Functional Tooth Units Research Articles

Association between functional tooth units and chewing ability in older adults: a systematic review

To systematically review the current evidence on the relationship between dentition status and chewing ability in older adults, as the latter was subjectively perceived by questionnaires. Tooth loss is associated with functional impairment regarding chewing ability, depending on the number and the location of the remaining teeth. A search of the English literature was undertaken using the appropriate electronic databases and keywords in order to answer the question of this review. Independent extraction of the related articles was carried out by two authors using predefined eligibility criteria. Full-text analysis was performed for 51 articles of possible relevance. Finally, data were extracted from 18 studies, published in 20 articles that met the inclusion criteria. Although there was a conflict between the studies relevant to the number of functional tooth units needed to maintain adequate oral function, it was revealed that chewing ability was closely related to the number and distribution of teeth remaining. Treatment plan should focus on the preservation of the strategic parts of the dental arch that are critical for adequate oral function. Long-term prospective studies, comprising well-defined criteria, clinical variables, methods and utilising comprehensive questionnaires, should be preferred to obtain a clearer picture on the association between masticatory ability and functional tooth units.

Relationship between oral health literacy and oral health behaviors and clinical status in Japanese adults

Background/purposeHealth literacy is recognized as an important determinant of health as well as a causal factor in health disparities among different population groups. However, the paucity of information on oral health literacy makes urgent the need for more research on this important topic. The objective of this study was to investigate how oral health literacy relates to oral health behaviors, as well as clinical dental and periodontal condition. Materials and methodsA self-administered questionnaire and dental examination collected information on demographics of 589 adult residents of Akita prefecture, Japan, including: oral health behaviors; oral hygiene status; oral health literacy; number of natural teeth, decayed teeth, and functional tooth units (FTUs); and community periodontal index. ResultsLess than half of the participants knew the Japanese words such as “dental plaque,” “scaling,” “gingivitis,” “fluoride mouth rinsing,” “8020 campaign,” “mouthwash,” and “denture plaque,” or answered “true” in response to the statement: “Scaling is related to periodontal disease.” The higher a participant’s oral health literacy, the more often they brushed their teeth or dentures, self-checked oral condition with a mirror, had regular dental checkups, and the better their oral hygiene status. Furthermore, individuals with higher oral health literacy had higher mean numbers of natural teeth, n-FTUs, and nif-FTUs. Participants with higher oral health literacy also had fewer decayed teeth. Participants with low oral health literacy were more likely to fall into a higher category of the community periodontal index code compared to those with high oral health literacy. ConclusionOur findings indicate that oral health literacy is associated with differences in oral health behaviors and clinical oral health status. An understanding of participants’ oral health literacy levels is crucial for designing effective health educational materials and creating intervention programs to promote oral health.

The relationship between seven health practices and oral health status in community‐dwelling elderly Thai

This study aims to analyse the relationship between seven health practices, oral health behaviors, and oral health status in community dwelling elderly Thai. The subjects were 612 elderly people (mean age = 68.8 ± 5.9 years). Questionnaires survey about sociodemographics, self-reported seven health practices and oral health behaviors were conducted by trained interviewers. Oral examinations investigated the number of teeth present, decayed teeth, periodontal status and functional tooth units (FTUs). Oral malodor was assessed by Organoleptic Test, and unstimulated saliva was collected for 5 min. Five health practices (smoking, drinking, physical activity, breakfast and weight maintenance) were significantly related with oral health behaviors. ancova analysis demonstrated the following significant associations: (i) smoking behavior with number of teeth present, number of FTUs, decayed teeth, periodontal disease, oral malodor and salivary flow rate, (ii) drinking alcohol behavior with number of teeth present, number of FTUs, periodontal disease, oral malodor and salivary flow rate, (iii) eating breakfast behavior with periodontal disease, oral malodor and salivary flow rate, (iv) eating between-meal snack with number of teeth present, number of FTUs, decayed teeth and periodontal disease, (v) maintaining weight with number of teeth present, number of FTUs, periodontal disease and oral malodor, (vi) sleeping with number of teeth present, number of FTUs, periodontal disease, oral malodor and salivary flow rate, (vii) physical activity with periodontal disease and salivary flow rate. Good health practices were related with good oral health behaviors. Moreover, general health practices were associated with the clinical oral health status such as number of teeth present, decayed teeth, FTUs, periodontal disease, oral malodor and salivary flow rate. The elderly with good general health practices were considered to have good oral health status. Improving general health habits are suggested to lead to better oral health for the elderly, and vice versa.

