A 5‐year longitudinal study of association of maximum bite force with development of frailty in community‐dwelling older adults

To determine whether maximum bite force (MBF), an objective measure of oral function, is associated with development of frailty in community‐dwelling older adults. This prospective cohort study included community‐dwelling Japanese adults aged 75 years at baseline (n = 322). Baseline MBF was measured using an electronic recording device (Occlusal Force‐Meter GM10). Follow‐up examinations, including physical fitness and anthropometric evaluation and structured questionnaires, were administered annually over a 5‐year period to determine the incidence of frailty, which was defined by the presence of 3 or more of the following 5 components derived from the Cardiovascular Health Study: low level of mobility, low physical activity level, weakness, shrinking and poor endurance and energy. Adjusted hazard ratios (HRs) of incidence of frailty according to sex‐stratified tertiles of baseline MBF were calculated using Cox proportional hazards regression models. During the follow‐up, 49 participants (15.2%) developed frailty. Participants in the lower tertile of MBF exhibited a significantly greater risk of frailty than those in the upper tertile. After adjustment for sex, depression, diabetes and Eichner index, the adjusted HRs for frailty in the upper through lower tertiles of MBF were 1.00 (reference), 1.27 (95% confidence interval [CI]: 0.50‐3.20) and 2.78 (95% CI: 1.15‐6.72), respectively (P for trend = .01). Poor oral function, as indicated by low MBF, increases the risk of development of frailty among elderly men and women.     

Estimation of the rate of tooth wear in permanent incisors: a cross‐sectional digital radiographic study

This study used conventional digital radiography to estimate the rate of tooth wear (TW) of maxillary and mandibular central incisors based on a cross‐sectional study design. The crown length of 1239 permanent maxillary and mandibular central incisors from 346 persons (age groups: 10, 25, 40, 55 and 70 years ±3) were measured by three calibrated dentists. Study teeth were intact incisally, had clearly visible incisal edges and cementoenamel junctions and had natural tooth antagonists. Measures were based on digital radiographic images (N = 666) archived in MiPACS within the electronic health record (axiUm^®) from the College of Dentistry patient database. Incisor crown length decreased at a linear rate in both arches over the 60 years represented by the age groups. The average crown length for maxillary incisors in the youngest age group was 11·94 mm, which decreased by an average of 1·01 mm by median age 70. For mandibular incisors, the average crown length in the youngest age group was 9·58 mm, which decreased by an average of 1·46 mm in the oldest age group. Males and females showed similar rates of TW. Regardless of age, females demonstrated smaller mean crown height for maxillary incisors than males (P < 0·0001). Measures by the examiners demonstrated good agreement, with an interclass correlation coefficient of 0·869 and an average intra‐examiner correlation of 99·5%, based on repeated measurements (n = 100). TW was estimated to average 1·01 mm for maxillary central incisors and 1·46 mm for mandibular central incisors by age 70 years.     

Effect of tongue position on masseter and temporalis electromyographic activity during swallowing and maximal voluntary clenching: a cross‐sectional study

The purpose of this study was to measure and compare the tonic electromyographic (EMG) activity of the temporalis and masseter muscles following placement of the tongue either on the palate or in the floor of the mouth during swallowing and maximal voluntary clenching (MVC). Thirty healthy dental students with natural dentition and bilateral molar support, between the ages of 18 and 22, with no prior history of oro‐facial injury, or current or past pain in the jaw, mouth or tongue participated in the study. Tonic masseter and temporalis EMG activities were recorded using surface electrodes. Subjects were instructed to passively place the tongue either on the anterior hard palate or in the floor of the mouth during swallowing and MVC. At each tongue position, the resulting EMG was recorded. During swallowing, no significant difference in EMG activity was found either for the masseter (P‐value = 0·1592) or the temporalis (P‐value = 0·0546) muscles, regardless of the tongue position. During MVC, there was a statistically significant difference for both the masseter (P‐value = 0·0016) and the temporalis (P‐value = 0·0277) muscles with lower levels recorded with the tongue in the floor of the mouth. This study found that in normal, pain‐free subjects, placing the tongue in the floor of the mouth significantly reduces masticatory muscle activity during MVC. Thus, it may be considered as a possible therapeutic option to decrease masticatory muscle activity; however, further research is needed in patients with oro‐facial pain.     

