Age assessment in the living using modified Gustafson's criteria in a northern Chinese population.

Regressive dental changes appear to be suitable for age assessment in living adults. In 2012, Olze et al. showed that several criteria presented by Gustafson for extracted teeth can also be applied to orthopantomograms. The objective of this study was to test the applicability and reliability of this method in a Chinese population. For this purpose, 1300 orthopantomograms of 650 female and 650 male Chinese aged between 15 and 40 years were evaluated. The characteristics of secondary dentin formation, periodontal recession, attrition, and cementum apposition were reviewed in all the mandibular premolars. The sample was split into a training and test dataset. Based on the training set, the correlation of the individual characteristics with chronological age was studied with a stepwise multiple regression analysis, in which individual characteristics formed the independent variable. According to the results, the R values amounted to 0.80 to 0.83; the standard error of estimate was 4.29 to 4.75 years. By analyzing the test dataset, the accuracy of the present study, Olze's and Timme's formulas were determined by the difference between the estimated dental age (DA) and chronological age (CA). Taking both mean differences and mean absolute differences into account, the Chinese age estimation formula did not always perform better compared with Olze's and Timme's formulas for both males and females. It was concluded that this method can be used in Chinese individuals for age assessment. However, the applicability of the method is limited by the quality of the X-ray images, and the method should only be applied by experienced forensic odontologists.

Relación entre la recesión ósea y atrición en cráneos secos contemporáneos / Relationship between bone recession and attrition in contemporary dry skulls

Objetivos: El objetivo de éste estudio és observar la posible influencia de las fuerzas oclusales según el grado de atrición de las piezas dentarias sobre la altura de la cresta alveolar. Material y métodos: Se estudiaron dientes de cráneos secos de la época actual y secomparó el desgaste oclusal ó atrición (A) con la pérdida de altura de la cresta alveolar (CA) ó recesión ósea (RO) y ambos registros se relacionaron estadísticamente. Resultados: De todos los dientes estudiados 2 tuvieron grado de atrición (GA) 0, 170 grado 1, 96 grado 2 y 15 grado 3. Registrando la recesión ósea (RO) las medidas extremas promedio estuvieron entre 2,80mm y 5,30mm; la mayor RO promedio se encontró en la parte media de las caras libres (pieza 23) y la menor en distal (pieza 11). Conclusión: No hay correlación entre la recesión ósea y el desgaste oclusal ó atrición.

Aim: The aim of these work is to know the relaciònship between the bonerecessiòn and the attritiòn.Materials and methods: We taken 228 teeth belonging to 25 dry skullsof actual edge and we compare the bone recession (BR) with the occlusalwaer or attrition (A) and both to be related with a statistical analyses.Results: Of all the teeth studied, 2 had attrition degree 0, 170 degree 1,96 degree 2 y 15 degree 3. Regarding the BR the measures differ between2,80 to 5,30mm. The BR major average was in the middle of the free aspect(tooth 23) and the minor in distal (tooth 11).Conclusion: There are not correlation between bone recession andocclusal wear or attrition.

Functional occlusal patterns during lateral excursions in young adults.

STATEMENT OF PROBLEM: A valid system for assessing and classifying functional occlusion has not been established. The prevalence of anterior protected articulation is not known. PURPOSE: The purpose of this study was to quantify the prevalence of various functional occlusal contact patterns, including anterior protected articulation, among dental students. MATERIAL AND METHODS: Occlusal contacts were examined during lateral excursions from the maximal intercuspal position to the canine-to-canine position in 100 young adults. A combination of 3 common clinical methods was used: a visual examination, articulating paper, and feedback from the participants. RESULTS: Data from 3 classification systems were analyzed: (1) Occlusal contacts on the working side only ­ canine protected articulation was present in 25% of laterotrusions; anterior protected articulation was present in 18.5% of laterotrusions. Group function was present in 56% of laterotrusions. Other schemes were present in 0.5% of laterotrusions. (2) Contacts on both the working and the nonworking side. (3) Contacts on the working and nonworking side during both right and left laterotrusion. Nonworking side contacts were present in 33% of the participants. Nonworking side interference was present in 1 participant. CONCLUSIONS: The prevalence of anterior protected articulation found in this study was high enough to allow anterior protected articulation to be considered one of the fundamental working side occlusal contact patterns. More studies will be necessary to confirm this finding.

Prevalence of dental erosion in young adults aged 18 years in Poland.

