[Orofacial pain: a discipline on the brink of a new era]. / Orofaciale pijn: een vakgebied aan de vooravond van een nieuw tijdperk.

The orofacial pain discipline is on the brink of a new era. The introduction of a new definition of pain that, unlike the previous definition, also applies to individuals who cannot verbally express their pain, as well as the publication of the new international classification for orofacial pain, will contribute significantly to the improvement of the quality of the diagnostic process, thus increasing the chance of a successful treatment. Ultimately, the orofacial pain patient will emerge as the winner. The purpose of this article is to introduce the reader to these important recent developments and to provide him/her with an understanding of the implications of these developments for orofacial pain diagnosis and treatment in general and specialized dental practice.

[Parkinson's disease, temporomandibular disorders and bruxism: A pilot study]. / De ziekte van Parkinson, temporomandibulaire disfunctie en bruxisme.

Even though bruxism and Parkinson's disease have much in common, a possible relationship between them has not been established. The aim of this study was to gain more insight into a possible relationship between bruxism and temporomandibular disorders on the one hand and Parkinson's disease on the other. For this study, 708 people (368 with Parkinson's disease or parkinsonism and 340 controls) fully completed a questionnaire. The questionnaire included a selective Dutch translation of the questions from the Diagnostic Criteria for TMD (DC/TMD), complemented with a question about tooth wear. The chi-square test and independent samples t test were used for the data analysis. The results showed patients with Parkinson's disease or parkinsonism reported pain resulting from temporomandibular disorders and bruxism when asleep and awake significantly more often than the controls. When facial pain was reported, patients with Parkinson's disease or parkinsonism had a higher mean pain score than the controls. In conclusion, this study showed a relationship between Parkinson's disease or parkinsonism on the one hand and bruxism on the other. Furthermore, the study revealed a relationship between Parkinson's disease or parkinsonism on the one hand and pain resulting from temporomandibular disorders on the other.

International consensus on the assessment of bruxism: Report of a work in progress.

In 2013, consensus was obtained on a definition of bruxism as repetitive masticatory muscle activity characterised by clenching or grinding of the teeth and/or by bracing or thrusting of the mandible and specified as either sleep bruxism or awake bruxism. In addition, a grading system was proposed to determine the likelihood that a certain assessment of bruxism actually yields a valid outcome. This study discusses the need for an updated consensus and has the following aims: (i) to further clarify the 2013 definition and to develop separate definitions for sleep and awake bruxism; (ii) to determine whether bruxism is a disorder rather than a behaviour that can be a risk factor for certain clinical conditions; (iii) to re-examine the 2013 grading system; and (iv) to develop a research agenda. It was concluded that: (i) sleep and awake bruxism are masticatory muscle activities that occur during sleep (characterised as rhythmic or non-rhythmic) and wakefulness (characterised by repetitive or sustained tooth contact and/or by bracing or thrusting of the mandible), respectively; (ii) in otherwise healthy individuals, bruxism should not be considered as a disorder, but rather as a behaviour that can be a risk (and/or protective) factor for certain clinical consequences; (iii) both non-instrumental approaches (notably self-report) and instrumental approaches (notably electromyography) can be employed to assess bruxism; and (iv) standard cut-off points for establishing the presence or absence of bruxism should not be used in otherwise healthy individuals; rather, bruxism-related masticatory muscle activities should be assessed in the behaviour's continuum.

[European statement of consensus regarding the treatment of severe tooth wear]. / Europese consensusverklaring over de behandeling van ernstige gebitsslijtage.

In 2016, a European consensus meeting was held regarding the treatment of severe tooth wear. This meeting resulted in the publication of the European statement of consensus on the treatment of severe tooth wear in 2017. In the statement, new definitions of physiological and pathological tooth wear are described, recommendations for diagnosis and taking preventive measure are presented, and advice for counseling and monitoring is offered to better elucidate the underlying aetiological factors causing tooth wear in the patient. The decision whether restorative treatment is appropriate is multifactorial and partially dependent on the severity and the consequences of the wear and on the aesthetic and functional wishes of the patient. Restorative intervention should be delayed as long as possible, but when such intervention is indicated, the preference is for minimally invasive techniques using direct, indirect or hybrid treatment methods.

[The prevalence of tooth wear in the Dutch adult population]. / De prevalentie van gebitsslijtage onder de volwassen Nederlandse bevolking.