Tobacco smoking: a major risk factor for loss of teeth in three 70-year-old cohorts

Oral health was examined in a random sample of 1377 people in three 70-year-old cohorts studied within 5-yr intervals. During the studied period 1971-1983 the prevalence of toothlessness decreased from 52 to 34%. Toothlessness in men was more common in smokers, 48%, and ex-smokers, 32%, than in non-smokers, 20%. Eichner's index was used as a measurement of dental invalidity. This index showed a worse dental state among smokers and ex-smokers compared to non-smokers. Multivariate analyses indicated that tobacco smoking was a major independent risk factor for tooth loss in elderly men.     

Occurrence of peri‐implant diseases and risk indicators at the patient and implant levels: A multilevel cross‐sectional study

Background : High prevalence rates of peri‐implant diseases have been reported; however, the lack of standardization of definition criteria has lead to variations in the observed estimates. In addition, scarce data are available concerning patient and implant related factors associated to peri‐implantitis. The aim of this study was to determine the prevalence of peri‐implant diseases and their risk indicators at the patient and implant levels. Methods : One hundred forty‐seven patients with 490 dental implants were included. Dental implants were clinically and radiographically evaluated to determine their peri‐implant conditions. Patient‐related conditions and implant and prosthetic‐related factors were recorded. Multivariable Poisson regression was fitted and prevalence ratios (PR) were reported. Results : 85.3% of implants (95%CI 80.2 to 90.4) had mucositis and 9.2% (95%CI 4.7 to 13.7) had peri‐implantitis. 80.9% (95%CI 73.8 to 86.8), and 19.1% (95%CI 12.6 to 25.5) of patients had mucositis and peri‐implantitis. At the patient level, it was observed an increased probability of peri‐implantitis in individuals with pocket depths ≥6 mm (PR = 2.47) and with ≥4 implants (PR = 1.96). Smoking increased the probability of peri‐implantitis by three times (PR = 3.49). The final multilevel Poisson regression model at the implant level indicated that platform switching reduced the probability of peri‐implantitis (PR = 0.18) and implants in function for ≥5 years increased this probability (PR = 2.11). The final model including patient and implant level indicators demonstrated that higher time of function (PR = 2.76) and smoking (PR = 6.59) were associated with peri‐implantitis. C onclusion : Peri‐implant diseases are highly prevalent in the studied sample, and factors associated with the occurrence of peri‐implantitis were presence of pockets ≥6 mm, smoking, time of function, and type of platform.     

Association between underweight and taste sensitivity in middle‐ to old‐aged nursing home residents in Sri Lanka: a cross‐sectional study

Low taste sensitivity may be one factor related to undernutrition, which is a major problem in developing countries. The purpose of this cross‐sectional study was to examine the association between underweight, one indicator of undernutrition, and taste sensitivity in middle‐ to old‐aged Sri Lankan nursing home residents. Participants were 946 residents with BMI of <25·0 from 25 nursing homes. Data were obtained on height, weight, taste sensitivity, subjective taste ability, sex, age, ethnicity, number of years in nursing homes, activities of daily living (ADL), frequency of exercise, bowel movements, smoking status, drinking status, current number of chronic diseases, number and kinds of medications used, self‐reporting questionnaire 20 (SRQ20), subjective smell ability, number of teeth present, Eichner index and flow rate of saliva. Low sensitivity to bitter taste, being male, old age, low ADL, smoking experience, drinking experience, fewer medications used and no use of medication for hypertension and diabetes were each associated with underweight (P < 0·05). In a multilevel Poisson regression model adjusted for sex, age, ADL, smoking status, drinking status, number of medications used, use of medication for hypertension and diabetes and flow rate of saliva, subjects with low sensitivity (>0·003% quinine hydrochloride dihydrate) to bitter taste had a significant 1·70 times higher prevalence ratio (95% confident interval 1·04–2·80) for underweight compared with those with high sensitivity (0·0001% quinine hydrochloride dihydrate). These results suggest that low taste sensitivity to bitter taste may be one factor related to underweight.