Objectives: To evaluate the long-term impacts of oral muscle function training (OMFT) on oral frailty among community-dwelling older adults over a five-year follow-up period. Methods: A 78-year-old woman with chronic conditions, xerostomia, and low tongue pressure capability underwent a home-based OMFT program comprising tongue-pressure strengthening, oral motor exercises, salivary gland and gingival massage, and personalized oral hygiene instruction with motivational interviews. Tongue pressure, oral malodor (ROV), and oral mucosal moisture were measured, and the General Self-Efficacy for Oral Health (GSEOH), Swallowing Monitoring and Assessment Protocol (SMAP), and Geriatric Oral Health Assessment Index (GOHAI) were assessed at baseline in 2020, after eight weeks, and during follow-up in 2023 and 2024. Results: Tongue pressure increased from 20.4 kPa to 28.7 kPa after 8 weeks and remained at approximately 30 kPa until 2024. Oral malodor decreased from 15 to four ROV and remained stable. Oral mucosal moisture improved from 26.6 to > 30 points. Self-efficacy in maintaining oral health increased markedly and new baseline remained high, with the greatest improvement in swallowing-related quality of life occurring in 2023. Oral self-care behaviors improved over time. Conclusions: OMFT may improve oral frailty–related indicators and support longterm oral self-care among community-dwelling older adults.