Anterior Tooth Wear Research Articles

Anterior dental evolution in the Australopithecus anamensis-afarensis lineage.

Australopithecus anamensis is the earliest known species of the Australopithecus-human clade and is the likely ancestor of Australopithecus afarensis. Investigating possible selective pressures underlying these changes is key to understanding the patterns of selection shaping the origins and early evolution of the Australopithecus-human clade. During the course of the Au. anamensis-afarensis lineage, significant changes appear to occur particularly in the anterior dentition, but also in jaw structure and molar form, suggesting selection for altered diet and/or food processing. Specifically, canine tooth crown height does not change, but maxillary canines and P(3)s become shorter mesiodistally, canine tooth crowns become more symmetrical in profile and P(3)s less unicuspid. Canine roots diminish in size and dimorphism, especially relative to the size of the postcanine teeth. Molar crowns become higher. Tooth rows become more divergent and symphyseal form changes. Dietary change involving anterior dental use is also suggested by less intense anterior tooth wear in Au. afarensis. These dental changes signal selection for altered dietary behaviour and explain some differences in craniofacial form between these taxa. These data identify Au. anamensis not just as a more primitive version of Au. afarensis, but as a dynamic member of an evolving lineage leading to Au. afarensis, and raise intriguing questions about what other evolutionary changes occurred during the early evolution of the Australopithecus-human clade, and what characterized the origins of the group.

Quantification of tooth wear: Conventional vs new method using toolmakers microscope and a three-dimensional measuring technique

Objectives This study aimed to evaluate the reliability of a new CAD-CAM Laser scanning machine in detection of incisal tooth wear through a 6-month period and to compare the accuracy of using this new machine against measuring tooth wear using tool maker microscope and conventional tooth wear index. Methods Twenty participants (11 males and 9 females, mean age = 22.7 years, SD = 2.0) were assessed for incisal tooth wear of lower anterior teeth using Smith and Knight clinical tooth wear index (TWI) on two occasions, the study baseline and 6 months later. Stone dies for each tooth were prepared and scanned using the CAD-CAM Laser Cercon System (Cercon Smart Ceramics, DeguDent, Germany). Scanned images were printed and examined under a toolmaker microscope (Stedall-Dowding Machine Tool Company, Optique et Mecanique de Precision, Marcel Aubert SA, Switzerland) to quantify tooth wear and then the dies were directly assessed under the microscope to measure tooth wear. The Wilcoxon Signed Ranks Test was used to analyse the data. Results TWI scores for incisal edges were 0, 1, and 2 and were similar at both occasions. Scores 3 and 4 were not detected. Wear values measured by directly assessing the dies under the tool maker microscope (range = 517–656 μm, mean = 582 μm, and SD = 50) were significantly more than those measured from the Cercon digital machine images (range = 132–193 μm, mean = 165 μm, and SD = 27) and both showed significant differences between the two occasions. Conclusions Measuring images obtained with Cercon digital machine under tool maker microscope allowed detection of wear progression over the 6-month period. However, measuring the dies of worn dentition directly under the tool maker microscope enabled detection of wear progression more accurately. Conventional method was the least sensitive for tooth wear quantification and was unable to identify wear progression in most cases.

Tooth wear and dental pathology of the Bronze–Iron Age people in Xinjiang, Northwest China: Implications for their diet and lifestyle

