Association between self-reported bruxism activity and occurrence of dental attrition, abfraction, and occlusal pits on natural teeth

Non-Instrumental and Instrumental Tools Validity in Bruxism Diagnostics

Background/Objectives: The study aimed to validate the diagnostic system proposed by the Standardized Tool for the Assessment of Bruxism (STAB) by correlating the results obtained based on questionnaire and non-instrumental and instrumental tools. Methods: The study had three stages (questionnaire, clinical examination, and electromyographic study). The subjects completed a questionnaire and clinical exam. Positive signs of bruxism included oral mucosal signs and the presence of dental wear according to the BEWE index. In stage three, sEMG was performed after allocating subjects into four groups according to the questionnaire and clinical exam results: sleep bruxism (SB), awake bruxism (AB), sleep and awake bruxism (SB AB), and no bruxism (no B). After the third stage, a new selection was made, and the subjects were divided into four groups, according to sEMG results. Diagnostic accuracy was computed for possible bruxism SB and grinding and clenching sound diagnosis, possible bruxism AB and AB acknowledgment, possible bruxism SB AB, and tooth wear index. Results: For SB, the sensitivity and specificity of the tools were the highest. The non-instrumental questionnaire and clinical assessment identified 67% of SB cases and 89% without SB. For AB, the specificity was higher (84%), while the sensitivity was lower (55%), as almost half of the subjects were not aware of the presence of AB. The tests showed a low sensitivity (15%) but a high specificity (83%) for tooth wear. The absence of tooth wear was frequently associated with the absence of bruxism, while the presence of tooth wear did not necessarily imply the existence of bruxism. Conclusions: Non-instrumental evaluation of bruxism through questionnaires and clinical exams is valuable, especially for SB. Instrumental evaluation through electromyography remains a gold standard for bruxism diagnosis.

Analysis of dental chipping for identifying and diagnosing tooth fracture patterns in osteological series

OBJECTIVE

To develop a specific methodology for identifying dental chipping and determining its temporal occurrence in past populations.

DESIGN

The analysed sample comprised of 2191 human teeth from various Bronze Age on the Iberian Peninsula (Argar culture, 1900-1450 cal BC). Among these, 471 chipped teeth were identified. Chipping was examined using various microscopic techniques (digital three-dimensional, optical, and confocal), focusing on distribution, morphology, position in the tooth, extent of damage, and post-chipping antemortem modifications (PCAM).

RESULTS

The distribution and morphology of the chips enabled the identification chipping mechanism of the chipping, providing valid criteria to distinguish between antemortem and postmortem chipping. Microscopic analyses of the chipping segments-edges, sidewalls, surface, and surrounding area-facilitated determination of the time the chip ocurred (antemortem: recent, less recent, or not recent).

CONCLUSIONS

While experimental studies provide valuable insights into chipping mechanisms, many criteria may not be applicable to past populations because of the presence of PCAM. The lack of PCAM in some Argaric teeth suggests that previous studies may have underestimated the prevalence of chipping in past populations.

Prevalence and predictors of bruxism in two university clinic patient populations with dental implants: A cross-sectional analysis

OBJECTIVE

To analyze the prevalence, predictors, and prosthetic complications of bruxing patients with dental implants in two tertiary clinics in Istanbul, Turkey.

METHODS

Patients with at least one dental implant and with a fixed prosthesis were examined for the evidence of probable bruxism. Factors that could be related to bruxism were analyzed in relation to patient-specific variables. Technical and mechanical complications were investigated.

RESULTS

A total of 1688 patients were analyzed. The overall rate of probable bruxism was 19.72%. Besides self-reported bruxism (p < 0.022), antidepressant use (p < 0.002), frequent headaches (p < 0.014), and observation of linea alba (p < 0.028) were the predictors for probable bruxism. Technical and mechanical complications were frequent in the probable bruxers (p < 0.05).

CONCLUSION

Overall prevalence of bruxism was 19.72%, and bruxism was associated with general and gender-specific predictors.

Association between the severity of possible sleep bruxism and possible awake bruxism and attrition tooth wear facets in children and adolescents

OBJECTIVE

To evaluate the association between the severity of possible sleep bruxism (PSB) and possible awake bruxism (PAB) and attrition tooth wear facets (ATWF) in children/adolescents.

METHODS

Four hundred-thirty-four children/adolescents enrolled in schools in Lavras, Brazil, participated in this cross-sectional study. Caregivers answered a questionnaire about their childrens' PSB. Children/adolescents answered a questionnaire about the occurrence of PAB.

RESULTS

ATWF among individuals without PSB and PAB was lower than those with moderate/severe PSB (p = 0.038) and moderate/severe PAB (p = 0.003). ATWF in anterior teeth was lower among individuals without PSB compared to those with mild (p = 0.015) and moderate/severe PSB (p = 0.032). ATWF in posterior teeth was lower among individuals without PAB compared to those with mild (p = 0.046) and moderate/severe PAB (p = 0.017).

CONCLUSION

The number of attrition tooth wear facets is proportional to the severity of PSB and PAB.

The Role of Occlusal Appliances in Reducing Masseter Electromyographic Activity in Bruxism

