Oral mucosal wetness in hypo- and normosalivators

Area of Science:

• Oral biology
• Salivary diagnostics
• Dental research

Background:

• Residual saliva forms a film on oral tissues after swallowing.
• Oral mucosal wetness varies across different sites, with lips and palate being least moist.
• Hyposalivation (low saliva flow) is linked to dry mouth symptoms.

Purpose of the Study:

• To measure residual saliva film thickness on oral mucosal surfaces.
• To correlate saliva thickness with saliva flow rates in healthy and dry-mouth individuals.
• To investigate the relationship between hyposalivation, mucosal wetness, and oral pH.

Main Methods:

• Measured residual saliva thickness using Sialopaper strips and a Periotron 6000 micro-moisture meter at 22 oral sites.
• Recruited three groups: 25 normal individuals and 50 individuals with dry mouth (two subgroups based on flow rates <0.1 ml/min and >0.1 ml/min).
• Calculated saliva thickness by dividing collected saliva volume by the Sialopaper strip area.

Main Results:

• Individuals with dry mouth (flow rates 0.04 and 0.19 ml/min) had mean saliva thicknesses of 22.4 and 27.8 microns, respectively.
• Normal individuals (flow rate 0.39 ml/min) had a mean saliva thickness of 41.8 microns.
• Lower saliva flow rates correlated with reduced mucosal saliva thickness; symptoms became apparent below 0.1-0.2 ml/min. A consistent pattern of oral wetness was observed across all groups.

Conclusions:

• Reduced saliva flow rates lead to thinner residual saliva films on oral mucosa.
• Hyposalivation below a critical threshold (0.1-0.2 ml/min) compromises mucosal hydration, contributing to dry mouth.
• Lower saliva flow and mucosal wetness are associated with increased salivary acidity, potentially impacting dental plaque pH.