The evolution of tooth wear indices

The prevalence and risk indicators of tooth wear in 12- and 15-year-old adolescents in Central China

BACKGROUND

Tooth wear has been investigated in numerous countries, and the prevalence has varied. However, the data on tooth wear in China are scarce. The aim of this study was to describe the prevalence of tooth wear and to investigate the relative indicators associated with tooth wear in 12- and 15-year-old adolescents in Wuhan City, Hubei Province, Central China.

METHODS

A cross-sectional descriptive study was undertaken among 720 adolescents in Hubei Province, Central China. The age groups in this study were 12- and 15-year-old, and each group consisted of 360 participants in which females and males represented 50 % each. A modified version of the Basic Erosive Wear Examination (BEWE) tooth wear index was used for the buccal, cervical, occlusal/incisal and lingual surfaces of all of the teeth in the 720 adolescents. All of the participants were asked to answer a questionnaire consisting of questions about their current and historical dietary habits and oral hygiene.

RESULTS

The prevalence of tooth wear was 18.6 and 89.4 % in 12- and 15-year-old adolescents, respectively. The prevalence rates of dentin exposure were 1.9 and 5.6 %, respectively. A significantly higher prevalence of tooth wear and dentin exposure in 15-year-old adolescents was found than in 12-year-old adolescents (p < 0.001 and p = 0.011). Several factors such as drinking soft drinks and fruit juices immediately after sports, taking aspirin, reflux, unilateral chewing, tooth brushing once daily or less often, duration of brushing less than 2 min and swimming in the summer were found to be associated with tooth wear.

CONCLUSIONS

Tooth wear in 12- and 15-year-old adolescents in Central China is a significant problem and should receive greater attention. The prevalence of tooth wear increases with age and associated with socio-behavioral risk factors.

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.

3D Simulation Modeling of the Tooth Wear Process

Severe tooth wear is the most common non-caries dental disease, and it can seriously affect oral health. Studying the tooth wear process is time-consuming and difficult, and technological tools are frequently lacking. This paper presents a novel method of digital simulation modeling that represents a new way to study tooth wear. First, a feature extraction algorithm is used to obtain anatomical feature points of the tooth without attrition. Second, after the alignment of non-attrition areas, the initial homogeneous surface is generated by means of the RBF (Radial Basic Function) implicit surface and then deformed to the final homogeneous by the contraction and bounding algorithm. Finally, the method of bilinear interpolation based on Laplacian coordinates between tooth with attrition and without attrition is used to inversely reconstruct the sequence of changes of the 3D tooth morphology during gradual tooth wear process. This method can also be used to generate a process simulation of nonlinear tooth wear by means of fitting an attrition curve to the statistical data of attrition index in a certain region. The effectiveness and efficiency of the attrition simulation algorithm are verified through experimental simulation.

The relationship between consumption of beverages and tooth wear among adults in the United States

OBJECTIVES

To investigate the prevalence and severity of tooth wear (TW) and its relationship with consumption of beverages among adults in the United States.

METHODS

The National Health and Nutrition Examinations Survey data for 2003-2004 was analyzed. TW was defined as "wear on at least one surface of at least one examined tooth." Drink/juice consumption was ascertained via a Food Frequency Questionnaire processed with Diet*Calc software to obtain the average daily consumption frequency for all queried drinks and juice categories including milk. Survey-weighted descriptive and multivariable analyses with interaction terms were performed.

RESULTS

Our study sample consisted of 3,773 adults (aged 20 and above). Eighty percent of the subjects had evidence of TW, and soft drinks were the most consumed beverage. Significant interactions between the effects of age, gender, and race/ethnicity on TW were found (P < 0.001). After adjustment for demographic factors, consumption of fruit drinks was found to be significantly associated with the severity [odds ratio (OR) = 1.32 and 1.42], but not prevalence of TW. However, this trend was reversed for grape juice consumption (OR = 0.34, 0.41).

CONCLUSIONS

This study demonstrates that a substantial proportion of adults had evidence of TW, which was affected by demographic factors in a complex way. Fruit drinks consumption in adults was associated with the severity of TW, but not with the prevalence of TW after adjusting for demographics. These findings are important for the development of appropriate treatment guidelines, public policy, and programs aimed at reducing TW in adults.