Background/Objectives: Bruxism is a masticatory muscle activity, phasic or tonic, with/without teeth contact, that appears in sleep or an awake state. An instrumental technique used to measure the surface electromyographic (sEMG) activity of the masseter muscle is used to diagnose bruxism activity during sleep and while awake. The objective of this study was to compare the variation in bruxism (sleep and awake) indices and masseter activity indices in low sleep bruxism and moderate sleep bruxism before and after wearing an occlusal appliance (OA) for 3 months each night. Methods: A clinical interventional study was designed in which subjects diagnosed with sleep bruxism were randomly selected to be included in the study. After the first sEMG recording, two groups were formed: a low sleep-bruxism group (number of sleep-bruxism events/h between 2 and 4) and a moderate sleep-bruxism group (number of sleep-bruxism events/h equal or higher than 4). All subjects received treatment with a 3D-printed occlusal appliance and wore it each night for 3 months, at which point the second sEMG recording was performed. For each participant of this study, a chart was created that included anamnestic data, clinical data, and sEMG data. The data were statistically analyzed with SPSS, using the Mann-Whitney U and Wilcoxon signed-rank tests. Results: A total of 21 participants were included in the final analysis, 18 women and 3 men, with a mean age of 24.5 ± 2.7 years. The OA lowered all bruxism indices in the whole group, but clusters analysis showed a significant reduction in sleep-bruxism indices in the moderate sleep-bruxism group, while in the low-bruxism group, the sleep and awake indices varied insignificantly, and the number of sleep-bruxism events/h remained constant. Conclusions: The 3D-printed occlusal appliances significantly lowered the sleep-bruxism indices and sleep masseter activity indices recorded with a portable sEMG device in the moderate sleep-bruxism group. The OA lowered the awake-bruxism indices and awake masseter activity indices in the moderate sleep-bruxism group.

Tooth wear and bruxism: A scoping review

OBJECTIVE

This study presents a scoping review to determine the association between tooth wear and bruxism.

DATA

A protocol was developed a priori (Open Science Framework (DOI 10.17605/OSF.IO/CS7JX)). Established scoping review methods were used for screening, data extraction, and synthesis. Risk of bias was assessed using JBI tools. Direct associations between tooth wear and bruxism were assessed.

SOURCES

Embase, SCOPUS, Web of Science, Cochrane, and PubMed were searched.

STUDY SELECTION

Any clinical study containing tooth wear and bruxism assessment done on humans in any language was included. Animal, in-vitro studies and case reports were excluded.

CONCLUSIONS

Thirty publications reporting on the association between tooth wear and bruxism were included. The majority of publications were cross-sectional studies (90%) while only three were longitudinal (10%). Eleven papers assessed definitive bruxism for analysis (instrumental tools), one paper assessed probable bruxism (clinical inspection with self-report) and eighteen assessed possible bruxism (self-report). Of the eleven papers assessing definitive bruxism, eight also reported outcomes of non-instrumental tools. Tooth wear was mostly scored using indexes. Most studies reported no or weak associations between tooth wear and bruxism, except for the studies done on cervical tooth wear. When bruxism assessment was done through self-report, more often an association was found. Studies using multivariate analyses did not find an association between tooth wear and bruxism, except the cervical wear studies. Evidence shows inconclusive results as to whether bruxism and tooth wear are related or not. Therefore, well-designed longitudinal trials are needed to address this gap in the literature.

CLINICAL SIGNIFICANCE

Based on the evidence, dental clinicians should not infer bruxism activity solely on the presence of tooth wear.

Instrumental assessment of sleep bruxism: A systematic review and meta-analysis

This systematic review and meta-analysis (MA) aimed to evaluate the diagnostic validity of portable electromyography (EMG) diagnostic devices compared to the reference standard method polysomnography (PSG) in assessing sleep bruxism. This systematic review was completed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) statement and was registered with PROSPERO prior to the accomplishment of the main search. Ten clinical studies on humans, assessing the diagnostic accuracy of portable instrumental approaches with respect to PSG, were included in the review. Methodological shortcomings were identified by QUADAS-2 quality assessment. The certainty of the evidence analysis was established by different levels of evidence according to the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) framework. A meta-analysis of diagnostic test accuracy was performed with multiple thresholds per study applying a two-stage random effects model, using the thresholds offered by the studies and based on the number of EMG bruxism events per hour presented by the participants. Five studies were included. The MA indicated that portable EMG diagnostic devices showed a very good diagnostic capacity, although a high variability is evident in the studies with some outliers. Very low quality of evidence due to high risk of bias and high heterogeneity among included studies suggests that portable devices have shown high sensitivity and specificity when diagnosing sleep bruxism (SB) compared to polysomnography. The tests performed in the MA found an estimated optimal cut-off point of 7 events/hour of SB with acceptably high sensitivity and specificity for the EMG portable devices.

Noncarious cervical lesions: Response from a 25-year clinical follow-up study

STATEMENT OF PROBLEM

The etiology and diagnosis of noncarious cervical lesions (NCCLs) remain poorly understood.

PURPOSE

The purpose of this clinical study was to examine NCCL progression in an existing group of participants, establish the incidence of new NCCLs in a 25-year follow-up study, and relate them to possible risk factors, including occlusal factors.

MATERIAL AND METHODS

Thirty-three participants who had completed a questionnaire about their habits, diet, and personal information were evaluated in this observational retrospective study. Impressions were made, and casts from 3 time periods (Phase I in 1996, Phase II in 1999, and Phase III in 2021) were scanned to obtain digital casts. The casts were then evaluated in a 3-dimensional analysis software program (Geomagic Control; 3D Systems) to establish digital comparisons between NCCLs and occlusal wear. Furthermore, data from an occlusal analysis device (T-Scan; Tekscan) collected in Phase I was used to analyze occlusal interferences relating to the progression of NCCLs. The statistical analysis applied nonparametric tests, followed by the assessment of the association between NCCLs and risk factors, including occlusal wear, through binary logistic regression (α=.05).

RESULTS

At the end of Phase III, 7 new individuals with NCCLs were detected compared with Phase II. The median percentage progression of NCCLs per participant was 0.0% in Phase I, 7.1% in Phase II, and 35.7% in Phase III (P<.005). Occlusal wear in Phase I was associated with 5.02 times the occurrence of NCCLs in Phase III; occlusal wear in Phase II was associated with 4.73 times the occurrence of NCCLs in Phase III; and occlusal wear in Phase III was associated with 1.94 times the occurrence of NCCLs in Phase III (P<.001). Occlusal interference in border movements of the mandible was associated with a 3.55 times greater chance of presenting NCCLs in Phase III (P<.001). Additionally, statistically significant risk factors for the presence of NCCLs in Phase III were an acidic diet (P=.043) and alcohol consumption (P=.021).