Tooth wear and dental pathology related to diet and lifestyle were investigated in the human dental remains unearthed from three archaeological sites of Bronze Age and Iron Age in Xinjiang of northwest China, and in comparative samples from two Neolithic sites in Henan and Shanxi in central China along the Yellow River. Our results indicate that the average tooth wear on most tooth types in the three Xinjiang sites was close to those of the Neolithic samples from central China. The variation within the Xinjiang samples was also explored. Some special wear patterns such as severe wear on the first molar and relatively heavy wear of anterior teeth were observed on the specimens from the Xinjiang sites. Obvious differences in caries and antemortem tooth loss were found between Xinjiang and comparative samples with higher frequencies of caries observed in samples from central China and higher antemortem tooth loss in samples from the Xinjiang sites. Strongly developed exostoses (tori) were also identified on mandibles and maxillae of the specimens from Xinjiang. The authors believe that the differences in tooth wear and dental pathology between Xinjiang and central China were caused by differences in diet and lifestyle. Food of a harder texture was consumed by the people who lived in Xinjiang than by the people in Henan and Shanxi of central China. The higher occurrence of heavily worn anterior teeth and some other special wear patterns, antemortem tooth loss and presence of exostoses on jaw bones in Xinjiang suggest that the people in Xinjiang lived in a relatively harsh environment, frequently gnawing hard objects, or using teeth as some kind of tools. All these activities put masticatory organs under a heavy load. The differences in caries frequencies between the frontier and central areas of China indicate that food richer in carbohydrates was consumed by the people in the central areas. It is proposed that about 3000–2000 years BP in many areas of frontier Xinjiang, people mainly relied on the type of hunter-gatherer economy with agriculture playing a smaller role in their lifestyle.

Occlusion and Temporomandibular Function among Subjects with Mandibular Distal Extension Removable Partial Dentures

Objective. To quantify effects on occlusion and temporomandibular function of mandibular distal extension removable partial dentures in shortened dental arches. Methods. Subjects wearing mandibular extension removable partial dentures (n = 25) were compared with subjects with shortened dental arches without extension (n = 74) and with subjects who had worn a mandibular extension removable partial denture in the past (n = 19). Subjects with complete dentitions (n = 72) were controls. Data were collected at baseline and at 3-, 6-, and 9-year observations. Results. Occlusal activity in terms of reported awareness of bruxism and occlusal tooth wear of lower anterior teeth did not differ significantly between the groups. In contrast, occlusal tooth wear of premolars in shortened dental arches with or without extension dentures was significantly higher than in the controls. Differences amongst groups with respect to signs and symptoms related to temporomandibular disorders were not found. Occlusal support of the dentures did not influence anterior spatial relationship. Occlusal contacts of the denture teeth decreased from 70% for second premolars via 50% for first molars, to 30% for second molars. Conclusions. Mandibular distal extension removable partial dentures in moderate shortened dental arches had no effects on occlusion and temporomandibular function.

Full mouth rehabilitation of the patient with severely worn dentition: a case report

The severe wear of anterior teeth facilitates the loss of anterior guidance, which protects the posterior teeth from wear during excursive movement. The collapse of posterior teeth also results in the loss of normal occlusal plane and the reduction of the vertical dimension. This case report describes 77-year-old female, who had the loss of anterior guidance, the severe wear of dentition, and the reduction of the vertical dimension. Occlusal overlay splint was used after the decision of increasing vertical dimension by anatomical landmark, facial and physiologic measurement. Once the compatibility of the new vertical dimension had been confirmed, interim fixed restoration and the permanent reconstruction was initiated. This case reports that a satisfactory clinical result was achieved by restoring the vertical dimension with an improvement in esthetics and function.

Anterior tooth wear and retention type until 5 years after orthodontic treatment

Objectives. To study occlusal wear of anterior teeth in orthodontic patients retained with different retainers until 5 years post-treatment, and to investigate whether type of retention influences occlusal wear. Material and methods. Orthodontic patients (n=222), aged 15 years maximally at the start of treatment, were followed until 5 years post-treatment. In the maxilla, a retainer bonded on all six teeth or a removable retainer was used; in the mandible, a lingual retainer was bonded on all anterior teeth or on canines only. Dental casts were analyzed before treatment (T0), after treatment (T1), and 5 years post-treatment (T5). Incisal and canine wear were scored by applying a grading scale. Intercanine width, overjet, and overbite were measured with an electronic caliper. Statistics used were: Paired samples t-test for differences over time; Pearson correlation coefficients for associations between wear and retention type; and backward linear regression for influence of retention type on wear. Results. There was an increase in wear during all time periods and for all teeth. From T0 to T5 an increase in maxillary intercanine width and maxillary retention had an effect on changes in canine wear. Incisal wear was associated with an increase in upper intercanine width (T1–T5). For both arches, an increase in maxillary intercanine width during treatment was associated with less progression of canine and incisal wear, but the explained variance was low, 13.4% and 19.3%, respectively. Conclusions. Retention type and, occasionally, an increase in intercanine width influence anterior teeth wear post-treatment. However, the clinical significance and impact of the examined retention methods on occlusal wear are small.

