Effects of the shortened dental arch on oral function in older adults: A prospective cohort study

Abstract

Statement of the problem: Previous longitudinal studies have found that patients with shortened dental arches (SDA) have a higher risk of long-term tooth loss than complete dental arch (CDA). However, the difference between SDA and CDA concerning oral function has yet to be demonstrated. Purpose: We aimed to clarify the influence of molar occlusal support on oral function in SDA and CDA participants cross-sectionally and longitudinally. Materials and methods: We enrolled independent older adults (≥65 years) living in rural areas of Japan. Of these, 257 had CDA, and 21 had SDA without removable prostheses. We assessed the oral function (number of functional teeth, masticatory performance using gummy jelly, occlusal force, oral cleanliness, oral dryness, and maximum tongue pressure) during baseline and two years after baseline (follow-up). Comparison of oral function between SDA and CDA and changes over time were examined using repeated measures analysis of variance and post-hoc test. Results: Cross-sectional analysis showed that both masticatory performance and occlusal force were significantly lower in SDA than in CDA. The functional teeth tended to decrease over time more in SDA than in CDA (p < 0.001). No longitudinal differences were found between SDA and CDA regarding other factors. Conclusions: Participants with SDA had fewer teeth over time than CDAs, but no apparent difference was found in the decline of oral function. Clinical implications: It is notable that prosthetic treatment for patients with SDA, whose main options are either implant or crown prosthesis, removable partial dentures, or no treatment, does not result in a loss of function over time. Prosthetic treatment should be conducted after careful consultation with the SDA patients to determine specific goals for each.

Keywords

• Prosthetic restoration
• Shortened dental arch
• Occlusion
• Tooth loss
• Oral function