AIM: The aim of this study was to assess the prevalence of tooth wear in young adults in Poland. METHODS: A total of 1,886 persons aged 18 years, selected on a basis of multistage sampling, were examined within the Nationwide Dental Health Monitoring Programme. Previously calibrated dentists measured tooth wear using the BEWE-scoring system (Basic Erosive Wear Examination). RESULTS: Out of 1,886 young adults, 42.2% presented the signs of dental erosion. Considered the severity of erosion, it was graded as 1, 2 and 3 in 28.9%, 11.9% and 1.5% of 18-year-olds, respectively. CONCLUSIONS: Results of clinical assessment of dental erosion in 18-year-old young adults revealed that erosive tooth wear is an important problem in this age group. Of them, 13.4% had signs of advanced tooth wear which may lead to serious clinical problems in the future.

Validation of the Basic Erosive Wear Examination.

The Basic Erosive Wear Examination (BEWE) is a practical index for screening tooth wear, using a 4-point ordinal scale (0-3). The highest score is recorded in each sextant and a total score (or BEWE sextant cumulative) is calculated per subject. This study aims to investigate if the BEWE sextant cumulative score compares to one comprising a percentage score from all tooth surfaces and as a highest BEWE per subject. The aim is to assess the validity of this score. A total of 350 subjects were recruited from hospital and general practice in south-east England. Buccal, occlusal and lingual/palatal BEWE scores were collected and percentages calculated based on scores 1, 1 and above, 2 and above and 3. BEWE sextant cumulative scores and highest BEWE scores were also recorded per subject. Spearman's correlation coefficients (p values) assessed the relationship between BEWE sextant cumulative scores, BEWE percentages and BEWE highest score per subject. The BEWE sextant cumulative score correlates significantly to a BEWE score taken as a percentage score from all tooth surfaces (Spearman's r > 0.5, p < 0.001) and especially to BEWE surface scores of 1 and above and 2 and above (r > 0.8, p < 0.001) and as a highest surface score per subject (r > 0.8, p < 0.001). BEWE sextant score provides a representation of tooth wear on all tooth surfaces. This study validates a tooth wear index, which provides clinicians with risk indicators of a patient's level of tooth wear and may help to guide clinical management.

Coincidence and awareness of oral parafunctions in college students.

OBJECTIVE: The aim of the study was to determine the prevalence and awareness of particular types of oral parafunctions in young healthy students and any association with temporomandibular disorders (TMD). MATERIAL AND METHODS: The study was performed in a randomly selected group of 303 healthy students (mean age 18.8 years) from the vocational technical school in Wroclaw, Poland, who underwent a routine clinical examination and functional analysis of the mouth. On taking the history all subjects were asked about their awareness of various forms of parafunctional activity in their mouth. RESULTS: Almost all subjects revealed various oral parafunctions such as: bruxism, nail and pen biting, chewing gum, and biting the mucosa of lip or cheek. These habits were present singly or as double, triple or even fourfold coincidences in a single person. The most frequent oral parafunctions were habitual gum chewing and bruxism. Subjects were very seldom aware of the last parafunction. TMDs were more prevalent in the presence of bruxism than in other oral parafunctions. CONCLUSIONS: The studied students revealed various types of oral parafunctions, however most of them were not aware of clenching and grinding their teeth.

The problem with an epidemiological index for dental erosion.

This article reviews and discusses the difficulties posed by the application of epidemiological indices for the measurement of dental erosion. It covers several aspects of index design.

[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.

Degenerative changes in human temporomandibular joints in relation to occlusal support.

OBJECTIVE: Controversy exists concerning the etiological factors behind degenerative changes in the temporomandibular joints (TMJs). Tooth attrition, occlusal support, food consistency, ageing, gender and genetics are some possible causative factors that have been discussed in the literature. The aim of this study was to examine contemporary human skull material for possible relations between degenerative form and surface changes in the TMJs in relation to occlusal support. MATERIAL AND METHODS: The material consisted of 259 human skulls from 170 males and 89 females, with an age range of 18-100 years. RESULTS: Dental status was in general poor, and 22% of skulls were edentulous. Form and surface changes of both the condyles and the temporal components were more common in the present material compared to that in most previous studies. In males, irrespective of age, only weak and clinically insignificant correlations could be found between degenerative TMJ changes and occlusal support. In women, however, the correlations between these variables were in general much stronger, especially at higher ages. CONCLUSIONS: The present findings do not lend support to the hypothesis that loss of occlusal support is a causative factor for degenerative changes in the TMJs in male subjects. In women, such a correlation was obvious in the present sample, at least at higher ages. It can be speculated that hormonal factors play a role in the sex difference found.

