Improvement in food comminution at swallowing threshold with newly fabricated removable dentures

Comminution of food into small particles through mastication is important for safe swallowing. However, few studies have evaluated the functional improvement provided by newly fabricated removable dentures in terms of changes in the comminution of food at the swallowing threshold (CF-ST). This prospective cohort study aimed to clarify the changes in CF-ST associated with the fabrication of newly removable dentures.

Eighty patients (age: 57.3 ± 11.9 years) requiring new removable dentures were enrolled. Masticatory performance (MP) and CF-ST were assessed before and after new denture insertion. MP and CF-ST were defined as the increase in surface area of 5.5 g of test gummy jelly after 30 chewing cycles and after chewing until the premeasured swallowing threshold, respectively. Other oral functions, including tongue pressure, oral diadochokinesis, and stimulated salivary flow rate, were measured concurrently. All evaluation items were compared before and after new denture insertion. Multiple regression analysis was performed to identify factors affecting changes in CF-ST.

CF-ST, MP, and other oral functions significantly improved after new denture insertion. Multiple regression analysis identified changes in MP (β = 0.467), number of chewing cycles at the swallowing threshold (β = 0.322), and belonging to Eichner index C group (β = 0.245) as significant factors influencing changes in CF-ST.

Newly fabricated removable dentures have the potential to improve CF-ST. This improvement may result from enhanced masticatory function and changes in masticatory behavior, such as increased chewing.