Techniques for Restoring Worn Anterior Teeth with Direct Composite Resin

Toothwear is increasing in prevalence. Traditional treatment methods for moderate or advanced toothwear, such as indirect restorations and crown lengthening surgery, are invasive and destructive of remaining tissues. The 'Dahl technique' has been used to obtain space for anterior restorations and has been modified such that direct composite restorations are placed at increased occlusal vertical dimension. These restorations have proved durable and aesthetic, protect tooth structure and posterior occlusal contact is predictably re-established. The authors describe and compare two techniques using composite resin to treat localized anterior toothwear in a general practice setting. Toothwear is a significant clinical problem and general dental practitioners and specialists alike must be familiar with the available conservative treatment options.

Anterior tooth wear and temporomandibular disorders

Anterior tooth wear and temporomandibular disorders

Effect of dental wear, stabilization appliance and anterior tooth reconstruction on mandibular movements during speech

This study described changes in mandibular movements during pronunciation of /m/ and /s/ sounds in Portuguese, in patients presenting dental wear before and after appliance insertion and tooth reconstruction. Subjects were divided into a control group of dentate patients and an experimental group of patients with incisal tooth wear due to bruxism. A magnetic jaw tracking device measured the jaw opening, and translations to left and right sides of the mandible during pronunciation of phonemes. Evaluations were carried out 1 week and immediately before appliance insertion; 24 h, 7, 30 and 60 days after appliance insertion; and 1 week and 1 month after tooth reconstruction. Data were submitted to two-way ANOVA, Mann-Whitney and Friedman tests (p<0.05). Jaw opening was different (p<0.05) for both sounds in all periods. The anteroposterior amplitude for /s/ showed differences immediately before and 1 month after appliance insertion (p<0.05). Lateral amplitude for the right side showed differences between groups after appliance insertion for /s/, and 1 and 2 months after appliance insertion for the /m/ (p<0.05). Volunteers with anterior tooth wear had a wider opening movement, and the movements during speech of /m/ and /s/ sounds were not changed after appliance insertion and reconstruction of teeth.

Association between anterior tooth wear and temporomandibular disorder pain in a German population

Bruxism is purported to be a risk factor for temporomandibular disorder (TMD) pain, but the association requires clarification. The purpose of this study was to investigate the relation between anterior tooth wear as an indicator for bruxism and the presence of TMD pain. Study subjects included 646 participants (age range 35 to 44 years) of a national oral health survey in Germany. Anterior tooth wear was registered for each anterior tooth with a 4-point scale (none, mild, moderate, and severe wear). Temporomandibular disorder was defined as self-reported pain in the face, jaw muscles, and/or temporomandibular joint (TMJ) during the last month, according to either the German version of the Research Diagnostic Criteria for Temporomandibular Disorders or the response to a question about pain in the masticatory muscles or the TMJ according to the Helkimo-Index. A multiple logistic regression analysis, controlling for the effects of age and gender, investigated the linear relationship between increased tooth wear and the risk of TMD pain. After adjusting for age and gender, an odds ratio of 1.11 (95% confidence interval: 0.7-1.8) indicated that the risk of TMD pain increased an estimated 11% per unit increase of tooth wear. There was no statistically significant or clinically relevant relationship between a linear increase of tooth wear and risk of TMD pain. Anterior tooth wear was not associated with self-reported TMD pain in 35- to 44-year-old subjects. Using anterior tooth wear as an indicator for long-term bruxing behavior, a clinically relevant dose-response relationship between this type of bruxism and TMD pain does not appear to exist.

Treatment of localized anterior tooth wear with a glass-fiber–reinforced composite resin: A clinical report

Developments in adhesive dentistry have provided the dental profession with new restorative materials and technology to restore esthetics and function to the worn anterior dentition. This clinical report describes treatment of localized anterior tooth wear with fiber-reinforced composite resin restorations as an alternative treatment method.