CONCLUSIONS

The 25-year data showed an association between NCCLs and specific risk factors, including occlusal wear and occlusal interferences.

Introspection of the Etiopathological Mechanisms Underlying Noncarious Cervical Lesions: Analysis of the Different Theories and Their Impact on the Mineralized Structures of the Tooth

The noncarious cervical lesions (NCCLs) recognize an etiological framework of onset very different from the carious processes with etiology whose bacteria aggregated in a biofilm play a predominant role, leading in this way to the loss of the mineralized structure of the tooth. The pathological picture of the NCCLs, which manifests itself with a clinical picture of dental wear, differs from caries because it mainly recognizes a series of pathological processes, such as erosion, through the action of generally acidic chemical agents and abrasion, which is basically expressed through repeated mechanical trauma characteristic of tooth brushing. However, in the literature, there is no unanimous agreement in identifying only these two mechanisms, but there are some who propose a more marked role of anomalous occlusal loads, which would be unloaded on some teeth which, in addition to both erosive and abrasive mechanisms, would give rise to abfraction. Therefore, the aim of this review was to collect literature etio-pathological information and discuss the mechanisms underlying NCCLs.

Risk factors of tooth wear in permanent dentition: A scoping review

BACKGROUND

Tooth wear (TW) prevalence is high and increasing and has important consequences on the patient's quality of life. Knowledge of risk factors is crucial to promote diagnosis, prevention strategies and timely interceptive treatment. Many studies have identified TW risk factors.

OBJECTIVE

This scoping review aims to map and describe suspected available factors associated with TW in permanent dentition based on quantitative measurement.

METHODS

The scoping review was conducted using the PRISMA extension of the Scoping Reviews checklist. The search was conducted in October 2022 from the Medline® (PubMed® interface) and Scopus® databases. Two independent reviewers selected and characterised the studies.

RESULTS

2702 articles were identified for assessment of titles and abstracts, and 273 articles were included in the review. The results show a need to standardise TW measurement indices and the study design. The included studies highlighted various factors, classified into nine domains: sociodemographic factors, medical history, drinking habits, eating habits, oral hygiene habits, dental factors, bruxism and temporomandibular disorders, behavioural factors, and stress. Results related to chemical TW (erosion) risk factors underline the importance of eating disorders, gastroesophageal reflux and lifestyle, particularly drinking and eating behaviours, which supports developing public health information campaigns and interventions. Besides chemical, this review identifies evidence of several mechanical TW risk factors, such as toothbrushing and bruxism; the influence of this last factor needs to be further explored.

CONCLUSIONS

TW management and prevention require a multidisciplinary approach. Dentists are in the first line to detect associated diseases such as reflux or eating disorders. Consequently, practitioners' information and guideline diffusion should be promoted, and a TW risk factors checklist (the ToWeR checklist) is proposed to help diagnostic approaches.

Three-dimensional evaluation of sleep bruxism-related splint wear using a dental laboratory scanner: A preliminary clinical study

BACKGROUND

The wear depth on the occlusal splint (OS) is reportedly associated with the sleep bruxism (SB) level, as evaluated using portable polysomnography (PSG) recordings. However, the OS is deformed owing to SB forces, possibly preventing the accurate quantification of the wear facets.

OBJECTIVES

We aimed to introduce a newly developed system to quantify the wear facets on the OS using a dental laboratory scanner (D810) and investigate the association between the wear facets, as evaluated with this system, and the SB level.

METHODS

Ten healthy individuals who were diagnosed with SB based on portable PSG recordings participated in this study. They were asked to wear the OS for 2 months. The first day after a 2-week adaptation period was defined as the reference day, and sequential scanning of the OS surface was performed on days 15, 30, and 45. Changes in the OS surface from the reference day allowed dimensional evaluation of the wear facets in terms of maximum wear depth, wear area, and wear volume. Multiple regression analyses were conducted to test whether each of these variables could be predicted by any of the SB-related variables.

RESULTS

The total duration of SB episodes per hour of sleep and the maximum muscle activity were significantly associated with the wear area, as measured with our system (adjusted R-squared was .78, p < .01).

CONCLUSION

Our system allows dimensional analysis of the wear facets on the OS surface in association with the SB level.

Oral and Dental Considerations of Combat-Induced Post Traumatic Stress Disorder (PTSD)-A Cross-Sectional Study

Objective: This study compared dental, periodontal, oral, and joint/muscle tenderness among Israeli combat-induced post-traumatic stress disorder (Ci-PTSD) war veterans to non-PTSD patients. Study design: This retrospective three-arm study compared oral and facial manifestations between 100 Israeli veterans with Ci- PTSD (study group) and 103 non-PTSD periodontal patients (Control group). The study group was further divided into two subgroups of individuals who received psychiatric medications (40 patients) or did not (60 patients). All patients underwent complete dental, oral, and periodontal examinations, including assessing signs of parafunction. Results: All PTSD patients had poor oral hygiene. The plaque index (PI) was higher in the PTSD group compared to the control group (0.72 ± 0.28 vs. 0.45 ± 0.29, respectively, p < 0.001). The decayed, missing, and filled teeth score (DMFt) was higher in the PTSD population than in the controls (19.97 ± 8.07 vs. 13.05 ± 6.23 p < 0.05). Severe periodontal disease was more common among the PTSD subgroup taking medications (med -group) (62.5%) compared to the nonmedicated group (non-med group) (30.0%) and the controls (27.2%) (p = 0.001). Heavy smoking was more prevalent in the medicated PTSD patients than in other groups. Conclusions: The present study shows higher morbidities in combat-induced PTSD patients, including oral, dental, and periodontal manifestations, especially in medicated patients.

Bone apposition at the mandibular angles as a radiological sign of bruxism: a retrospective study

Background

The main objective of this investigation was to determine on panoramic radiographs the prevalence of macroscopically visible alterations (bone apposition in combination with directional change) in the mandibular angle region in bruxism patients. Another aim was to describe and detect different morphological characteristics of the jaw angles.

