Dry Mouth Reflex Technix: A Case Study

The dry mouth reflex was first described by Cannon (1937). When areas of the oral mucosa become dry, mucosal receptors trigger the dry mouth reflex, which results in stimulation of saliva secretion. Dehydration of oral mucosa may also trigger thirst through stimulation of tactile receptors (Hirsch, 2015; John E. Hall & Guyton, 2006). Patients with xerostomia may wake up at night feeling the urge to drink (Bots, et al., 2004)The conjunctival epithelium consists of a non-keratinized, two to five cell layers thick, cuboidal stratified, squamous epithelium that covers the inside of the eye lids (the tarsus or palpebra), fornix and bulbus (except cornea) (Figure 5) (Harvey, et al., 2013). Similarly to the OME, the conjunctival epithelium contain

The neural mechanisms that trigger dryness sensation in DED patients are poorly understood (Kovacs, et al., 2016). Cold receptors, polymodal and nociceptors, however, are indicated as important contributors for the sensation of unpleasant dryness (Kovacs, et al., 2016) (Belmonte, et al., 2015; Belmonte & Gallar, 2011).Cytokeratins (CK) are intermediate filaments that are part of the epithelial cell cytoskeleton. They interact with hemidesmosomes and desmosomes and are important in cell signaling and cell polarity (Moll, et al., 2008; Shetty & Gokul, 2012). The combination of CK type and distribution within each epithelial cell type shows high tissue specificity. In the conjunctival epithelium, the superficial squamous epithelial cells are usually CK4 positive, while the glandular goblet cells are CK7 positive (Table 1). CKs consist of pairs of type I (acidic) and type 2 (neutral or basic) CK (Rao, et al., 2014). In response to stress (dryness, shear stress) non-keratinized epithelium can react by keratinizing to form a granular layer and stratum corneum to protect the tissue. This change can be seen in the ocular surface in DED patients (Maumenee, 1979) and in the OME (linea alba) (Canaan & Meehan, 2005; Nanci, 2013)A mucin layer covers and protects the wet epithelial surfaces, such as the ocular surface and the lumen of the gastrointestinal tract, the lungs, and the oral cavity (Argueso & Gipson, 2001; Frenkel & Ribbeck, 2015; Linden, et al., 2008). Mucins are large, highly glycosylated glycoproteins that are either secreted or membrane-bound. Mucins sequester water (Chaudhury, et al., 2015) and have high solubility, elasticity, viscosity and adhesiveness (Coles, et al., 2010; Humphrey & Williamson, 2001; Slomiany, et al., 1996). Even though mucins have a protective role, and the mucus layer serves as a first-line defence,