Tooth wear in maxillary anterior teeth from 14 to 23 years of age

Using a planimetric method, the size of horizontal wear facets on maxillary anterior teeth was studied longitudinally in the permanent dentition of 35 subjects at ages 14, 18, and 23 years. The study subjects had not previously undergone any orthodontic treatment and had Class I occlusion. We studied the association between the amount of wear and reported parafunctions and maximal bite force. Total wear areas in age groups 14, 18, and 23 years were 29.5 mm2 (SD 11.4), 39.1 mm2 (SD 12.7), and 45.0 mm2 (SD 13.0), respectively. The total wear area increased significantly both from 14 to 18 years of age and from 18 to 23 years of age (p<0.0001). Between 18 and 23 years of age, the maxillary canines showed strongest wear, although the central incisors had largest wear facets. It can be concluded that wear of permanent anterior teeth is a continuous phenomenon in adolescence and young adulthood.

The Dahl Concept: past, present and future

The Dahl appliance was described nearly 30 years ago. This removable metal bite platform was used to create inter-occlusal space, in a localised part of the mouth, to facilitate the placement of restorations on worn anterior teeth. The Dahl concept is traditionally associated with the management of worn teeth. However, the same principles can be successfully and safely applied to a variety of clinical situations. This has simplified the management of historically complex problems. The advantages are the preservation of tooth tissue and the long-term benefits that brings. This paper reviews the literature related to the Dahl concept and how the concept has developed. There is a discussion regarding possible future applications and research.

Reviewing the Concept of Dahl

Toothwear may have a multifactorial aetiology but is often localized to the upper anterior teeth. This is normally accompanied by a loss of interocclusal space. This paper aims to outline the management of localized anterior toothwear. It discusses several options available to create space for anterior restoration, with particular reference to the use of the 'Dahl' technique. Dahl described a non-invasive technique to create increased interocclusal space. The increased space eliminates the need for further occlusal reduction during crown preparation which is ideal in the worn dentition. This paper illustrates and describes the clinical applications of Dahl's original technique.

Prediction of demand for treatment of temporomandibular disorders based on a 20-year follow-up study.

The purpose was to test the hypothesis that signs and symptoms characteristic of temporomandibular disorders (TMD) at age 15 would predict demand for treatment during a 20-year follow-up period. Of originally 135 examined 15-year-old subjects, 103 completed a questionnaire and 84 were examined clinically at the 10-year follow-up (at age 25). After 20 years (at age 35), 114 completed a questionnaire and 100 were also examined clinically. During the 20-year follow-up period, 21 subjects received some kind of treatment of TMD. At baseline (age 15), the treated group reported tooth grinding at night more often than the non-treated group (P = 0.0042). At the 10-year follow-up (at age 25), the treated group reported more symptoms of TMD and oral parafunctions than the non-treated group. Among the clinical registrations, there was only one significant difference between the groups: anterior tooth wear was more extensive in the treated group. At the 20-year follow-up (at age 35), the treated group reported significantly more symptoms of TMD and oral parafunctions than the non-treated group. The clinical dysfunction index was also higher in the treated group. Logistic regression revealed tooth grinding at night as a significant predictor of received treatment of TMD. However, the positive predictive value was low whereas the negative predictive value was high (90%). The findings indicate that nocturnal tooth grinding is related to demand for treatment of TMD.

A Technique for Simple and Aesthetic Treatment of Anterior Toothwear

This article describes a technique for treating anterior toothwear. The technique allows the placement of direct composite on the palatal surface of upper anterior teeth in an efficient and accurate manner. The advantages of an indirect wax-up technique and a direct intra-oral approach are combined to give an aesthetic and conservative result.

Rates of anterior tooth wear in Middle Pleistocene hominins from Sima de los Huesos (Sierra de Atapuerca, Spain).

This study presents quantitative data on the rates of anterior tooth wear in a Pleistocene human population. The data were obtained for the hominin sample of the Sima de los Huesos site in Atapuerca, Spain. The fossil record belongs to a minimum of 28 individuals of the same biological population, assigned to the species Homo heidelbergensis. We have estimated the original and the preserved crown height of the mandibular incisors (I1 and I2) of 11 individuals, whose age at death can be ascertained from the mineralization stage and tooth eruption. Results provide a range of 0.276-0.348 and 0.288-0.360 mm per year for the mean wear rate of the mandibular I1 and I2, respectively, in individuals approximately 16-18 years old. These data suggest that incisors' crowns would be totally worn out toward the fifth decade of life. Thus, we expect the life expectancy of this population to be seriously limited. These data, which could be contrasted with results obtained on hominins at other sites, could be of interest for estimating the death age of adult individuals.

