can lead to severe eating difficulties, dental caries and oral candida infections.
The prevalence of xerostomia increases with age and affects approximately 30% of people
aged 65 or older. Given the large numbers of sufferers, and the potential increase in
incidence given our aging population, it is important to understand the complex mechanisms
that drive hyposalivation and the consequences for the dentition and oral mucosa. From this
study we propose the Fgf10 +/- mouse as a model to investigate xerostomia. By following embryonic salivary
gland development, in vivo and in vitro, we show that a reduction in Fgf10 causes a delay in branching of
salivary glands. This leads to hypoplasia of the glands, a phenotype that is not rescued postnatally or by
adulthood in both male and female Fgf10 +/- mice. Histological analysis of the glands showed no obvious
defect in cellular differentiation or acini/ductal arrangements, however there was a significant reduction in their
size and weight. Analysis of saliva secretion showed that hypoplasia of the glands led to a significant reduction
in saliva production in Fgf10 +/- adults, giving rise to a reduced saliva pellicle in the oral cavity of these mice.
Mature mice were shown to drink more and in many cases had severe tooth wear. The Fgf10 +/- mouse is
therefore a useful model to explore the causes and effects of xerostomia.