Mandibular cortical morphology on dental panoramic radiographs as a potential radiographic marker of frailty in community-dwelling older adults: a retrospective cross-sectional study

Abstract

Frailty is a multifactorial geriatric syndrome associated with functional decline and adverse health outcomes in older adults. Panoramic radiography is routinely performed in dental practice and enables incidental evaluation of mandibular cortical morphology without additional imaging. Radiomorphometric indices, such as the mandibular cortical index (MCI) and mandibular cortical width (MCW), are established indicators of bone mineral density; however, their association with frailty remains unclear. This study aimed to examine the relationship between mandibular cortical morphology, assessed on panoramic radiographs and frailty in older adults. This retrospective cross-sectional study included patients who underwent panoramic radiography and completed the Kihon Checklist (KCL) at Agano City Hospital between January 2025 and February 2026. Frailty status was categorized as robust, pre-frail, or frail based on KCL scores. Mandibular cortical morphology was evaluated using MCI, and cortical thickness was measured using MCW. Associations between these indices and the KCL score, frailty status, and other clinical variables were analyzed using correlation analyses and multivariable regression models. A total of 201 participants (mean age 74.7 ± 7.6 years) were included. MCI was significantly correlated with both KCL score ( r = -0.332, p < 0.001) and frailty category ( r = -0.336, p < 0.001). In multivariable analyses, MCI remained independently associated with KCL score and frailty status, whereas MCW showed no significant association. Mandibular cortical morphology assessed on panoramic radiographs was associated with frailty in older adults. Mandibular cortical morphology may reflect frailty more strongly than cortical thickness and could support early identification of frailty in older adults.