Functional tooth units and nutritional status of older people in care homes in Indonesia

To investigate the relationship between functional tooth units (FTUs) and nutritional status. One hundred females (mean age: 72.4 ± 8.2 years) at four private care homes in Jakarta, Indonesia were interviewed and clinically examined. The oral examination included the assessment of teeth, prosthetic status, and number of FTUs. The total number of FTUs was further divided by tooth composition: natural tooth against natural tooth (NN-FTUs), natural tooth against denture (ND-FTUs), and denture against denture (DD-FTUs). Nutritional status was evaluated using the body mass index (BMI) and the Mini Nutritional Assessment (MNA). The mean numbers of teeth present, NN-FTUs, ND-FTUs, DD-FTUs, and total FTUs were 13.1 ± 10.4, 1.7 ± 3.0, 1.2 ± 3.3, 0.4 ± 1.2 and 3.3 ± 4.4, respectively. The mean BMI and MNA scores were 24.8 ± 5.0 and 22.6 ± 2.8, respectively. Subjects with a normal BMI had a significantly higher total number of FTUs (3.6 ± 4.6) compared with underweight subjects (0.1 ± 0.3). Subjects with a normal MNA had a significantly higher number of NN-FTU (2.6 ± 3.7) compared to those who were at risk or in a state of under-nutrition (1.2 ± 2.4). This study revealed significant relationships between the number of FTUs and nutritional status. Keeping the posterior occlusion should be emphasized in order to maintain good nutritional status in older subjects.

Association between education level and dentition status in Japanese adults: Japan public health center‐based oral health study

The aim of this study was to examine whether there is an educational gradient in dentition status among Japanese adults who are under the universal public health insurance system. Subjects were 1201 community residents aged 55-75years as of May 2005 who completed a self-administered questionnaire and had a standard clinical oral examination. Analysis focused on the association of three education levels (junior high school, senior high school, and any college or higher education) with dentition status. The proportion of subjects with 20 or more teeth (P<0.001), number of teeth present (P=0.037), number of filled teeth (P=0.016), and two types of functional tooth units (FTUs): FTUs with natural teeth (n-FTUs) (P<0.001) and FTUs with natural teeth and artificial teeth on implant-supported and fixed prostheses (nif-FTUs) (P<0.001) were significantly associated with education level after adjusting for confounders. The significant trend of these values in dental indexes indicated a poorer dentition status with a lower education level. The results suggest that the level of education has an independent impact on dentition status in a group of Japanese adults, even after taking into account oral health-related factors. Therefore, providing appropriate oral health information from an early age within a compulsory school education program appears necessary to enhance health literacy and lessen the inequalities in dental health by educational level.

Evaluation of a self‐assessed screening test for masticatory ability of Taiwanese older adults

The aim of this study was to evaluate a screening test based on a food intake questionnaire to discriminate the masticatory ability of Taiwanese older adults with 20 and more natural teeth and at least 8 functional tooth units (FTUs) from the masticatory ability of those with fewer than 20 natural teeth and 8 FTUs. The subjects were 2244 patients (mean age, 60.4±10.0 years) recruited from 23 counties and cities in Taiwan. Information about their demographic data, dentition, and masticatory ability was collected. Masticatory ability was measured for 23 food groups comprising 35 common Taiwanese foods, and receiver operation characteristic curve analysis was performed. The results showed that the final questionnaire included 14 food groups and a subject choosing 'difficult to eat' responses for 4 and more of these food groups had the same masticatory ability as individuals with fewer than 20 natural teeth and 8 FTUs. In conclusion, foods that are the most difficult to eat are not necessarily good discriminatory indicators. Hence, the 14-food group questionnaire can be considered the best screening test for masticatory ability of Taiwanese older adults in terms of the presence of 20 and more natural teeth and at least 8 FTUs.