Reliability of an occlusal and nonocclusal tooth wear grading system: clinical use versus dental cast assessment.

The reliability of a newly developed tooth wear grading system was assessed both clinically and on dental casts by two observers using 20 participants. The reliability of clinical occlusal/incisal tooth wear grading was fair-to-good to excellent, while that of most of the clinical nonocclusal/nonincisal grades was at least fair-to-good. Dental cast assessment frequently yielded poor reliabilities, especially for nonocclusal/nonincisal surfaces. Hence, occlusal/incisal wear could be graded more reliably than nonocclusal/nonincisal wear, while the clinical assessment of tooth wear was more reliable than the grading of dental casts.

A new index of tooth wear. Reproducibility and application to a sample of 18- to 30-year-old university students.

A modified wear index, in which the wear of enamel and dentine are recorded separately, is described. The index was applied to estimating the prevalence and extent of tooth wear in a single convenience sample of 18- to 30-year-old students attending a university in London. The subjects were examined under good lighting in a dental chair away from a dental school. A total of 707 females and 303 males were recruited with a mean age of 21.9 years (standard deviation = 0.1, range = 18-30) and examined by 3 trained and calibrated examiners. Intra-examiner intra-class correlation coefficients showed a range of 0.44-0.88. The unweighted kappa scores were above 0.88 for enamel and dentine. The presence of enamel wear was common to all subjects, but 6.1% of the participants had more than one third of the tooth surface affected. Dentine was exposed on 5.3% of all surfaces, with the largest proportion accounting for less than 10% of the tooth surface (grade 1). The proportion of subjects with at least 1 surface with dentine exposed was 76.9% of the total population. The males had significantly more wear in dentine than the females (p = 0.001). The inter-examiner intra-class correlation coefficients for enamel and dentine were 0.87 and 0.92, respectively. The reproducibility of the index was comparable to other analyses and provides an opportunity to assess the prevalence of enamel wear in large population-based studies.

Quantitative measurement of tooth and ceramic wear: in vivo study.

PURPOSE: The aim of this study was to quantitatively measure tooth and ceramic wear over a 2-year period using a novel superimposition technique. Three ceramic systems--experimental hot-pressed ceramic (EC), Procera AllCeram (PA), and metal-ceramic--were used. MATERIALS AND METHODS: A total of 90 posterior crowns in 48 patients were randomized into 3 groups, and impressions were made at baseline and at 6-month intervals for 2 years. Clinical images were taken after using a dye to highlight surface changes. The impressions were digitized and modeled as superimposable 3-dimensional colored surface images. The depth of wear at the occlusal contact areas was quantitatively measured at 6, 12, 18, and 24 months. RESULTS: The quantitative evaluation showed more wear in Procera AllCeram at the occlusal contact areas, whereas the experimental and metal-ceramic systems showed less wear. There was a significant difference in the amount of enamel worn between all types of restorations (P < .05). There was a statistically significant difference (P < .05) in the mean depth of wear between all systems. CONCLUSIONS: The metal-ceramic and experimental systems showed less change, indicating improved wear resistance compared with Procera AllCeram. In addition, enamel opposing metal-ceramic and experimental crowns showed less wear compared to enamel opposed by Procera AIICeram crowns.

Basic Erosive Wear Examination (BEWE): a new scoring system for scientific and clinical needs.

A new scoring system, the Basic Erosive Wear Examination (BEWE), has been designed to provide a simple tool for use in general practice and to allow comparison to other more discriminative indices. The most severely affected surface in each sextant is recorded with a four level score and the cumulative score classified and matched to risk levels which guide the management of the condition. The BEWE allows re-analysis and integration of results from existing studies and, in time, should initiate a consensus within the scientific community and so avoid continued proliferation of indices. Finally, this process should lead to the development of an internationally accepted, standardised and validated index. The BEWE further aims to increase the awareness of tooth erosion amongst clinicians and general dental practitioners and to provide a guide as to its management.

Current erosion indices--flawed or valid? Summary.

