The relationship between oral health and overall systemic wellbeing is well recognised, particularly when it comes to conditions such as cardiovascular disease and diabetes. But new research is shedding light on another important area: brain health.
A recent study published in the Journal of Periodontology has explored how periodontitis may affect brain function—even in patients with no visible signs of cognitive impairment. The findings raise the possibility that dental professionals may have a meaningful role to play in the early identification and prevention of conditions such as Alzheimer’s disease.
Why the Link Matters
While earlier studies have found that periodontal pathogens can reach the brain and aggravate existing Alzheimer’s pathology, little was known about how these changes might affect patients who are still cognitively healthy. This study is the first to examine how brain function is altered in middle-aged and elderly individuals with varying levels of periodontal disease, but no cognitive symptoms.
The goal was to determine whether periodontitis might trigger subtle neurological changes long before memory loss begins—potentially opening the door to earlier intervention and prevention.
Study Overview
The study included 51 participants over the age of 50, all with normal cognitive function. They were divided into three groups based on periodontal status:
- Healthy (n=11)
- Mild periodontitis (n=14)
- Moderate to severe periodontitis (n=26)
Each participant underwent a full periodontal examination, including probing depth, clinical attachment loss, and bleeding on probing. To assess brain function, researchers used resting-state functional MRI (fMRI) scans, which measure communication between different areas of the brain.
Advanced image analysis techniques were then used to examine how these brain networks were behaving—both within specific systems (such as memory and attention) and between different networks.
Key Findings
The results showed that even in people with no symptoms of cognitive decline, periodontitis was associated with significant changes in brain function.
Participants with moderate to severe periodontitis showed:
- Weakened communication in memory and attention networks
- Strengthened connections within sensorimotor networks—likely a sign of the brain attempting to compensate
- Abnormal communication between auditory and attention-related brain regions
These disruptions were closely linked with clinical periodontal measurements, particularly probing depth and attachment loss. Interestingly, no such differences were observed in participants with only mild periodontitis—suggesting a threshold effect where neural function becomes compromised as disease severity increases.
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What This Could Mean for Dentists
The most important takeaway is that brain connectivity may begin to change in the early stages of neurodegenerative disease—well before any clinical signs appear. If periodontal disease plays a role in triggering or accelerating this decline, then dentists could find themselves in a powerful position to support early intervention.
Periodontal care may not only protect oral health but could also help preserve long-term cognitive function. While this study doesn’t establish a direct cause-and-effect relationship, it adds weight to the idea that managing chronic inflammation in the mouth may benefit the brain as well.
Study Limitations
As with any early research, caution is needed. The study involved a relatively small number of participants and did not measure key Alzheimer’s biomarkers such as amyloid-beta or tau proteins. Larger, longitudinal studies will be necessary to confirm and build upon these findings.
About Dr. Jamal
Dr. Jamal Giri is an orthodontist and associate professor at B.P. Koirala Institute of Health Sciences in Nepal. He obtained his orthodontic training from the Institute of Medicine, Tribhuvan University, Nepal, in 2014.
Currently pursuing a PhD at the University of Adelaide, Dr. Jamal’s research focuses on the genetic and environmental factors influencing malocclusion development. He also holds a postgraduate certificate in clinical education from the University of Edinburgh and a master’s in medical education from the University of Nottingham.Dr. Jamal teaches on the Diploma in Orthodontics and Dentofacial Orthopaedics at the London Dental Institute.
Reference
Ye W, Tao Y, Wang W, Yu Y, Li X. Periodontitis associated with brain function impairment in middle‐aged and elderly individuals with normal cognition. Journal of Periodontology. 2024. Read the full article here
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