Salivary parameters and periodontal inflammation in obstructive sleep apnoea patients.
Level 4 - case-series / case-control
Cross-sectional observational study
PubMed 36371504 · doi:10.1038/s41598-022-23957-5
What was done
A cross-sectional study evaluated salivary characteristics and periodontal status in 205 patients undergoing diagnostic overnight polysomnography or polygraphy. Participants were categorized by Apnoea Hypopnea Index (AHI) into three groups: no OSA (AHI < 5; n = 17), mild to moderate OSA (AHI 5–29.9; n = 109), and severe OSA (AHI > 30; n = 79). Salivary analyses included flow rate, pH, electrolytes, and cortisol. Periodontal evaluations assessed tooth count, dental plaque, bleeding on probing, probing pocket depth, gingival recession, clinical attachment level (CAL), and periodontal inflamed surface area (PISA) score.
What was found
There were no significant differences in salivary flow rate, salivary pH, salivary electrolyte concentrations, or electrolyte ratios across OSA severity groups. Participants without OSA had higher salivary cortisol concentrations than those with OSA (p < 0.001). Higher dental plaque scores correlated with higher AHI (r = 0.26, p = 0.003). Based on salivary flow rate, participants with hyposalivation had lower salivary pH, higher electrolyte concentrations, an increased Mg/PO4 ratio (p < 0.001), and a reduced Ca/Mg ratio (p < 0.001). The abstract reported a trend toward higher CAL and plaque volumes in severe OSA, but provided no specific numbers or p-values for these comparisons.
Why it matters
The study shows that while obstructive sleep apnea correlates with dental plaque accumulation, OSA severity does not independently alter salivary flow rate or electrolyte concentrations.
Limits
The cross-sectional design precludes causal conclusions. Group sizes were unbalanced, with a very small non-OSA control group (n = 17 vs 109 mild-to-moderate and 79 severe). The abstract reports no numerical values or confidence intervals for flow rates, pH, electrolytes, pocket depth, or PISA scores, and notes that confounding from medications and comorbidities was not controlled in the reported results.
Cited by
- supports Sleeping with an open mouth causes dry mouth that disrupts the oral microbiome, which requires saliva and a neutral pH.