This study, performed in 2013, aimed to assess the prevalence of tooth wear in the Dutch adult population. The prevalence of tooth wear was not only determined for different age groups but also according to gender, socioeconomic status and types of teeth. Results were compared with the outcomes of a previous study in a comparable population in 2007. The data were collected as part of a comprehensive dental-epidemiological research project. The 1,125 adults from the city of 's-Hertogenbosch who participated in the project were subdivided into 5 age groups. Tooth wear was quantified using a 5-point ordinal occlusal/incisal grading scale. The number of teeth affected by tooth wear was higher in older age groups. Men showed more tooth wear than women, as did individuals with lower socioeconomic status, among whom a similar tendency was observed. Tooth wear prevalence found in 2013 was higher in all age groups than in 2007. One can conclude that tooth wear is a common condition in the Dutch adult population.

[Chewing on bruxism: associations, consequences and management]. / Kauwen op bruxisme. Associaties, gevolgen en behandeling.

In this second part of a diptych on bruxism, the focus is on the associations of this masticatory muscle activity with other sleep-related conditions. Its association with the obstructive sleep apnoea syndrome (OSAS) has been a particular object of study. Bruxism seems to play a protective role in OSAS, although the evidence for this is not yet conclusive. Apart from this possible positive consequence, bruxism also has several negative consequences, for which evidence is available to a greater or lesser extent. For example, bruxism has been associated with temporomandibular pain and dysfunction, periodontal and endodontic problems, failures of restorations and implants, and tooth wear. In some cases, these consequences are severe enough to justify treatment of bruxism. In all other cases, there is no indication for diagnostics and treatment, given the possible positive consequences. If treatment is indicated, modalities should be conservative, like stabilisation appliances, counselling, medication, psychology, and physiotherapy.

[Chewing on bruxism. Diagnosis, imaging, epidemiology and aetiology]. / Kauwen op bruxisme. Diagnostiek, beeldvorming, epidemiologie en oorzaken.

Since the publication of a special issue on bruxism of the NTvT in July 2000, consensus has been reached on bruxism's definition as a repetitive masticatory muscle activity that is characterised by clenching and/or grinding while awake (awake bruxism) or during sleep (sleep bruxism). As yet, however, no consensus exists about the diagnosis of bruxism: sufficient evidence to establish the reliability and validity of the commonly used techniques (self-report, clinical examination, imaging, electromyography, polysomnography) has not yet been produced. Morphological factors are no longer considered important aetiological factors, while increasing evidence suggests aetiological roles for psychosocial, physiological, biological, and exogenous factors. This review paper is the first part of a diptych and is concerned with the definition, diagnostics, epidemiology and possible causes of this disorder. In the second part, that will be published in the next issue, associations of bruxism with other conditions will be discussed, along with its (purported) consequences and its management.

Surface-Sensitive Microwear Texture Analysis of Attrition and Erosion.

Scale-sensitive fractal analysis of high-resolution 3-dimensional surface reconstructions of wear patterns has advanced our knowledge in evolutionary biology, and has opened up opportunities for translatory applications in clinical practice. To elucidate the microwear characteristics of attrition and erosion in worn natural teeth, we scanned 50 extracted human teeth using a confocal profiler at a high optical resolution (X-Y, 0.17 µm; Z < 3 nm). Our hypothesis was that microwear complexity would be greater in erosion and that anisotropy would be greater in attrition. The teeth were divided into 4 groups, including 2 wear types (attrition and erosion) and 2 locations (anterior and posterior teeth; n = 12 for each anterior group, n = 13 for each posterior group) for 2 tissue types (enamel and dentine). The raw 3-dimensional data cloud was subjected to a newly developed rigorous standardization technique to reduce interscanner variability as well as to filter anomalous scanning data. Linear mixed effects (regression) analyses conducted separately for the dependent variables, complexity and anisotropy, showed the following effects of the independent variables: significant interactions between wear type and tissue type ( P = 0.0157 and P = 0.0003, respectively) and significant effects of location ( P < 0.0001 and P = 0.0035, respectively). There were significant associations between complexity and anisotropy when the dependent variable was either complexity ( P = 0.0003) or anisotropy ( P = 0.0014). Our findings of greater complexity in erosion and greater anisotropy in attrition confirm our hypothesis. The greatest geometric means were noted in dentine erosion for complexity and dentine attrition for anisotropy. Dentine also exhibited microwear characteristics that were more consistent with wear types than enamel. Overall, our findings could complement macrowear assessment in dental clinical practice and research and could assist in the early detection and management of pathologic tooth wear.

[Painful temporomandibular dysfunctions: diagnosis and -treatment]. / Pijnlijke temporomandibulaire disfuncties: diagnose en behandeling.

