Oral Dryness Examinations : Use of an Oral Moisture Checking Device and a Modified Cotton Method

Purpose: This study compared oral dryness measured using an oral moisture checking device and the modified cotton method. Methods: Oral moisture was measured at the lingual mucosa (LM) and the buccal mucosa (BM) using an oral moisture checking device in 13 healthy adults (HA) and 13 patients with oral dryness (OD). The modified cotton method was performed in the same subjects by placing cottons under and over the tongue for 30 seconds and measuring the weight of the saliva absorbed by the cotton. Differences between groups were examined using the Mann-Whitney U-test. Results: The moisture percentage at the LM in the HA and OD groups was 30.0 ± 0.5 % and 28.6 ± 1.1 %, respectively, while the percentage at the BM was 30.3 ± 0.2 % and 29.6 ± 0.7 %, respectively. The amount of hypoglossal salivary secretion in the HA and OD groups was 0.339 ± 0.172 g and 0.036 ± 0.033 g, respectively, while the amount of salivary secretion on the tongue’ s surface was 0.059 ± 0.023 g and 0.011 ± 0.007 g, respectively. Both oral moisture and the amount of saliva at rest were significantly different between the HA and OD groups (P<0.05). Conclusion: Both the oral moisture checking device and the modified cotton method were useful for measuring oral dryness. An oral moisture level of 30 % or less, less than 0.1 g of saliva collected at the hypoglossus within 30 seconds, or less than 0.02 g of saliva collected from the surface of the tongue within 30 seconds may indicate oral dryness.