23 research outputs found
On the Gaseous Exchange of Ammonia between Leaves and the Environment: Determination of the Ammonia Compensation Point
The Prevalence of Tooth Wear in the Dutch Adult Population
This study aimed to assess the prevalence of tooth wear in different age groups of the Dutch adult population and to determine this tooth wear distribution by gender, socioeconomic class, and type of teeth. Results were compared with the outcomes of a previous study in a comparable population. As part of a comprehensive investigation of the oral health of the general Dutch adult population in 2013, tooth wear was assessed among 1,125 subjects in the city of 's-Hertogenbosch. The data collected were subjected to stratified analysis by 5 age groups (25-34, 35-44, 45-54, 55-64, and 65-74 years), gender, socioeconomic class, and type of teeth. Tooth wear was assessed using a 5-point ordinal occlusal/incisal grading scale. The number of teeth affected was higher in older age groups. Men showed more tooth wear than women, and subjects with low socioeconomic status (low SES) showed on average higher scores than those with high SES. Tooth wear prevalence found in this study was higher in all age groups than in the previous study. The present study found prevalences of 13% for mild tooth wear and 80% for moderate tooth wear, leading to the conclusion that these are common conditions in the Dutch adult population. Severe tooth wear (prevalence 6%) may however be characterized as rare. A tendency was found for there to be more tooth wear in older age groups, in men as compared with women, in persons with lower SES, and in the present survey as compared with the previous one
Monitoring Tooth Wear
Tooth wear is a multifactorial condition leading to the irreversible loss of dental hard tissues. Although tooth wear is mainly a physiological process, it can become pathological if the wear process is accelerated for various reasons. Since this process is not linear, but can sometimes be inactive and sometimes active, a careful monitoring policy is necessary. The possible monitoring tools are described in this article, and a proposal is made with regard to the frequency of the systematic and periodic collection of information.</p
The prevalence of awake bruxism and sleep bruxism in the Dutch adolescent population
Objectives: This study aimed to assess the prevalence of awake bruxism and sleep bruxism in the Dutch adolescent population. Materials and Methods: As part of a large epidemiologic survey on oral health of the general Dutch adolescent population in 2017, a total of 920 subjects were asked about their bruxism behaviour during daytime and during sleep. The collected data were subjected to stratified analysis by two age groups (for 17 and 23Â years, respectively), gender and socio-economic status. Results: A prevalence of 4.1% and 4.2% was found for awake bruxism and of 7.6% and 13.2% for sleep bruxism. Women reported awake bruxism more often than men in the 17-year-old age group (5.0% and 3.2%, respectively), while in the 23-year-old age group it was the other way around (4.0% and 4.4%, respectively). Regarding sleep bruxism, women reported higher percentages than men in both age groups (7.8% versus 7.5% and 14.9% versus 11.5%, respectively). Concerning socio-economic status (SES), awake bruxism was more often found in high SES groups (4.6% versus 3.7% and 4.9% versus 4.0% in both age groups, respectively) as well as for sleep bruxism in the 23-year-old group (16.5% versus 8.6%). In the 17-year-old group, sleep bruxism was more often reported in the low SES group (9.7% versus 5.3%). Conclusions: Sleep bruxism is a common condition in the Dutch adolescent population, while awake bruxism is rarer. Clinical relevance: Dental caregivers can use this information when negative healthcare outcomes are present amongst adolescents
Towards a standardized tool for the assessment of bruxism (STAB) - overview and general remarks of a multidimensional bruxism evalution system
The aim of the present paper was to give an overview of the general project and to present the macrostructure of a comprehensive multidimensional toolkit for the assessment of bruxism, viz. a bruxism evaluation system. This is a necessary intermediate step that will be detailed in a successive extended publication and will ultimately lead to the definition of a Standardized Tool for the Assessment of Bruxism (STAB) as the final product. Two invitation-only workshops were held during the 2018 and 2019 General Session & Exhibition of the International Association for Dental Research (IADR) meetings. Participants of the IADR closed meetings were split into two groups, to put the basis for a multidimensional evaluation system composed of two main axes: an evaluation Axis A with three assessment domains (ie subject-based, clinically based and instrumentally based assessment) and an aetiological/risk factors Axis B assessing different groups of factors and conditions (ie psychosocial assessment; concurrent sleep and non-sleep conditions; drug and substance use or abuse; and additional factors). The work of the two groups that led to the identification of different domains for assessment is summarised in this manuscript, along with a road map for future researches. Such an approach will allow clinicians and researchers to modulate evaluation of bruxism patients with a comprehensive look at the clinical impact of the different bruxism activities and aetiologies. The ultimate goal of this multidimensional system is to facilitate the refinement of decision-making algorithms in the clinical setting
On the Gaseous Exchange of Ammonia between Leaves and the Environment: Determination of the Ammonia Compensation Point