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.

Dental erosion: a widespread condition nowadays? A cross-sectional study among a group of adolescents in Norway

OBJECTIVE

This study aimed to investigate the prevalence, distribution and severity of erosive wear in a group of 16-18-year-olds in the western part of Norway. A second aim was to describe possible associations between caries experience, socioeconomic background and origin of birth.

MATERIALS AND METHODS

Adolescents (n = 795) attending recall examinations at Public Dental Service (PDS) clinics were also examined for dental erosive wear on index surfaces, using the Visual Erosion Dental Examination scoring system (VEDE).

RESULTS

In total, 795 individuals were examined. Dental erosive wear was diagnosed in 59% of the population (44% erosive wear in enamel only, 14% combination of enamel and dentine lesions, 1% erosive wear in dentine only). The palatal surfaces of upper central incisors and occlusal surfaces of first lower molars were affected the most (33% and 48% of all surfaces, respectively). Cuppings on molars were registered in 66% of the individuals with erosive wear. Erosive wear was significantly more prevalent among men (63%) than women (55%) (p = 0.018).

CONCLUSIONS

There were no significant associations between dental erosive wear and caries experience, socioeconomic background or origin of birth.

Predicting tooth surface loss using genetic algorithms-optimized artificial neural networks

Our aim was to predict tooth surface loss in individuals without the need to conduct clinical examinations. Artificial neural networks (ANNs) were used to construct a mathematical model. Input data consisted of age, smoker status, type of tooth brush, brushing, and consumption of pickled food, fizzy drinks, orange, apple, lemon, and dried seeds. Output data were the sum of tooth surface loss scores for selected teeth. The optimized constructed ANN consisted of 2-layer network with 15 neurons in the first layer and one neuron in the second layer. The data of 46 subjects were used to build the model, while the data of 15 subjects were used to test the model. Accepting an error of ±5 scores for all chosen teeth, the accuracy of the network becomes more than 80%. In conclusion, this study shows that modeling tooth surface loss using ANNs is possible and can be achieved with a high degree of accuracy.

An investigation of risk factors associated with tooth surface loss: a pilot study

Few prospective studies have investigated risk factors associated with severe tooth surface loss. This case-control study assessed the possible association between medical history, diet, psychological profile and salivary pH and flow [Delongis 1982, Johansson 1993] with the incidence of severe tooth surface loss. A total of 80 subjects (40 cases and 40 age- and gender-matched controls) aged 25-85 years were recruited. Cases were subjects with severe tooth surface loss, and controls with mild tooth surface loss. Conditional logistic regression analysis estimated the odds of severe tooth surface loss to be 15·4 times higher for those with cardiovascular disease and 16 times for gastrointestinal disturbances. Most domains of the psychological profile were associated with elevated risk of severe tooth surface loss, particularly the effects of finance and health. Recreational drug use and prescription medications were also associated with severe tooth surface loss. There was no association between salivary flow and severe tooth surface loss. Although not statistically significant, the pH was slightly lower in the severe tooth surface loss group.

Occlusal tooth wear in the general population of Germany: effects of age, sex, and location of teeth

STATEMENT OF PROBLEM

Tooth wear is an increasing problem in a society where people are living longer.

PURPOSE

The purpose of this study was to assess the effect of age, sex, and location of teeth on the severity of tooth wear and to determine the prevalence of dentin exposure in the general population of Germany.

MATERIAL AND METHODS

Tooth wear was measured in casts of both jaws of 836 persons with a 6-point (0-5) ordinal rating scale. Linear random-intercept regression models with the covariates of age, sex, jaw, and tooth group (with the participant as a grouping variable) were computed to determine the association of these covariates with tooth wear of a single tooth.

RESULTS

The mean tooth wear score across all age groups, both sexes, and all teeth was 2.9 (standard deviation, 0.8), and the prevalence of teeth with exposed dentin was 23.4%. The participants' age was correlated with the mean tooth wear scores (r=0.51). The tooth wear level among women was on average 0.15 units lower than among men, and tooth wear was on average 0.59 units higher for anterior teeth than for posterior teeth.