Methods

Two hundred panoramic radiographs were studied: 100 images of adults with clinically diagnosed bruxism (73 women, 27 men, age range 21–83 years), 100 images of a comparison group consisting of adolescents (66 girls, 34 boys, age range 12–18 years).

Results

The morphological changes of the 400 jaw angles could be classified into four degrees. In the adult group, almost half of mandibular angles showed bone apposition. Conversely, the prevalence in the control group was zero. The localization of the appositions corresponds to the insertions of the masseter and medial pterygoid muscles at the mandibular angle.

Conclusions

The bone apposition at the mandibular angles should be interpreted as a functional adaptation to the long-term increased loads that occur during the contraction of the jaw closing muscles due to bruxism. Hence, radiologically diagnosed bone apposition may serve as an indication or confirmation of bruxism.

Occlusal problems, mental health issues and non-carious cervical lesions

Non-carious cervical lesions (NCCLs) are characterized by a loss of hard dental tissue near the cement-enamel junction with multifactorial etiology. The aim of this study was to demonstrate that occlusal factors as attrition, malocclusion, and bruxism, and mental disorders as depression, stress, and anxiety are involved in the etiology of NCCLs. Salivary samples and clinical data of 340 individuals selected from 6,112 participants were obtained from the University of Pittsburgh School of Dental Medicine Dental Registry and DNA Repository project. The affected group was formed by individuals with NCCL (34 females, 34 males, mean age 55.34 years). In addition, the comparison group was formed by individuals without NCCL (136 females, 136 males, mean age 55.14 years). Eleven single-nucleotide polymorphisms (SNPs) previously associated with mental disorders were genotyped and tested for association with NCCLs. When all occlusal factors were combined there was found a significant association with NCCL (p = 0.000001/adjusted OR 4.38, 95% CI 2.50-7.69). Attrition (OR 3.56, 95% CI 2.00-6.32) and malocclusion (OR 5.09, 95% CI 1.65-15.68) as separate variables showed statistically significant associations with NCCL. There was a significant difference in stress history between the two groups (OR 2.17, 95% CI 1.08-4.39). No associations between NCCLs and the SNPs selected were found. However, when the occlusal factors were analyzed as covariates, associations were found between bruxism and seven of the selected SNPs. Our results suggest that occlusal factors might be associated with NCCLs.

Bruxism

Bruxism is a parafunctional activity of the masticatory system, which is characterized by clenching or scraping of teeth. This condition is often accompanied by a change in the shape and size of the teeth, as well as the function of the stomatognathic system. Bruxism can occur during sleep and in the waking state. The etiology is multifactorial and all causes can be divided into peripheral and central. The clinical signs and symptoms of bruxism are primarily characterized by temporomandibular disorders, the appearance of bruxofacets and changes in the hard dental tissues, supporting apparatus of the teeth and masticatory muscles, as well as headaches. The diagnosis of bruxism is made on the basis of anamnesis and clinical signs and symptoms, while electromyography and polysomnographic analysis are used in scientific researches. Therapy is aimed at controlling etiological factors and reducing symptoms. Occlusal splints are the most commonly used in the treatment of bruxism. Medications are used in situations when other methods, including psychotherapy, do not give positive results. Given the multifactorial etiology, the therapeutic approach must be multidisciplinary. The approach to the patient must be individual in order to treat as effectively as possible.

The Role of Occlusal Factors in the Presence of Noncarious Cervical Lesions in Young People: A Case-Control Study

Objective:

The aim of this retrospective case-control study was to evaluate the influence of different occlusal characteristics and self-referred bruxism in the presence of noncarious cervical lesions (NCCLs).

Methods and Materials:

The participants were 280 students (140 cases and 140 controls), with an average age of 24.5 years, from six schools of dentistry in Spain. Clinical examination was carried out to record the NCCLs and the static and dynamic occlusal characteristics. The side of mastication and bruxism was collected by questionnaire. Data variables were analyzed by means of univariate and multivariate logistic regression. Odds ratios and the respective 95% confidence intervals were calculated (p&lt;0.05).

Results:

The presence of NCCLs was significantly more likely in subjects with protrusive interferences (odds ratio [OR]=1.82); with lateral interferences, especially on the nonworking side (OR= 1.77); or who were self-reported bruxists (OR=1.72). In the multivariate analysis, protrusive interferences, bruxism, age, and the presence of attrition were risk factors for the development of NCCLs. These factors resulted in a model with an area under the receiver-operating characteristic curve of 0.667 and a positive predictive value of 61.43%.

Conclusions:

There was no significant relationship between most occlusal factors and the presence of NCCLs. Only bruxism, protrusive interferences, age, and occlusal wear were risk factors. The predictive model was not sufficiently explanatory. Occlusal factors alone do not appear to be sufficient to explain the presence of NCCLs.

Bruxismo do sono: estudo de base populacional em pessoas com 18 anos ou mais na cidade de Rio Grande, Rio Grande do Sul

RESUMO: Objetivos: Avaliar a prevalência do bruxismo do sono, bem como seus principais sinais e sintomas, na cidade de Rio Grande, Rio Grande do Sul. Avaliar a associação do bruxismo do sono com sexo, idade, escolaridade e estresse psicológico. Método: O estudo foi do tipo transversal. Uma amostra representativa da população (1.280 pessoas residentes na zona urbana da cidade com idade maior ou igual a 18 anos de idade) foi entrevistada. A avaliação do bruxismo do sono foi realizada por meio de questionário baseado nos critérios diagnósticos da Classificação Internacional de Distúrbios do Sono. Resultados: A prevalência de bruxismo do sono encontrada na população foi de 8,1% (intervalo de confiança de 95% - IC95% - 6,6 - 9,5). Entre os sinais e sintomas da disfunção utilizados para o diagnóstico de bruxismo do sono, o desgaste dentário (70,3%) e a dor nos músculos mastigatórios (44,5%) foram os mais frequentemente relatados pelas pessoas que declararam ranger os dentes durante o sono. Não houve diferença significativa na prevalência de bruxismo do sono entre os sexos. A faixa etária com mais de 40 anos teve maior prevalência de bruxismo do sono. A disfunção foi associada a um maior nível de escolaridade (razão de prevalência - RP = 1,92; IC95% 1,35 - 2,72) e de estresse psicológico (RP = 1,76; IC95% 1,11 - 2,81). Conclusão: O bruxismo do sono tem uma importante prevalência na população em geral, causando diversos danos ao sistema estomatognático. O estresse psicológico é um fator de risco para essa disfunção.

