Association Between Oral Health and Swallowing Function in the Elderly

Objective: Although the oral environment significantly affects the risk of pneumonia, there have been few studies regarding its relation with swallowing. There is no doubt that there is a significant link between the oral environment and the development of pneumonia; however, there have been few comparative studies of swallowing using video endoscopy (VE) and video fluorography (VF) as indicators to determine the actual availability of oral intake and the choice of food form. This study was performed to examine whether the oral environment or swallowing function contributes more to the development of pneumonia in the elderly.

Methods: The study population consisted of 24 patients (7 men and 17 women; age range: 64-97 years; average age: 86 years) assessed using the Oral Health Assessment Tool (OHAT), VE and VF at Fukuoka Dental College Hospital. The most common disease was pneumonia (17 patients), followed by cerebral infarction (5 patients), pyelonephritis (4 patients), bronchitis (2 patients), Parkinson's disease (2 patients), scleroderma (1 patient), diabetes (1 patient), eosophageal cancer (1 patient) and Parkinson's syndrome> (1 patient). Some patients had multiple diseases. Oral intake was possible in 20 patients (80%), whereas tube feeding and gastric banding were required in 4 patients.

Results: The OHAT score was not correlated with either the VE or VF score. Furthermore, the OHAT score was not significantly different between the multiple- and no/single-pneumonia episode groups. The group with multiple episodes of pneumonia had lower VE and VF scores than those with no or only a single episode of pneumonia.

Conclusion: Oral assessment, VE and VF are necessary to evaluate swallowing in patients with suspected dysphagia. Swallowing function, especially as assessed by VE and VF, is more important than examination of the oral environment for evaluating risk of recurrent aspiration pneumonia in the elderly. In addition, multiple factors contribute to recurrent pneumonia in patients with a good oral environment, including subclinical aspiration, pharyngeal clearance and delayed activation of the gag reflex.