CONCLUSIONS

Increased tooth wear in anterior teeth may be due to the initially predominant guidance by anterior teeth, with age-related linear progress in tooth wear. Occlusal tooth wear scores and dentin exposure increase with age.

Association between Periodontal Status, Oral Hygiene Status and Tooth Wear among Adult Male Population in Benin City, Nigeria

Background:

The association between periodontal status, oral hygiene status and severity of tooth wear lesion varies from community to community and also from occupation to occupation.

Aim:

To determine the association between periodontal status, oral hygiene status and tooth wear among the adult male population in Benin City, Nigeria.

Subjects and Methods:

This study was conducted among 65 male drivers, aged 25-64 years, with a mean age of 48.6 (9.1) years in an organized private motor park in Benin City between November 2011 and January 2012. The data collected through interview and clinical oral examination were age, educational status, driving experience, oral hygiene status, periodontal status and severity of tooth wear.

Results:

In this study, 13.8% (9/65) and 1.5% (1/65) of the participants had 4-5 mm and ≥6 mm periodontal pockets, respectively. A total of 15.4% (10/65) of the participants had poor oral hygiene status and 58.5% (38/65) of the participants had tooth wear lesion, with 15.8% (9/65) being severe tooth wear lesions (score 3). Participants with poorer oral hygiene and more severe tooth wear lesions significantly exhibited poorer periodontal status. There also existed a significant association between oral hygiene status and the severity of tooth wear lesion among the participants in this study.

Conclusion:

Data from this study revealed a statistically significant association between periodontal status, oral hygiene status and severity of tooth wear lesion among the participants.

Evaluation of the basic erosive wear examination (BEWE) for use in general dental practice

OBJECTIVE

The basic erosive wear examination (BEWE) is a relatively new index proposed for the screening and recording of tooth wear in adults. The aim of this study was to test the validity and reliability of the BEWE.

DESIGN

Cross sectional study of a sample of 164 adult patients.

SETTING

General dental practice in East Lancashire, UK in 2010.

SUBJECTS

Patients attending for routine examination or treatment.

MAIN OUTCOME MEASURES

By screening patients with the BEWE and comparing the results to the established tooth wear index (TWI) the sensitivity and specificity of the BEWE was established.Results The BEWE predicted moderate to severe wear (BEWE grade 3) with a sensitivity of 48.6% and a specificity of 96.1%, and predicted severe wear with a sensitivity of 90.9% and a specificity of 91.5% (also BEWE score 3). Inter- and intra-examiner reliability for the BEWE were both moderate (κ(w) = 0.43 and 0.57 respectively).

CONCLUSION(S)

BEWE scores show a similar distribution to TWI scores and the examination is an effective screening test for severe tooth wear. The moderate levels of examiner reliability suggests the BEWE scores should be interpreted with some caution.

Gastroesophageal reflux, dental erosion, and halitosis in epidemiological surveys: a systematic review

In published studies, it has been suggested that dental wear is associated with gastroesophageal reflux disease (GERD). This systematic review was carried out to evaluate the association of GERD, dental erosion, and halitosis and to compare the indices adopted in epidemiological surveys. The Medline database (until October, 2011) was searched systematically to identify studies evaluating the prevalence of oral alterations, such as dental erosion and halitosis, in patients with GERD symptoms. Two reviewers analyzed all reports and the selected studies were evaluated according to the quality of evidence, using the validated Newcastle-Ottawa Quality Assessment Scale. Full-text copies of a total of 32 publications were obtained in duplicate. Sixteen publications were identified among the citations in the Bibliographic lists of studies that fulfilled the exclusion/inclusion criteria and quality of evidence. The relationship between dental erosion and GERD patients was significant in only seven studies. According to three studies, halitosis could be one of several extraesophageal symptoms or manifestations in GERD patients. In one study, it was found that the mucosa of GERD patients was significantly more acidic in comparison with that of the control group. This systematic review showed that there is a relationship between GERD and oral diseases (dental erosion and halitosis). The epidemiological surveys used different indices to analyze GERD and dental erosion. Further research could investigate the best method for assessing the two diseases.