Body-focused repetitive behaviors: More prevalent than once thought?

Body-focused repetitive behaviors (BFRBs), such as hair pulling, skin picking, and nail biting are common habits, but their pathological manifestations have been considered rare. Growing evidence suggests pathological forms of these behaviors can be conceptualized as a class of related disorders. However, few previous studies have examined the collective prevalence of related pathological BFRBs. The current study examined the self-reported prevalence of current (past month) subclinical and pathological BFRBs in a large (n = 4335) sample of college students. The study also examined the chronicity and impact of these behaviors. Results showed that 59.55% of the sample reported occasionally engaging in subclinical BFRBs, and 12.27% met criteria for a pathological BFRB, suggesting these conditions may be quite common. Of the various BFRB topographies, cheek biting was the most common. Both subclinical and pathological BFRBs tended to be chronic (i.e., occurring for longer than 1 year). Although persons with pathological BFRBs were distressed about their behavior, few experienced functional impairment or sought help for the behavior. Implications of these findings for the conceptualization and treatment of body-focused repetitive behaviors are discussed.

Associations among Bruxism, Gastroesophageal Reflux Disease, and Tooth Wear

The relationship between bruxism and tooth wear is contentious in the literature. The pathophysiological processes of tooth wear may be complicated by the relationship between bruxism and gastroesophageal reflux disease (GERD). The objective of this study was to evaluate the associations among bruxism, GERD, and tooth wear. Two complementary studies were performed: a case-control study to verify the linkage between GERD and bruxism and a cross-sectional study on the same cohort to establish the connection between GERD and tooth wear in bruxism patients. A cohort of 363 consecutive bruxism patients and 363 matched control participants were recruited. Gastroesophageal reflux disease was diagnosed in accordance with the Montreal criteria. Tooth wear was scored based on the index recommended by Smith and Knight. Logistic regression analyses were performed. After adjustment, GERD was identified as a risk factor of bruxism. Bruxism with reflux symptoms for extensive time-periods was associated with severe tooth wear for the whole dentition (odds ratio, 4.70, 95% confidence interval, 2.04–10.83). Increased odds ratios for severe tooth wear were also found in all tooth locations and palatal/lingual and occlusal/incisal surfaces of bruxism patients with GERD for extensive time-periods. In conclusion, strong associations were identified among bruxism, GERD, and tooth wear.

Non-carious cervical lesions and risk factors: A case-control study

OBJECTIVES

To evaluate whether the presence of non-carious cervical lesions (NCCLs) was related to the considered risk factors and to show the corresponding odds ratio in a predictive model.

METHODS

The sample was 280 dentistry students. In an initial clinical examination, 140 cases were selected that presented one or more teeth with non-carious cervical wear. For each case, a similar sex and age control without any tooth with non-carious cervical lesions was selected. An occlusal examination and periodontal probing were performed in all cases and controls by skilled dentists. All the subjects answered a questionnaire referring to factors of brushing, bruxism, preferred chewing side, consumption of extrinsic acids and the presence of intrinsic acids. Data were analysed by means of univariate and multivariate logistic regression.

RESULTS

Of all the study variables, only the protrusion interferences, interferences on the non-working side, the brushing force, CPITN value and the consumption of salads increase the risk of NCCLs in the univariate regression. The best predictive model was formed by the combination of CPITN variables >1, the consumption of acidic salads, self-reported bruxism, brushing force and attrition. However, it only correctly classifies 68.75% of subjects.

CONCLUSIONS

This study supports the multifactorial aetiology of NCCLs, the combination of several factors being necessary to explain their presence. The risk factors that make up the predictive model are not sufficient to explain the appearance of NCCLs. Dentists should take into account all these risk factors in prevention, diagnosis and treatment.

Association between buccal mucosa ridging and oral or occlusal status among older people

OBJECTIVES

This study aimed to evaluate the association between buccal mucosa ridging and oral or occlusal statuses among older people.

SUBJECTS AND METHODS

This cross-sectional study examined 262 independent older people (mean age, 74.2 ± 5.9 years) who participated in the Kyoto Elderly Physical Fitness Measurement Research Project. The predictor variables were oral statuses (number of present teeth and torus palatinus, torus mandibularis, temporomandibular joint noise, clenching, or grinding) and oral functions (occlusal pressure, cheek pressure, oral diadochokinesis, and tongue pressure). The outcome variable was the buccal mucosa ridging status (presence or absence). Additional variables were age, sex, body mass index, grip strength, and wearing dentures. We compared these variables between participants with and without buccal mucosa ridging using a univariate analysis and multiple logistic regression analysis.

RESULTS

Buccal mucosa ridging was present in 177 (67.6%) people. Multiple logistic regression analysis revealed a close association of buccal mucosa ridging with torus mandibularis, tooth clenching and grinding and occlusal pressure, and cheek pressure.

CONCLUSIONS

Over 50% of the participants showed buccal mucosa ridging; this was significantly associated with higher cheek pressure, lower occlusal pressure, torus mandibularis, and tooth clenching and grinding.

Potential orofacial hazards of resistance training: A controlled comparative study. Cranio 2017;37:45-52. [PMID: 28876194 DOI: 10.1080/08869634.2017.1370566]

OBJECTIVE

To evaluate the effect of resistance training (RT) regarding potential hazard for dental wear, tooth abfractions, temporomandibular joint disc displacement, limitation in mouth opening, and existence of cervical spine disorders. The initial study hypothesis was that extensive resistance trainees (ExRT) would suffer from the above-mentioned symptoms more often than recreational trainees (RcT).