Whole shoots of Phaseolus vulgaris L. and other species were exposed to a range of partial pressures of gaseous ammonia in air and the resulting fluxes were measured. Net uptake is linear with partial pressure in the range 5 to 50 nanobars and is zero at a finite partial pressure, termed the ammonia compensation point. Below the compensation point, ammonia (or possibly other volatile amines) is evolved by the leaves. The compensation points in several species are near the low partial pressures found in unpolluted air and approximate to the K(m) of glutamine synthetase in vitro. In P. vulgaris L., the compensation point increases with temperature
Tooth Wear Evaluation System (TWES) 2.0—Reliability of diagnosis with and without computer-assisted evaluation
Background: Tooth wear is a multifactorial process, leading to the loss of dental hard tissues. Therefore, it is important to detect the level of tooth wear at an early stage, so monitoring can be initiated. The Tooth Wear Evaluation System (TWES) enables such a multistage diagnosis of tooth wear. The further developed TWES 2.0 contains a complete taxonomy of tooth wear, but its reliability has not yet been validated. Objectives: The aim of the study was to examine in a randomised controlled trial (RCT) whether diagnoses made based on the TWES 2.0 are reproducible and whether this reproducibility is also achieved with computer-assisted diagnostics. Methods: 44 dental students received extensive training in TWES 2.0 assessment and taxonomy. The students each evaluated at least 10 (of the present 14) anonymised patient cases using gypsum models and high-resolution intra-oral photographs according to TWES 2.0. One half initially evaluated on paper; the other half used dedicated software (CMDfact / CMDbrux). After half of the patient cases (5), the evaluation methods were switched (AB/BA crossover design). The diagnoses were then evaluated for agreement with the predefined sample solution. Results: Evaluation of agreement with the sample solution according to Cohen's kappa indicated a value of 0.46 for manual (traditional) evaluation; and 0.44 for computer-assisted evaluation. Evaluation of agreement between examiners was 0.38 for manual and 0.48 for computer-assisted evaluation (Fleiss’ kappa). Conclusion: The results of this study proved that the taxonomy of the TWES 2.0 has acceptable reliability and can thus be used by dentists. Accordingly, the system can be learned quickly even by untrained practitioners. Comparable results are achieved with computer-assisted evaluation
Association between polysomnographic parameters of sleep bruxism and attrition-type tooth wear
Background: Clinically, sleep bruxism is considered to be associated with the presence of tooth wear, but strong evidence is still lacking. Objective: To examine whether an association exists between polysomnographic parameters, recorded from patients with possible sleep bruxism and tooth wear. Methods: Sixty-three possible sleep bruxers (19 males and 44 females, mean ± SD age = 38.5 ± 11.4 years) were recruited among patients attending the Clinic for orofacial pain and dysfunction of the Academic Centre for Dentistry Amsterdam (ACTA). The incisal/occlusal tooth wear was recorded for each tooth clinically, using a 5-point ordinal scale. Subsequently, all patients underwent an one-night ambulatory polysomnographic recording, during which the number of bruxism episodes per hour of sleep (Epi/h), the number of bruxism bursts per hour of sleep (Bur/h), and the bruxism time index (BTI) were recorded and analysed. Logistic regression analysis was performed using the presence of tooth wear as the dependent variable, the polysomnographic recordings as independent variables, and corrected for age and gender. The Bur/h and BTI were removed from the analyses due to collinearity with the Epi/h. Additionally, the polysomnographic recordings were also tested for possible association with self-reported grinding of the teeth during sleep. Results: No significant correlation was found between tooth wear and Epi/h (P = 0.381). In addition, the presence of tooth wear was not associated with self-reported parafunctions. Conclusion: Clinically measured tooth wear and self-reported parafunction seem not be related to the polysomnographic parameters of possible sleep bruxism
A methodology for evaluating tooth wear monitoring using timed automata modelling
Objectives: Tooth wear is a multifactorial condition leading to the loss of dental hard tissues. A counselling/monitoring protocol is of importance in order to keep that loss as limited as possible. Since many factors are involved and a time span of decades is included, research to disentangle all these processes in patients is difficult. Instead, a modelling technique was used that is able to deal with time, costs and probabilistic and stochastic information. The aim was to shed light on the question: does a yearly or a once-in-five-years counselling/monitoring protocol yield better outcome measures? Methods: A so-called timed automata model was adopted, analysed with the tool UPPAAL. To our knowledge, this is the first time that formal modelling is applied in dentistry. In this article, a UPPAAL model for the evaluation of tooth wear is described. Results: Using the UPPAAL model, it was calculated that with a yearly counselling/monitoring protocol the severity of tooth wear at age 74, the total costs per personand the number of restorative treatments were less, and the number of so-called“good years” was higher. Conclusions: With the use of the UPPAAL model, it may be concluded that a yearly counselling/monitoring protocol can yield better outcome measures. Clinical Significance: Regarding dentistry in general and tooth wear in particular, with the use of a timed automata model in UPPAAL, actual research questions can be answered, factors of influence in a multifactorial condition like tooth wear can be clarified, and future research topics can be determined