Tooth surface loss and associated risk factors in northern saudi arabia

Aim. To evaluate tooth surface loss (TSL) severity and associated risk factors in a representative sample of Saudi adults. Materials and Methods. Four hundred TSL patients (200 females and 200 males) participated in this study. Each patient completed a comprehensive questionnaire interview (using a modified Tooth wear Assessment Questionnaire) and then examined for the severity of TSL (using ordinal scale). Results. Seventy-five percent of participants demonstrated attrition, 90% had erosion, 15% had abrasion, and 95% had more than one type of TSL. The most common risk factors were consumption of acidic food/drinks (78%), parafunctional habits (70%), and unilateral chewing (50%). 77% of participants demonstrated grade 2 TSL. Males demonstrated greater TSL severity (P ≤ 0.05). Age, systemic disease, number of remaining teeth, acidic food/drinks, bruxism/parafunction, biting objects, facial pain/tenderness, sour taste, exposure to dust, unilateral chewing, using dental abrasives, and brushing frequency/technique had significant relationship with TSL severity (P ≤ 0.05). Conclusions. TSL has a multifactorial aetiology. Parafunction, gastrointestinal problems, and diet were the most common aetiological factors reflecting changes to stressful modern life-styles, eating/drinking habits, and behaviours. Gender didn't influence the aetiology of TSL; however males demonstrated more TSL severity. Patients' age had significant correlation to TSL severity.

Severe tooth wear in Prader-Willi syndrome. A case-control study

BACKGROUND

Prader-Willi syndrome (PWS) is a rare complex multsystemic genetic disorder characterized by severe neonatal hypotonia, endocrine disturbances, hyperphagia and obesity, mild mental retardation, learning disabilities, facial dysmorphology and oral abnormalities. The purpose of the present study was to explore the prevalence of tooth wear and possible risk factors in individuals with Prader-Willi syndrome.

METHODS

Forty-nine individuals (6-40 years) with PWS and an age- and sex-matched control group were included. Tooth wear was evaluated from dental casts and intraoral photographs and rated by four examiners using the Visual Erosion Dental Examination (VEDE) scoring system and the individual tooth wear index IA. In accordance with the VEDE scoring system, tooth wear was also evaluated clinically. Whole saliva was collected.

RESULTS

Mean VEDE score was 1.70 ± 1.44 in the PWS group and 0.46 ± 0.36 in the control group (p < 0.001). Median IA was 7.50 (2.60-30.70) in the PWS group and 2.60 (0.90-4.70) among controls (p < 0.001). In the PWS group tooth wear correlated significantly with age (VEDE; r = 0.79, p < 0.001, IA; r = 0.82, p < 0.001) and saliva secretion (VEDE; r = 0.46, p = 0.001, IA; r = 0.43, p = 0.002). Tooth grinding was also associated with tooth wear in the PWS group, as indicated by the mean VEDE 2.67 ± 1.62 in grinders and 1.14 ± 0.97 in non-grinders (p = 0.001) and median IA values 25.70 (5.48-68.55) in grinders and 5.70 (1.60-9.10) in non-grinders (p = 0.003). Multivariate linear regression analysis was performed with tooth wear as the dependent variable and PWS (yes/no), age, tooth grinding and saliva secretion as independent variables. PWS (yes/no), age and tooth grinding retained a significant association with tooth wear, VEDE (p < 0.001) and log IA (p < 0.001). The only factor significantly associated with tooth wear in the control group was age.

CONCLUSIONS

Our study provides evidence that tooth wear, in terms of both erosion and attrition, is a severe problem in Prader-Willi syndrome. There is therefore considerable need for prosthodontic rehabilitation in young adults with PWS.