METHODS

A controlled comparative study among male gym members via questionnaires and a clinical examination.

RESULTS

ExRT had a higher prevalence of teeth indentations on the tongue (26% vs. 2% p < 0.001) and a higher prevalence of tooth abfractions than RcT (28% vs. 4% p < 0.005). ExRT exhibited a higher prevalence of cervical movement limitations (p < 0.05) and inadequate posture (p < 0.001).

CONCLUSION

RT by itself may not be a risk factor for disc displacement. Nevertheless, it may act as a potential risk factor for irreversible hard tooth tissue damage and contribute to neck postural and mobility impairments.

Whistle Abrasion: A Case Report

Abrasion is the physical wearing of a tooth surface which can involve the presence of a foreign object repeatedly being in contact with the tooth. A 40-year-old male patient reported to our dental clinic with a 2–3 mm uneven gap between his upper and lower front teeth on occlusion. A detailed history revealed that he was a physical education teacher, and the habitual placement of the whistle for the last 15 years caused an indentation on the whistle which coincided with the abraded teeth. Conditions such as abrasion may need active restorations. A general dental practitioner should accurately identify the cause and treat the esthetic and functional impairment as required.

Tardive Dyskinesia, Oral Parafunction, and Implant-Supported Rehabilitation

Oral movement disorders may lead to prosthesis and implant failure due to excessive loading. We report on an edentulous patient suffering from drug-induced tardive dyskinesia (TD) and oral parafunction (OP) rehabilitated with implant-supported screw-retained prostheses. The frequency and intensity of the movements were high, and no pharmacological intervention was possible. Moreover, the patient refused night-time splint therapy. A series of implant and prosthetic failures were experienced. Implant failures were all in the maxilla and stopped when a rigid titanium structure was placed to connect implants. Ad hoc designed studies are desirable to elucidate the mutual influence between oral movement disorders and implant-supported rehabilitation.

Factors influencing the progression of noncarious cervical lesions: A 5-year prospective clinical evaluation

STATEMENT OF PROBLEM

The etiology (chemical, friction, abfraction) of noncarious cervical lesion (NCCL) progression is poorly understood.

PURPOSE

The purpose of this 5-year prospective clinical trial was to measure the relationship between NCCLs and various etiologic factors.

MATERIAL AND METHODS

After review board approval, 29 participants with NCCLs were enrolled. Polyvinyl siloxane impressions were made of each NCCL, and casts were poured at baseline, 1, 2, and 5 years. The casts were scanned with a noncontact profilometer, and 1-, 2-, and 5-year scans were superimposed over baseline scans to measure volumetric change in NCCLs. T-scan and Fujifilm Prescale films were used to record relative and absolute occlusal forces on teeth with NCCLs at the 5-year recall. Participant diet, medical condition, toothbrushing, and adverse oral habit questionnaires were given at the 5-year recall. Occlusal analysis was completed on mounted casts to determine the presence of wear facets and group function. Volumetric lesion progression from 1 to 5 years was correlated to absolute and relative occlusal force using mixed model analysis. The Kruskall-Wallis and Mann-Whitney analyses compared lesion progression with diet, medical condition, toothbrushing, adverse oral habits, wear facets, and group function.

RESULTS

The NCCL progression rate over 5 years was 1.50 ±0.92 mm(3)/yr. The rate of progression of NCCLs was related to mean occlusal stress (P=.011) and relative occlusal force (P=.032) in maximum intercuspation position. No difference was seen in NCCL progression between participants with any other factors.

CONCLUSION

Heavy occlusal forces play a significant role in the progression of NCCLs.

Efficacy of biofeedback therapy via a mini wireless device on sleep bruxism contrasted with occlusal splint: a pilot study

The putative causes of bruxism are multifactorial and there are no definite measures for bruxism management. The aim of this study was to evaluate the efficacy of biofeedback therapy on sleep bruxism, compared with occlusal splint. Twenty-four volunteers with sleep bruxism were divided into two groups: the GTB group that were treated with biofeedback therapy (n  = 12) and the GTO group that were treated with occlusal splint (n  = 12). A mini pressure sensor integrated with a monitoring circuit by use of a maxillary biofeedback splint was fabricated. To foster the relaxation of the masticatory muscles and the nervous system, the wireless device received signals from bruxism events and vibrations alerted the bruxer when the threshold was exceeded. Total episodes and average duration of bruxism events during 8 hours of sleep were analyzed with the monitoring program (TRMY1.0). After 6 and 12 weeks, the episodes (P  =  0.001) and duration (P < 0.05) in the GTB group declined dramatically. In contrast, there were no significant differences in the GTO group after the treatment (P > 0.05). Furthermore, the episodes had significant differences between the GTB group and the GTO group after the same period of treatment (P  =  0.000). The results suggest that biofeedback therapy may be an effective and convenient measure for mild bruxers, when compared with occlusal splint therapy. The mini wireless biofeedback method may be of value for the diagnosis and management of bruxism in the future.

Orofacial pain and headache: a review and look at the commonalities

Headache and facial pain - in particular, temporomandibular disorders (TMDs) - are very prevalent conditions in the general population. TMDs are defined as a collection of symptoms and signs involving masticatory muscles, the temporomandibular joints (TMJs), or both. The pain reported by TMD patients is typically located in the muscles of mastication, in the preauricular area, or in the TMJs. In many cases, headaches and facial pain will occur in the same patient. Much of the research relative to the relationship of these disorders focuses on statistics of association and prevalence data. This review will provide a brief description of the types and classifications of orofacial pains (OFPs), as well as point to relevant research describing the commonalities and potential comorbid nature of these maladies. Finally, several recent papers describing morphologic changes to the brain in headache and TMD individuals will be discussed in an effort to stimulate further research into the potential common pathophysiologic mechanism that may explain the comorbid nature of these disorders.