Relationship between remaining teeth and self-rated chewing ability among population aged 45 years or older in Kaohsiung City, Taiwan

The purposes of this study were to (1) examine the relationship between the number of various types of healthy remaining natural teeth at different sites and self-rated chewing ability and (2) evaluate the relationship between the number of functional tooth units (FTUs), comprising functional natural teeth (FNT) or fixed prostheses, and self-rated chewing ability. A sample of 296 adults (122 men and 174 women), aged 45 years or older (average age, 56.6 ± 9.7), were recruited from seven dental clinics in Kaohsiung City. Dental information on the number and status of remaining teeth was obtained through examination by trained and calibrated dentists. Self-assessment of chewing ability (masticatory score) was evaluated with a self-administered questionnaire. Results showed that increased age is associated with a greater likelihood of difficulty in chewing. To avoid chewing difficulty, at least 24.7 FNT, 13.3 posterior-FNT, 8.1 units of natural tooth-FTUs, or 9.6 units of fixed tooth-FTUs must remain. Age and the number of healthy remaining teeth, including natural teeth and fixed prostheses, are key factors in chewing ability. Given that aging is unavoidable, the preservation of healthy remaining teeth plays a relatively important role in the maintenance of chewing ability among middle-aged and elderly people.

Oral Health Status and Chewing Ability is Related to Mini-Nutritional Assessment Results in an Older Adult Population in Thailand

In a cross-sectional study, we investigated the relationship of Mini-Nutrition Assessment (MNA) results with chewing ability tests and oral examinations (number of teeth present and functional tooth units (FTUs)). The participants were 612 older people (Mean [SD] age: 68.8 [5.9]). According to the MNA score, 25.1% of participants were categorized as having normal nutrition, 67.2% were categorized as at risk of malnourishment, and 7.7% were categorized as having malnutrition. The mean numbers of teeth present and FTUs were [15.5] and [8.9], respectively. The ANCOVA analyses adjusted for age and gender showed that participants with malnutrition had lower numbers of teeth present (8.8), FTUs (8.4), and chewing ability (6.8) than those with normal nutrition (13.3, 10.4 and 7.8) (p < 0.05). Nutritional status was associated with mean numbers of teeth present, FTUs, and chewing ability. Therefore, it was concluded that retention of natural teeth with appropriate numbers of FTUs by replacing missing teeth with dentures and improving chewing ability will help the reduce risk of malnutrition in older adults.

Functional tooth units

Functional tooth units

Association between Diabetes Mellitus and Oral Health Status in Japanese Adults

AimThe objective of this study was to analyze the oral health among Japanese adults, with and without diabetes mellitus.MethodologyThe subjects were 518 community residents aged 20 to 91 years in Japan, who participated in the “Akita health and nutrition survey” and the “Akita dental disease survey”, conducted in 2006. The surveys comprised a self-administered questionnaire, along with medical and dental examinations.ResultsUsing the community periodontal index (CPI), the mean numbers of sextants presenting codes 0, 1 and 2 were significantly lower in diabetics than non-diabetics among the 59 years or younger age group. Although the mean numbers of sextants with codes 0, 1 and 2 among the 60 to 69 years age group were lower, and sextants with a code X among the 59 years or younger age group were higher in diabetics than non-diabetics, no statistically significant differences were detected. The tendency of lower mean numbers of natural teeth and functional tooth units in diabetics than non-diabetics was observed, however no differences were statistically significant.ConclusionThe outcome of periodontal disease seemed to be influenced by the diabetic state to some degree, but a clear association between diabetes and oral health status was not found.