Prevalence and associated factors of dental erosion in children and adolescents of a private dental practice

BaCKGROUND. The prevalence of dental erosion seems to be rising in young populations, particularly among individuals of higher socioeconomic status. AIM. To assess the prevalence and associated factors of dental erosion in children and adolescents of a private dental practice. DESIGN. A total of 232 participants, aged 2-20 years, were examined. Dietary habits, oral hygiene, and medical data were collected from dental records. Logistic regression analyses were conducted. RESULTS. Dental erosion prevalence was of 25.43% and was highest on the occlusal surfaces (76%). Associated factors were: frequent consumption of soft drinks (OR = 2.33; 95% CI = 1.01-5.38) and candies (OR = 3.23; 95% CI = 1.25-8.32); and interaction between these two factors (OR = 3.95; 95% CI = 1.60-9.75). On anterior teeth, associated factors were: frequent consumption of fruits (OR = 2.53; 95% CI = 1.09-5.91); and age (OR = 1.07 95% CI = 1.01-1.14). Milk consumption was associated with a lower prevalence of dental erosion (OR = 0.40; 95% CI = 0.17-0.94). CONCLUSIONS.  A relatively high prevalence of erosion was found in association with frequent intake of soft drinks, candies, and fruits. The consumption of milk seemed to protect against dental erosion on anterior teeth.

Orthodontic anomalies and malocclusions in Late Antique and Early Mediaeval period in Croatia

OBJECTIVE

Malocclusions are relative infrequently analysed in bioarchaeological investigations and if investigated the samples are very small. This research provides analysis of orthodontic anomalies of even 1118 individuals from the Late Antique (LA) and Early Mediaeval (EM) period. Aims were to describe the prevalence of orthodontic anomalies in this historical period and to analyse which orthodontic anomalies are best suitable for bioarchaeological investigations.

METHODS

1118 skulls were examined for anomalies of tooth number, tooth displacement (rotation, malposition, diastema and crowding) as well as for malocclusions.

RESULTS

The prevalence of hypodontia in the LA was 41.02% and 30.61% in the EM sample. Tooth displacement was noticed in 15.63% individuals from the LA and in 12.42% individuals from EM. About 26% of the LA sample and 7.19% of the EM sample were affected with tooth crowding and the difference was statistically significant.

CONCLUSION

Orthodontic anomalies affecting only one tooth or group of teeth are more suitable for examination in bioarchaeological investigations than orthodontic features requiring presence of both jaws and all or almost all teeth. Clinical investigation protocols and methodology should be adopted for bioarchaeological researches and international standards and recommendations should be established for this kind of investigation on skeletal remains.

Tooth wear and wear investigations in dentistry

Tooth wear has been recognised as a major problem in dentistry. Epidemiological studies have reported an increasing prevalence of tooth wear and general dental practitioners see a greater number of patients seeking treatment with worn dentition. Although the dental literature contains numerous publications related to management and rehabilitation of tooth wear of varying aetiologies, our understanding of the aetiology and pathogenesis of tooth wear is still limited. The wear behaviour of dental biomaterials has also been extensively researched to improve our understanding of the underlying mechanisms and for the development of restorative materials with good wear resistance. The complex nature of tooth wear indicates challenges for conducting in vitro and in vivo wear investigations and a clear correlation between in vitro and in vivo data has not been established. The objective was to critically review the peer reviewed English-language literature pertaining to prevalence and aetiology of tooth wear and wear investigations in dentistry identified through a Medline search engine combined with hand-searching of the relevant literature, covering the period between 1960 and 2011.