Occlusal stability

Occlusion is the foundation for clinical success in fixed, removable, and implant prosthodontic treatment. Understanding those principles is critical when restoring a patient's occlusion. Many philosophies, devices, and theories of occlusion have evolved based on anecdotal clinical observations and applied geometric perceptions. The literature has reported these classic and contemporary occlusal concepts. As evidence-based dentistry emerged, it championed scrutiny of previously held beliefs, resulting in the abandonment of many pragmatic, yet beneficial occlusal procedures. The impetus toward scientific discovery, whereby factual information might be universally applied in dental education and clinical practice, has renewed interest in occlusal studies.

Oral tori are associated with local mechanical and systemic factors: a case-control study

PURPOSE

To estimate if various dental factors, medications, and medical conditions are associated with an increased risk for the presence of oral tori.

MATERIALS AND METHODS

Using a case-control study design, the investigators identified and adjudicated a sample of cases with torus palatinus (TP) and/or torus mandibularis (TM) during a 1.5-year period. The medical records were abstracted and data on dental factors, temporomandibular dysfunction (TMD), medications, and medical conditions were recorded. Risk estimates were calculated as adjusted odds ratios (AORs) with 95% confidence intervals (CIs) using conditional logistic regression analyses, and the P value was set at .05.

RESULTS

The sample was composed of 66 subjects with TM, 34 subjects with TP, and 100 control subjects from the same database. Any form of oral torus (TP and/or TM) was associated significantly with TMD (AOR, 10.51; 95% CI, 4.46 to 24.78; P<.01) and tooth attrition (AOR, 5.22; 95% CI, 2.32 to 11.77; P<.01). TP was associated significantly with TMD (AOR, 4.14; 95% CI, 1.21 to 14.21; P<.05), tooth attrition (AOR, 38.18; 95% CI, 7.20 to 202.41; P<.01), and treated hypertension (AOR, 6.64; 95% CI, 1.31 to 33.57; P<.05). TM was associated significantly with TMD (AOR, 5.77; 95% CI, 2.38 to 13.98; P<.01), tooth attrition (AOR, 6.69; 95% CI, 2.78 to 16.14; P<.01), and a penicillin allergy (AOR, 4.45; 95% CI, 1.05 to 18.83; P<.05).

CONCLUSIONS

This study provides clinical evidence showing significant associations between oral tori and various dental factors, medications, and medical conditions. These findings add to the list of environmental factors believed to contribute to the formation of oral tori.

Stress analysis of occlusal forces in canine teeth and their role in the development of non-carious cervical lesions: abfraction

Non-carious cervical tooth lesions for many decades were attributed to the effects of abrasion and erosion mainly through toothbrush trauma, abrasive toothpaste, and erosive acids. However, though the above may be involved, more recently a biomechanical theory for the formation of these lesions has arisen, and the term abfraction was coined. The aim of this study was to investigate the biomechanics of abfraction lesions in upper canine teeth under axial and lateral loading conditions using a three-dimensional finite element analysis. An extracted human upper canine tooth was scanned by μCT machine (Skyscan, Belgium). These μCT scans were segmented, reconstructed, and meshed using ScanIP (Simpleware, Exeter, UK) to create a three-dimensional finite element model. A 100 N load was applied axially at the incisal edge and laterally at 45° midpalatally to the long axis of the canine tooth. Separately, 200 N axial and non-axial loads were applied simultaneously to the tooth. It was found that stresses were concentrated at the CEJ in all scenarios. Lateral loading produced maximum stresses greater than axial loading, and pulp tissues, however, experienced minimum levels of stresses. This study has contributed towards the understanding of the aetiology of non-carious cervical lesions which is a key in their clinical management.

Non-carious cervical lesions and occlusion: a systematic review of clinical studies

Non-carious cervical lesions (NCCLs) are a group of lesions that affect the cervical area of the teeth. Different aetiological factors have been reported, among them tooth brushing force, erosive agents and occlusal forces. The aim of this study was to ascertain, by means of a systematic review, the association between NCCLs and occlusion. A search was performed in the MEDLINE database, retrieving a total of 286 articles. After title and abstract screening, the clinical investigations were read in full to select those that evaluated the occlusal aspects of NCCL aetiology. This systematic review describes the results of three prospective and 25 cross-sectional studies. As there is an extreme heterogeneity in design, diagnostic criteria, forms of analysis and associated factors, a meta-analysis was not possible. The wide variety of classification and diagnostic criteria reflects a high range of reported prevalence. An extensive heterogeneity of independent variables was noted, even in occlusal analysis, which helps to mask any conclusion about the role of occlusion in NCCL aetiology. The literature reveals that studies on this topic are subject to a substantial amount of bias, such as evaluation (use of non-blinded examiners) and confounding bias (no control of others aetiological factors). Up to now, it has been impossible to associate NCCLs with any specific causal agent, and the role of occlusion in the pathogenesis of non-carious cervical lesions seems as yet undetermined. Therefore, additional studies, properly designed to diminish bias, are warranted.

Restoration of noncarious cervical lesions: when, why, and how

At this time, restoration of noncarious cervical lesions (NCCLs) is a common occurrence in clinics nowadays. Some reasons for this are the growth of the elderly population, a smaller rate of tooth loss, and possibly the increase of some etiologic factors. These factors include inadequate brushing techniques in gingival recession cases, corrosive food and drink consumption, and occlusal stress concentrating factors (occlusal interferences, premature contacts, habits of bruxism, and clenching). Unfortunately, Class V restorations also represent one of the less durable types of restorations and have a high index of loss of retention, marginal excess, and secondary caries. Some causes for these problems include difficulties in isolation, insertion, contouring, and finishing and polishing procedures. This work aims to help dentists in choosing the best treatment strategy, which necessarily involves steps of problem identification, diagnosis, etiological factor removal or treatment, and, if necessary, restoration. Finally, appropriate restorative techniques are suggested for each situation.