Painful temporomandibular disorders (TMD pain) are common among the general population. The most common sub diagnoses are myalgia (jaw-muscle pain) and arthralgia (temporomandibular joint pain). The aetiology of TMD pain has a multifactorial nature, and its diagnosis and possible treatment often require a multidisciplinary approach. The most recent insights in the diagnosis and treatment of TMD pain are based on the multidisciplinary guideline 'Chronic Orofacial Pain' that was developed by the Dutch Society of Headache Patients and was published in 2013. Dentists are required to follow the recommendations of this guideline. The authorisation of the guideline by the relevant academic and professional associations in the Netherlands implies that restraint is advised when adopting diagnostic procedures and treatment modalities that are not or are insufficiently based on solid evidence.

A plea for the development of an universally accepted modular tooth wear evaluation system.

BACKGROUND: Tooth wear is considered an increasing oral health problem. Due to its multifactorial nature, recognizing and diagnosing of tooth wear is difficult but nevertheless important. Over the years, a wide variety of evaluation systems has been developed, yet none of them is universally accepted. This has implications for both research and clinical practice. DISCUSSION: This paper describes an in-depth analysis of four commonly used tooth wear evaluation systems, namely, the Eccles index, the Tooth Wear Index, the Lussi index, and the Basic Erosive Wear Examination. Comparing those systems revealed that despite several similarities, they differ considerably from each other. Notably, all four systems have their specific advantages and disadvantages. However, neither one of them meets all necessary characteristics of a hypothetical, broadly applicable tooth wear evaluation system. In fact, it is not realistic that a single system qualifies for all purposes (for example, diagnosing or monitoring individual patients, performing epidemiological studies, etc.). As a potentially feasible solution for this issue, the development of an evaluation system is recommended that consists of multiple, coherent modules, which cover different purposes.

[A PhD completed 6. Tooth Wear Evaluation System: development and applications]. / Hora est 6. Het Gebitsslijtage Beoordelingssysteem: ontwikkeling en toepassingen.

Numerous ranking systems exist for the quantification of tooth wear, each unfortunately with its own particular shortcomings. In this dissertation a new and very comprehensive tooth wear evaluation system is described. In it, the existing terminology is adapted to distinguish among mechanical-intrinsic (formerly attrition), mechanical-extrinsic (formerly abrasion), chemical-intrinsic (formerly erosion) and chemical-extrinsic (formerly erosion). In order to indicate the degree of wear, the terms mild, moderate, serious and severe are used. On the basis of previous systems, the terms, 3 degree-of-wear systems were developed and tested for reliability for use in the dentist's clinic, on dental models and oral imaging. The ranking scales were shown to be reliably applicable intra-orally, on the dental models and on the oral images, particularly on occlusal/incisal surfaces. The findings of this research have resulted in the formation of a modular Tooth Wear Evaluation System in order to quantify, qualify, monitor and establish the sources of tooth wear. The evaluation system can also be used to determine treatment options.

Assessment of the amount of tooth wear on dental casts and intra-oral photographs.

Tooth wear is a multifactorial condition, leading to the loss of dental hard tissues. Many grading scales are available to assess the amount of tooth wear, one of which is the tooth wear evaluation system (TWES). A grading scale can be used chairside, on casts and on photographs. The aim was to test whether the grading scales of the TWES, used on casts and on photographs, resulted in comparable scores. In addition, it was tested whether these scales can be used to assess tooth wear reliably on photographs. Of 75 tooth wear patients, sets of casts and series of photographs were obtained and graded. Comparison of the grading on casts and on photographs revealed equal median values and percentiles for both occlusal/incisal grading and non-occlusal/non-incisal grading. The grading on casts and on photographs showed a high correlation for the occlusal/incisal grading and a low correlation for the non-occlusal/non-incisal grading (Spearman's rho = 0·74 and rho = 0·47; P < 0·001). Concerning the grading on photographs, the interexaminer reliability was fair-to-good (ICC = 0·41 to ICC = 0·55) while the intra-examiner reliability was fair-to-good to excellent (ICC = 0·68 to ICC = 0·86) for the occlusal/incisal grading. For the non-occlusal/non-incisal grading, the interexaminer reliability was poor to fair-to-good (ICC = 0·22 to ICC = 0·59), while the intra-examiner reliability was fair-to-good to excellent (ICC = 0·64 to ICC = 0·82). It was concluded that the scores obtained with the grading scales of the TWES on casts and on photographs are comparable. The grading scales can be used in a reliable way on photographs, which is especially the case for occlusal/incisal grading.

The tooth wear evaluation system: a modular clinical guideline for the diagnosis and management planning of worn dentitions.