Tooth wear in the deciduous dentition of 5-7-year-old children: risk factors

This study was conducted to investigate the distribution and severity of tooth wear in deciduous dentition and its relationship with possible risk factors. A stratified cluster sample of 243 5-7-year-old children was examined using the tooth wear index of Smith and Knight, and their exposure to intrinsic and extrinsic risk factors was retrospectively investigated through a structured questionnaire. The severity of wear was quantitatively estimated by the number of surfaces with affected dentine and by the cumulative score of the sextants, based on the Basic Erosive Wear Examination scoring system. Only 1.6% of the children were tooth wear free, whereas 45.6% had moderate to severe wear involving dentine. Maxillary canines were the most affected teeth (83.2%), and occlusal/incisal the most affected surfaces (52.7%). The likelihood of tooth wear involving dentine was greater in boys than girls (OR = 1.72), in immigrants than in Greeks (OR = 1.93), and in 6- and 7-year olds than in 5-year olds (OR = 2.78 to 2.93). After adjustment for age, gender, and nationality, exposure to several dietary factors and especially to soft drinks was found to significantly affect the prevalence (OR = 1.27) and the severity of tooth wear. Every additional serving/week of consumption of soft drinks increases the number of surfaces with dentine affected by 0.03 per year (p < 0.05) and the cumulative score of sextants by 0.04 (p < 0.05). The cluster of children with the higher prevalence and severity of tooth wear had an average exposure to soft drinks of 10 servings/week for a duration of 4 years. The cumulative score of sextants was better predicted by the assessed risk factors, in comparison with the number of surfaces with affected dentine. Tooth wear is a common condition in children, related both to the physiological process of aging of dentition and to the erosive effect of dietary factors. Strategies to reduce the intake of soft drinks in children are expected to have multiple benefits preventing tooth wear in childhood and in later life, as well as many other general and oral health diseases.

Morphological heterogeneity of oral salivary gland carcinomas: a clinicopathologic study of 41 cases with long term follow-up emphasizing the overlapping spectrum of adenoid cystic carcinoma and polymorphous low-grade adenocarcinoma

We analyzed 41 oral salivary gland carcinomas from consecutive 290 salivary gland carcinoma database (14%) with emphasis on the histological spectrum and clinical outcome of adenoid cystic carcinoma (ACC) and polymorphous low-grade adenocarcinoma (PLGA). The cohort included 14 ACCs, 14 mucoepidermoid carcinomas (MECs), 8 PLGAs, 3 adenocarcinomas, not otherwise specified and 2 acinic cell carcinomas. Mean age was 48, 58 and 61 yrs for ACC, MEC and PLGA, respectively. Eight patients (19.5%) died of tumor at a mean interval of 66.5 months. ACC and PLGA showed similar mean age, gender distribution, predominant palatal localization, nodal metastasis, perineural invasion and MIB-1 index. However, ACC tended to show higher tumor stage and residual tumor (R1/R2) more frequently than PLGA, but this was statistically not significant. ACC and PLGA showed overlapping architectural patterns. However, ACCs displayed well organized basal-luminal differentiation, highlighted by CK5/CK7 immunostaining. In contrast, PLGA showed a disorganized histological and immunohistological pattern. C-Kit expression (CD117) was common in ACC, generally mirroring that of CK7 and virtually lacking in PLGA. Kaplan-Meier analysis demonstrated a similar clinical course for ACC and PLGA with 5 years survivals of 87% and 80%, respectively. Fluorescence in situ hybridization (FISH) performed on all 290 salivary carcinomas confirmed the specificity of the translocation t (11; 19) for MEC and its absence in all other carcinomas including ACC and PLGA. Our results emphasize the diversity of oral salivary gland carcinomas and the overlapping clinicopathological features of ACC and PLGA.

Risk indicators for erosive tooth wear in Brazilian preschool children

The aim of this study was to assess the prevalence and risk indicators for erosive tooth wear (ETW) in Brazilian preschool children. A total of 967 children aged 3-4 years were examined. ETW was assessed using a modified version of the index recommended by O'Brien [London, Her Majesty's Stationary Office, 1994]. The 16 examiners were trained and calibrated. Hierarchical logistic regression was applied to investigate the association between ETW and socio-economic, environmental, nutritional and behavioural factors, as well as factors related to the child's characteristics. ETW was present in 51.6% of children. Most lesions were confined to enamel (93.9%) and involved over two thirds of the tooth surface's area (82%). There were no significant associations between ETW and socio-economic, environmental and nutritional variables. ETW was significantly associated with soft drink intake twice or 3 or more times a day (p = 0.043 and 0.023, respectively), frequent reported gastro-oesophageal reflux (p = 0.005) and age (p = 0.003). In conclusion, there was a high prevalence of ETW in the preschool children examined, and the risk indicators were frequent consumption of soft drinks, reported gastro-oesophageal reflux and age.

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 (T(0)), after treatment (T(1)), and 5 years post-treatment (T(5)). 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 T(0) to T(5) 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 (T(1)-T(5)). 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.

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.