fMRI study of brain activity elicited by oral parafunctional movements

Parafunctional masticatory activity, such as the tooth clenching and grinding that is associated with bruxism, is encountered by clinicians in many disciplines, including dentistry, neurology and psychiatry. Despite this, little is known about the neurological basis for these activities. To identify the brain network engaged in such complex oromotor activity, functional magnetic resonance imaging (fMRI) was used to elucidate the brain activation patterns of 20 individuals (10 males and 10 females, mean s.d. age of 26.3+/-4.1 years) with (parafunctional, PFx group, 5M/5F) and without (normal functional, NFx group, 5 M/5F) self-reported parafunctional grinding and clenching habits during clenching and grinding tasks. Subject group classification was based on: (i) self-reported history, (ii) clinical examination, (iii) evaluation of dental casts and (iv) positive responses to the temporomandibular disorder (TMD) History Questionnaire [Dworkinand LeResche, Journal of Craniomandibular Disorders, (1992) 6:301]. While subjects performed these oromotor tasks, each wore a custom-designed oral appliance minimizing head motion during imaging. Mean per cent signal changes showed significant between group differences in motor cortical (supplementary motor area, sensorimotor cortex and rolandic operculum) and subcortical (caudate) regions. Supplementary motor area data suggest that motor planning and initiation, particularly during the act of clenching, are less prominent in individuals with oromotor parafunctional behaviours. The overall extent of activated areas was reduced in subjects with self-reported parafunctional masticatory activity compared with the controls. This study's methodology and findings provide an initial step in understanding the neurological basis of parafunctional masticatory activities that are relevant for therapeutic research applications of temporomandibular joint and muscle disorders and associated comorbidities.

Tooth wear: prevalence and associated factors in general practice patients

OBJECTIVES

To estimate the prevalence of tooth wear and to investigate factors associated with tooth wear in patients from general practices in the Northwest United States.

METHODS

Data on the diagnosis and treatment of oral diseases during the previous year were collected in a survey with a systematic random sample of patients (n= 1530) visiting general dentists from the Northwest Practice-based REsearch Collaborative in Evidence-based DENTistry (PRECEDENT) (n=80). Prevalence ratios (PRs) of moderate to severe occlusal and incisal tooth wear by patient characteristics were estimated using cluster-adjusted multiple binomial regression for adults (18+ years) and children/adolescents (3-17 years).

RESULTS

For adults, the mean number of teeth with wear facets was 5.4 [95% confidence interval (CI) =4.6-6.2] and 51% of the adults had four or more teeth with wear. Participants 45-64 and 65+ years old were 1.3 (95% CI=1.1-1.6) and 1.4 (95% CI=1.1-1.8) times as likely to have 4+ teeth with moderate to severe wear facets as participants 18-44 years old. Adult males had a 20% (PR=1.2; 95% CI=1.1-1.4) higher prevalence of wear than adult females. Adults who were using, or had ever used occlusal splints had higher prevalence of tooth wear compared to those who never used such appliances (PR=1.3; 95% CI=1.0-1.5). Adults with any periodontal bone loss also had a 20% higher prevalence of wear than adults without periodontal disease (PR=1.2; 95% CI=1.0-1.4). For children/adolescents, the mean number of teeth with moderate to severe wear facets was 1.6 (95% CI=0.9-2.6) and 31% of the children had one or more teeth with wear facets. The adjusted prevalence ratio of tooth wear (1+ teeth with wear facets) for boys was 1.6 times as high (95% CI=1.1-2.4) as compared with girls. The prevalence of wear for children 12+ years old was 50% (PR=0.5; 95% CI=0.3-0.8) lower than that of children <12 years old. Angle's class II was associated with higher tooth wear prevalence (PR= 1.8; 95% CI=1.3-2.6) than class I. Children with posterior or anterior open bite had lower prevalence of wear than their counterparts (PR=0.6; 95% CI=0.3-1.0). No associations were observed between tooth wear and orthodontic treatment, missing teeth, and race/ethnicity.

CONCLUSION

Tooth wear is a prevalent condition in this population. Among adults, higher prevalences of tooth wear were observed among those who were older, males, had used occlusal splints and had periodontal disease. Among children, higher prevalences were associated with younger age, male gender, class II malocclusion and the absence of open bite. Submitted on behalf of the Northwest PRECEDENT network, with support from NIDCR grants DE016750 and DE016752.

The effect of age on the gingival crevicular fluid composition during experimental gingivitis. A pilot study

Background:

Cytokines have been proposed as potentially useful diagnostic or prognostic markers of periodontal inflammation related alterations during the experimental gingivitis model. The role of ageing in periodontal disease needs further elucidation; therefore investigations of its influence on host response are needed.

Objective:

To study the effect of age on interleukins IL -6, IL-8 and TNF-a levels in gingival crevicular fluid (GCF) and their correlations to clinical parameters during experimental gingivitis.

Materials and Methods: Five young subjects (20-22 years old) and five old subjects (61-65 years old), all periodontal healthy, participated in this clinical trial. A professional plaque control programme was undertaken to establish healthy gingival conditions at baseline. Plaque index (PI), gingival index (GI) were recorded at 60 sites at baseline, after 21 days of no oral hygiene and one week later after professional cleaning and reestablishment of oral hygiene procedures. A total of 180 samples were analyzed with ELISA for levels of IL -6, IL-8 and TNF-a in gingival crevicular fluid. The examination included the mesiobuccal sites of the Ramfjord teeth. Comparisons between and within groups were performed by non-parametric tests (Mann- Withney) and correlations were sought for with Wilcoxon test. Significance was set at p=0.05.

Results:

Results showed significant diferences between the two groups with regard to the plaque and bleeding scores and GCF volume, all of which proved to be more pronounced in old group. With respect to laboratory data, mean cytokine concentrations were in general lower in young group. TNF-a had a steady increase for the adults, which was found to be statistically significant between Days 0 and 21, IL-8 showed a statistically significant decrease at Day 28 in the young group and finally IL-6 showed a fluctuation, which was totally adverse for the two groups at each time point.

Conclusion:

Within the limitations of the present study, age cannot be identified as a factor that strongly affects the cytokine expression and fluctuations even in a well-controlled environment of inflammation, such as experimental gingivitis.