Predictors of bruxism, other oral parafunctions, and tooth wear over a 20-year follow-up period: Gunnar E. Carlsson, Inger Egermark, Tomas Magnusson. J Orofac Pain 2003;17-50-7

Aims To analyze predictors of bruxism, other oral parafunctions, and tooth wear in a group of subjects who had been examined 20 years earlier. Methods Originally, 402 randomly selected 7-, 11-, and 15-year-old subjects were examined clinically and by means of a questionnaire. Twenty years after the first examination, 94% of the original group could be traced, and 320 (85%) completed and returned the questionnaire. Of the oldest group, 100 (81%) also underwent a clinical examination focusing on occlusal factors and function and dysfunction of the masticatory system. For analyses of predictors of some oral parafunctions and tooth wear registered at the 20-year follow-up, logistic regression was used with recordings at the first examination as independent variables. Results Subjective reports in childhood of bruxism (defined as tooth clenching during daytime and/or tooth grinding at night), clenching only, grinding at night only, nail biting, and/or other parafunctions were predictors of the same oral parafunctions 20 years later. There were different predictors of the 2 components of bruxism, daytime tooth clenching and tooth grinding at night. Postnormal occlusion (Angle Class II malocclusion) and tooth wear in childhood predicted increased tooth wear in adulthood. Subjects with nonworking-side interference had less anterior tooth wear than those without such interference. Conclusion Oral parafunctions in childhood may be a persistent trait in many subjects. Postnormal occlusion and tooth wear in childhood predicted increased anterior tooth wear 20 years later, whereas nonworking-side interference reduced the risk for such wear in 35-year-old subjects.

Performance of resin-based composite restorations to manage anterior tooth wear

Objectives To examine the clinical performance of resin-based composite restorations placed at an increased vertical dimension when used to manage localised anterior tooth wear. Design A retrospective analysis of cases treated at a single centre. Setting UK Hospital setting in year 2000. Subjects and Methods Two hundred and twenty five restorations placed in 31 subjects were included. Assessment was made following examination of study casts and projected slides. Modified United States Public Health Services criteria were used and data analysed using the software Statistical Programme for Social Sciences (SPSS). Survival analysis was carried out at two levels, major failure only and all types of failure. Kaplan-Meier survival plots were produced against different variables and modes of failure were also noted. Results Major failure requiring replacement of the restoration was uncommon within the first five years. Minor failure requiring repair or refinishing presented mainly as wear, marginal discolouration or marginal fracture. Median survival was 4 years 9 months when all types of failure were considered. The restorations have good appearance and are well tolerated. Conclusion Placement of resin-based composite restorations at an increased vertical dimension to treat localised anterior tooth wear, has good short to medium term survival. The technique is conservative and relatively easy to maintain.

The survival and clinical performance of resin-based composite restorations used to treat localised anterior tooth wear.

To examine the clinical performance of resin-based composite restorations placed at an increased vertical dimension when used to manage localised anterior tooth wear. A retrospective analysis of cases treated at a single centre. UK Hospital setting in the year 2000. Two hundred and twenty five restorations placed in 31 subjects were included. Assessment was made following examination of study casts and projected slides. Modified United States Public Health Services criteria were used and data analysed using the software Statistical Programme for Social Sciences (SPSS). Survival analysis was carried out at two levels, major failure only and all types of failure. Kaplan-Meier survival plots were produced against different variables and modes of failure were also noted. Major failure requiring replacement of the restoration was uncommon within the first five years. Minor failure requiring repair or refinishing presented mainly as wear, marginal discolouration or marginal fracture. Median survival was 4 years 9 months when all types of failure were considered. The restorations have good appearance and are well tolerated. Placement of resin-based composite restorations at an increased vertical dimension to treat localised anterior tooth wear, has good short to medium term survival. The technique is conservative and relatively easy to maintain.