The problem of erosive tooth wear appears increasingly to be encountered by clinicians and researchers. An adequate way of defining and recording erosive tooth wear is essential in order to assess the extent of this clinical phenomenon, both on an individual level and in the population, and for the adequate provision of preventive and therapeutic measures. Well-established erosion indices have been used in most of these studies, although in many cases modifications have been made to suit the different research aims. This use of different indices is one reason why it still cannot be claimed that there is enough current knowledge on this clinical phenomenon. This article summarises the proceedings of a workshop to discuss the topic of dental erosion indices. The result of the workshop is the proposal for a new scoring system (Basic Erosive Wear Examination, BEWE) designed for use both within the research field and for dental clinicians, with the aims of standardising assessment of erosion for international comparisons, raising awareness and providing guidelines for treatment of erosive tooth wear in dental practice.

Methodological considerations concerning the development of oral dental erosion indexes: literature survey, validity and reliability.

Within the context of preventing non-communicable diseases, the World Health Report (2002) and the WHO Global Oral Health Program (2003) put forward a new strategy of disease prevention and health promotion. Greater emphasis is placed on developing global policies in oral health promotion and oral disease prevention. The Decayed, Missing, Filled Teeth (DMFT) index does not meet new challenges in the field of oral health. Dental erosion seems to be a growing problem, and in some countries, an increase in erosion of teeth is associated with an increase in the consumption of beverages containing acids. Therefore, within a revision of the WHO Oral Health Surveys Basic Methods, new oral disease patterns, e.g. dental erosion, have to be taken into account. Within the last 20 years, many studies on dental erosion have been carried out and published. There has been a rapid growth in the number of indexes quantifying dental erosion process in different age groups. However, these indexes are not comparable. This article discusses quality criteria which an index intended for assessing tooth erosion should possess.

How valid are current diagnostic criteria for dental erosion?

In principle, there is agreement about the clinical diagnostic criteria for dental erosion, basically defined as cupping and grooving of the occlusal/incisal surfaces, shallow defects on smooth surfaces located coronal from the enamel-cementum junction with an intact cervical enamel rim and restorations rising above the adjacent tooth surface. This lesion characteristic was established from clinical experience and from observations in a small group of subjects with known exposure to acids rather than from systematic research. Their prevalence is higher in risk groups for dental erosion compared to subjects not particularly exposed to acids, but analytical epidemiological studies on random or cluster samples often fail to find a relation between occurrence or severity of lesions and any aetiological factor. Besides other aspects, this finding might be due to lack of validity with respect to diagnostic criteria. In particular, cupping and grooving might be an effect of abrasion as well as of erosion and their value for the specific diagnosis of erosion must be doubted. Knowledge about the validity of current diagnostic criteria of different forms of tooth wear is incomplete, therefore further research is needed.

Is diagnosing exposed dentine a suitable tool for grading erosive loss?

Quantifying tooth wear in general and erosion in particular mostly is made by distinguishing between lesions restricted to enamel and lesions reaching the underlying dentine. Various scores for grading have been used, but in all systems, higher scores are given in cases of exposed dentine, thus, indicating a more severe stage of the condition. Clinical diagnosis of exposed dentine is made by assessing changes in colour or optical properties of the hard tissues. This paper aims to review the literature and discuss critically problems arising form this approach. It appears that classifying the severity of erosion by the area or depth of exposed dentine is difficult and poorly reproducible, and taking into account the variation of enamel thickness, the amount of tissue lost often is not related simply to the area of exposed dentine. There has still been very little longitudinal investigation of the significance of exposed dentine as a prognostic indicator. Further work and discussion is needed to reevaluate the explanative power of current grading procedures.

Tooth wear: the view of the anthropologist.

Anthropologists have for many years considered human tooth wear a normal physiological phenomenon where teeth, although worn, remain functional throughout life. Wear was considered pathological only if pulpal exposure or premature tooth loss occurred. In addition, adaptive changes to the stomatognathic system in response to wear have been reported including continual eruption, the widening of the masticatory cycle, remodelling of the temporomandibular joint and the shortening of the dental arches from tooth migration. Comparative studies of many different species have also documented these physiological processes supporting the idea of perpetual change over time. In particular, differential wear between enamel and dentine was considered a physiological process relating to the evolution of the form and function of teeth. Although evidence of attrition and abrasion has been known to exist among hunter-gatherer populations for many thousands of years, the prevalence of erosion in such early populations seems insignificant. In particular, non-carious cervical lesions to date have not been observed within these populations and therefore should be viewed as 'modern-day' pathology. Extrapolating this anthropological perspective to the clinical setting has merits, particularly in the prevention of pre-mature unnecessary treatment.