Masticatory ability and functional tooth units in Japanese adults

Abstract

The purposes of this study were (i) to examine the relationship between the number of natural teeth and the number of functional tooth units in Japanese adults, (ii) to evaluate how functional tooth units relate to subjective masticatory ability and (iii) to determine the minimum number of natural teeth and functional tooth units needed to maintain adequate self-assessed chewing function. A self-administered questionnaire was given and dental examination was conducted for 2164 residents aged 40 to 75 years. Counts were made on the number of functional tooth units of natural teeth (n-functional tooth units), the sum of natural teeth and artificial teeth on implant-supported and fixed prostheses (nif-functional tooth units) and the sum of natural teeth and artificial teeth on implant-supported, fixed and removable prostheses (total-functional tooth units). The average number of natural teeth, n-functional tooth units and nif-functional tooth units decreased with age, but these were often replaced by functional tooth units from artificial teeth on removable prostheses. Total-functional tooth units in 50-59 year old people were slightly lower compared with those in other age groups. Subjects who reported that they could chew every food item on an average had 23.4 total natural teeth, 12.6 posterior natural teeth, 7.6 n-functional tooth units, 8.6 nif-functional tooth units and 10.4 total-functional tooth units, and subjects without chewing difficulties had fewer functional tooth units from removable prostheses. Maintaining 20 and more natural teeth and at least eight nif-functional tooth units is important in reducing the likelihood of self-assessed chewing difficulties.

Soft denture liners’ effect on the masticatory function in patients wearing complete dentures: A systematic review

“…Objective assessments have been considered more reliable 43,44 although they require sophisticated equipment; they are time consuming and difficult to implement in large samples 45 . Perceived chewing ability, on the other hand, has been considered to provide valuable information especially for large samples, while subjective methods in general are indisputably simple to implement 46 .…”

Occlusal Force in People in Their Sixties Attending College for Elderly

“…It is necessary to carry out oral health promotions and surveys targeting people under the age of 80. Ueno et al 19) conducted a study on the number of present natural teeth and functional tooth units in 2,164 Japanese aged 40 to 75 years by means of a questionnaire and oral examination to determine decrease in total number of present teeth and functional tooth units with age. Total-functional units, which were defined as pairs of opposing natural teeth and artificial teeth in the 50-59-year age group, was slightly lower compared with that in other age groups.…”

Het krachtenspel van kronen en bruggen in het occlusiesysteem, mede in relatie tot het orofaciale systeem

“…Het is jammer dat in dit onderzoek niet is doorgevraagd of het niet goed kunnen kauwen van sommige soorten voedsel ook als een probleem werd ervaren. Wellicht waren de onderzoekers daarmee tot een andere conclusie gekomen dan hun huidige conclusie dat 20 gebitselementen nodig zijn om geen kauwproblemen te ervaren (Ueno et al, 2008). Een populatie van bijna 1.500 Chinese 40-plussers werd volgens een classificatiesysteem ingedeeld naar functie van het occlusiesysteem met en zonder prothetische constructies en ondervraagd over kauwproblemen bij het eten van 8 soorten voedsel.…”