Tooth wear is a multifactorial condition, leading to the loss of dental hard tissues, viz. enamel and dentine. Tooth wear can be divided into the subtypes mechanical wear (attrition and abrasion) and chemical wear (erosion). Because of its multifactorial aetiology, tooth wear can manifest itself in many different representations, and therefore, it can be difficult to diagnose and manage the condition. A systematic approach is a sine qua non. In the below-described tooth wear evaluation system (TWES), all necessary tools for a clinical guideline are present in different modules. This allows the dental clinician, in a general practitioner setting as well as in a referral practice setting, to perform a state-of-the-art diagnostic process. To avoid the risk of a too cumbersome usage, the dental clinician can select only those modules that are appropriate for a given setting. The modules match with each other, which is indispensable and essential when different modules of the TWES are compared. With the TWES, it is possible to recognise the problem (qualifying), to grade its severity (quantifying), to diagnose the likely causes and to monitor (the progress of) the condition. In addition, a proposal for the classification of tooth wear is made. Further, it is possible to determine when to start a treatment, to make the decision which kind of treatment to apply and to estimate the level of difficulty of a restorative treatment.

Psychometric properties of the Dutch version of the Orofacial Esthetic Scale (OES-NL) in dental patients with and without self-reported tooth wear.

The aim of this study was to test the psychometric properties of the Dutch version of the Orofacial Esthetic Scale (OES) in dental patients with and without self-reported tooth wear. The English version of the OES was translated into Dutch, following established guidelines for cross-cultural adaptation of health-related quality of life measures. The reliability of the resulting OES-NL was tested in a test-retest study on 343 subjects; its validity was tested with the use of convergent validity on 582 subjects. The test-retest reliability of the OES-NL showed intra-class correlation coefficients (ICC) that ranged from 0·76 to 0·82, which can be qualified as excellent. The Cronbach's alpha revealed that the overall internal consistency of the scale was good (α = 0·89). Convergent validity was confirmed by the association between the OES-NL summary scores and three questions of the Dutch version of the Oral Health Impact Profile (OHIP-NL). The calculated Spearman's rank correlation coefficients ranged from -0·43 to -0·54 and were all significant (P < 0·001). The Dutch version of the Orofacial Esthetic Scale (OES-NL) showed good psychometric properties, making it suitable for the assessment of self-perceived aesthetics in Dutch dental patients with and without self-reported tooth wear.

Assessment of the progression of tooth wear on dental casts.

Many methods are available for the grading of tooth wear, but their ability to assess the progression of wear over time has not been studied frequently. The aim was to assess whether the occlusal/incisal grading scale of the Tooth Wear Evaluation System (TWES) was sensitive enough for the detection of tooth wear progression from 14 to 23 years of age. A total of 120 sets of dental casts were gathered from 40 people, of whom impressions were made at 14, 18 and 23 years. The TWES was used to assess loss of clinical crown height throughout the entire dentition. There was a significant difference in the TWES scores between the three age groups on all teeth (Friedman tests; P < 0.005 in all cases). Post hoc Wilcoxon tests revealed that the difference between the scores between 14 and 18 years and between 18 and 23 was significant for most teeth. It was concluded that the TWES is sensitive enough to detect changes in tooth wear over time.

[Considerations in the treatment of tooth wear]. / Overwegingen bij de behandeling van gebitsslijtage.

Since the origin of tooth wear (attrition, abrasion and erosion) is multi-factorial, its diagnosis is complicated but vital. The so-called Tooth Wear Evaluation System, introduced earlier, makes a systematic diagnostic approach possible. The system consists of various modules, which can be used by the practitioner depending on the goal. Two new modules have been added to the Tooth Wear Evaluation System. The Therapy Start Module can be used to determine which one of the possible treatment modalities (counseling, monitoring, or restorative treatment) should be chosen. The Level of Difficulty Module gives the practitioner indications of the level of difficulty that may be encountered during a restorative treatment.

[Tooth wear, a proposal for an evaluation system]. / Een beoordelingssysteem voor gebitsslijtage.

The present-day terminology and definitions of tooth wear are not unambiguous. For diagnosing tooth wear, however, it is essential that they are unambiguous. In this article a proposal is presented for a tooth wear evaluation system with simplified definitions. This system consists ofa number of modules and can be used for various aspects of the diagnostic procedure. It can be used for the quantification of tooth wear, both for periodic screening and for the monitoring of tooth wear in individual patients. The scoring of occlusal/incisal tooth wear as well as of non-occlusal/non-incisal tooth wear is possible. The evaluative system is also suitable for determining which type of tooth wear, such as attrition, abrasion and erosion, is most likely to have caused any observed loss of hard tooth tissue.