This study is to investigate whether the improvement or maintenance of cognitive function is superior to the control group when gum chewing is performed in elderly people with subjective cognitive decline or mild cognitive impairment.

The intervention group chew one unscented gum provided by the study for 12 weeks. Using KakaoTalk, the coordinator sends a chewing gum alarm.

The participants are instructed to masticate a gum for 20 minutes every day, alternately for 10 minutes on the right side and 10 minutes on the left side.

After chewing gum, they perform masticatory muscle stretching and tongue exercises. After they finish chewing the gum, he or she reports completion by posting an authentication photo in the KakaoTalk chat room.

The research coordinator checks the certification on a weekly basis and sends a separate phone call to encourage participants who do not chew gum more than twice a week.

Inclusion Criteria:

• 60 to 79 years of age
• All posterior teeth are evenly occluded on both sides, and those who have lost 4 or less teeth in the posterior teeth
• Those who scored 50 points or less on the periodontal disease self-checklist
• Meet the diagnostic criteria for subjective cognitive decline or mild cognitive impairment
• Provide written informed consent

Exclusion Criteria:

• Those who have difficulty in chewing due to toothache, periodontal disease, temporomandibular joint disease, severe malocclusion, shaking teeth, etc.
• Those who wear dentures on the upper or lower teeth
• Dementia
• Major psychiatric illness such as major depressive disorders
• Other neurodegenerative disease (e.g., Parkinson's disease)
• Other serious or unstable medical disease such as acute or severe asthma, active gastric ulcer, severe liver disease, or severe renal disease, or any medical conditions preventing to complete the study as judged by the study physician
• Severe loss of vision, hearing, or communicative disability
• Significant laboratory abnormality that may result in cognitive impairment
• Any conditions preventing cooperation as judged by the study physician
• Coincident participation in any other intervention trial
• Those who are planning dental treatment such as preservation, prosthetics, and implants during the research period

The data that support the findings of this study will be available from the principal investigator upon reasonable request.

Data will be available for 2 years since March 2025.

Reasonable request