Category of functional tooth units in relation to the number of teeth and masticatory ability in Japanese adults

The purposes of this study were (1) to examine differences in dental status among various age groups, particularly, focusing on whether subjects retained 20 or more natural teeth, and (2) to investigate the relationship among dental status, the number and categories of functional tooth units (FTUs), and masticatory ability. A dental examination and self-administered questionnaire were conducted in a total of 2,164 residents aged 40 to 75 years who dwelt in Japan. The percentage of subjects with 20 and more natural teeth and their number of posterior teeth decreased with age. There was not much difference in the mean number of FTUs in subjects with and without 20 or more natural teeth, but those with 20 natural teeth had fewer numbers of FTUs than those with more than 20 natural teeth. The categories of the FTUs were extremely different. Subjects with 20 or more natural teeth had FTUs consisting mostly of natural to natural teeth. Subjects with 19 or fewer natural teeth had many FTUs consisting of removable prosthetic teeth. The subjective chewing ability test was significantly correlated with the number of natural teeth. Subjects could chew the higher number of test foods as the number of natural teeth increased. Not only the number of natural teeth but the categories of FTUs appear to be key factors of chewing ability. It is important to keep as many natural teeth as possible so that the person's categories of FTUs are mainly composed of natural to natural teeth to maintain better oral function.

Masticatory ability and functional tooth units in Japanese adults

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.

Tooth loss, chewing ability and quality of life

Middle-aged and older adults are retaining teeth and avoiding dentures, which should impact quality of life. The aims of our study were to investigate tooth loss and chewing ability and their association with oral- and general-health-related quality of life and life satisfaction. A random sample of 45- to 54-year-olds from Adelaide, South Australia, was surveyed by self-complete questionnaire in 2004-2005 (n = 879, response rate = 43.8%). Health-related quality of life was measured with the Oral Health Impact Profile 14-item version and EuroQol Visual Analogue Scale instruments and life satisfaction by the Satisfaction with Life Scale. Functional tooth units were recorded at oral examinations performed by calibrated dentists on 709 persons (completion rate = 80.7%). Number of functional teeth was positively associated with chewing ability (beta = 0.31, P < 0.01). In multivariate analyses, controlling for number of functional teeth and other explanatory variables spanning dental visit pattern, dental behaviour, socio-demographics and socio-economic status, chewing ability was negatively associated with oral-health-related impacts (beta = -0.37, P < 0.01) and positively associated with general health (beta = 0.10, P < 0.05) and well-being (beta = 0.16, P < 0.01). Chewing ability was related to oral-health-related quality of life and general health, possibly reflecting the impact of chewing on food choice and enjoyment of meals and diet, and also indicated the importance of oral health to general well-being.

Factors Associated with Masticatory Performance in Unilateral Distal Extension Removable Partial Denture Patients

Masticatory performance of denture patients is an outcome of the intricate inter-relationship between patient characteristics and denture construction. This study aimed to identify both patient- and denture-related factors associated with masticatory performance in unilateral distal extension removable partial denture patients (RPDs). Seventy-two patients (25 male and 47 female, mean age 63.4 +/- 6.7 years) with unilateral distal extension RPDs were included in the study. The Mixing Ability Index (MAI) obtained from a chewing test using standard two-colored wax cubes, determined masticatory performance. The effect of each evaluated factor on masticatory performance was first determined by an independent t-test or one-way analysis of variance. The statistically significant factors were entered in a model of multivariate linear regression analysis to estimate the independent effect on MAI. The MAI ranged from -3.06 to 0.80 (Mean -0.71 +/- 0.86). Univariate analyses identified male gender, high maximum bite force, more functional tooth units, and natural dentition opposing RPDs as patient factors increasing the MAI. Multivariate analysis (adjusted R(2)= 0.346) revealed that gender (p < 0.001), maximum bite force (p= 0.02), and number of functional tooth units (p= 0.03) were independent predictors for masticatory performance. None of the denture-related factors had a significant influence on MAI. Gender, maximum bite force, and number of functional tooth units were the main factors influencing masticatory performance of unilateral distal extension RPD patients.

