“…Previous studies on pneumonia in the elderly population reported that the risk factors included comorbidity (heart disorder, cerebrovascular disease, lung disease, diabetes mellitus, and malignant tumours) [ 34 ], gender (male) [ 9 , 35 , 37 ], smoking habits [ 9 , 35 , 37 ], nasogastric tube feeding [ 36 , 38 , 39 ], swallowing difficulty [ 36 , 38 , 39 ], use of sedatives [ 36 , 38 , 39 ], and analgesics [ 36 , 38 , 39 ]. In addition, it was reported that oral health care reduced the incidence of pneumonia [ 11 , 12 , 13 , 14 ]. We also observed that gender (male) and cerebrovascular diseases were risk factors for pneumonia onset in the subjects in the present study.…”