The study, published in the Journal of Hepato-Biliary-Pancreatic Sciences, examined 339 patients who underwent surgery for pancreatic ductal adenocarcinoma at Hiroshima University Hospital between 2014 and 2022.

All patients received dental examinations before surgery, during which researchers recorded their number of natural teeth and assessed the contact between their back teeth.

Researchers found a substantial difference in survival between patients with different numbers of natural teeth.

Those with 21 or more natural teeth had a median overall survival of 60.7 months, compared with 39.1 months among patients with 20 or fewer teeth.

The association remained statistically significant even after researchers adjusted for important factors that can influence pancreatic cancer outcomes, including tumour stage, lymph node metastasis, surgical margins, chemotherapy and nutritional status.

The researchers found that chewing function itself was not independently associated with survival. This suggests that tooth count may reflect more than a person's ability to chew.

Kenichiro Uemura, an associate professor at Hiroshima University and corresponding author of the study, said tooth loss may reflect the effects of long-term inflammation, frailty, nutritional condition, lifestyle factors and overall systemic vulnerability accumulated over many years.

The researchers therefore suggest that the number of natural teeth could serve as a simple marker of a person's broader health and resilience.

The researchers stress that the study does not prove that having more teeth directly improves survival.

It was conducted at a single medical centre and involved patients of Japanese ethnicity, meaning the findings need to be validated through larger, multicentre and international studies.

The team also plans to investigate the possible biological links between oral bacteria, chronic inflammation and pancreatic cancer progression.

Researchers hope that oral health assessments could eventually become part of personalized risk assessment and care for pancreatic cancer patients.