Oral function and diet quality in a community-based sample.

Overall diet quality indices, such as the Healthy Eating Index (HEI), are preferred for epidemiological studies, yet studies in dentistry have focused on isolated dietary components. This study investigated the influence of socio-demographic and masticatory variables (masticatory performance, bite force, number of posterior functional tooth units, TMJ disorder, and dentition status) on overall diet quality in a community-based sample (n = 731). Cross-sectional data were derived from clinical examinations, bite force recordings, masticatory performance measurements, and two 24-hour dietary recalls. Females, European-Americans, and older subjects had better HEI scores than males, Mexican-Americans, and younger subjects, respectively. Income, education, and the masticatory variables were not related to diet quality. Analyses according to dentition status (good dentition, compromised dentition, partial denture, and complete dentures) showed no inter-group differences for HEI except for the age groups. The results suggest that the chewing-related factors evaluated in this sample are not predictors of overall diet quality across the socio-demographic groups.

Determinants of masticatory performance in dentate adults

Masticatory performance results from a complex interplay of direct and indirect effects, yet most studies employ univariate models. This study tested a multivariate model of masticatory performance for dentate subjects. Explanatory variables included number of functional tooth units, bite force, sex, age, masseter cross-sectional area, presence of temporomandibular disorders, and presence of diabetes mellitus. The population-based sample consisted of 631 dentate subjects aged 37–80 years. Covariance structure analysis showed that 68% of the variability in masticatory performance could be explained by the combined effects of the explanatory variables. Age and sex did not show a strong effect on masticatory performance, either directly or indirectly through masseter cross-sectional area, temporomandibular disorders, and bite force. Number of functional tooth units and bite force were confirmed as the key determinants of masticatory performance, which suggests that their maintenance may be of major importance for promoting healthful functional status.

Relationship between oral function and occlusal support in denture wearers

Patients with removable partial dentures or complete dentures do not demonstrate masticatory function to the same level as patients with a full set of natural teeth. The purpose of this study was to characterize the relationship between reduction of masticatory function, in terms of masticatory performance and bite force, and the existence of remaining natural occlusal supports as assessed by the Eichner index. One hundred and eighteen removable partial denture and complete denture wearers were selected for analyses. These subjects were divided into four groups depending upon the number of occlusal supports. Seventy dentate subjects with full occlusal support were designated as a comparison group. Bilateral bite force was measured at the first molar region in all subjects. Masticatory performance was assessed using the modified Masticatory Performance Index. Peanuts were used as the test food. Both bite force and masticatory performance were significantly associated with group classification. Moreover, both bite force and masticatory performance of the four denture groups were significantly reduced compared to the comparison group and this tendency was remarkable for the denture groups without occlusal support. These results suggest that the existence of functional tooth units may be a key factor in preservation of masticatory function.

Relationship between oral function and occlusal support in denture wearers

Patients with removable partial dentures or complete dentures do not demonstrate masticatory function to the same level as patients with a full set of natural teeth. The purpose of this study was to characterize the relationship between reduction of masticatory function, in terms of masticatory performance and bite force, and the existence of remaining natural occlusal supports as assessed by the Eichner index. One hundred and eighteen removable partial denture and complete denture wearers were selected for analyses. These subjects were divided into four groups depending upon the number of occlusal supports. Seventy dentate subjects with full occlusal support were designated as a comparison group. Bilateral bite force was measured at the first molar region in all subjects. Masticatory performance was assessed using the modified Masticatory Performance Index. Peanuts were used as the test food. Both bite force and masticatory performance were significantly associated with group classification. Moreover, both bite force and masticatory performance of the four denture groups were significantly reduced compared to the comparison group and this tendency was remarkable for the denture groups without occlusal support. These results suggest that the existence of functional tooth units may be a key factor in preservation of masticatory function.