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.

Natural History of Mandibular Function in Spinal Muscular Atrophy Types 2 and 3.

Background: Hereditary proximal spinal muscular atrophy (SMA) is characterized by abnormal alpha motor neuron function in brainstem and spinal cord. Bulbar dysfunction, including limited mouth opening, is present in the majority of patients with SMA but it is unknown if and how these problems change during disease course. Objective: In this prospective, observational, longitudinal natural history study we aimed to study bulbar dysfunction in patients with SMA types 2 and 3. Methods: We included 44 patients with SMA types 2 and 3 (mean age was 33.6 (95% CI 28.4;38.9) and re-examined them after on average 4 years. None were treated with SMN-modulating treatments before or during the course of this study. Longitudinal assessments included a questionnaire on mandibular and bulbar function, the Mandibular Function Impairment Questionnaire (MFIQ), and a clinical examination of masticatory performance, maximum voluntary bite force, and mandibular movements including the active maximal mouth opening. Results: We found significant higher MFIQ scores and a significant decrease of all mandibular movements in patients with SMA type 2 (p < 0.001), but not in SMA type 3. Masticatory performance and maximum voluntary bite force did not change significantly. Mean reduction of active maximal mouth opening at follow-up was 3.5 mm in SMA type 2 (95% CI: 2.3; 4.7, p < 0.001). SMA type 2 was an independent predictor for a more severe reduction of the mouth opening (ß= -2.0 mm (95% CI: -3.8; -0.1, p = 0.043)). Conclusions: Bulbar functions such as mandibular mobility and active maximum mouth opening decrease significantly over the course of four years in patients with SMA type 2.

Inter- and intra-variability in tooth wear progression at surface-, tooth- and patient-level over a period of three years: A cohort study: Inter- and intra-variation in tooth wear progression.

OBJECTIVE: To explore the variability of tooth wear progression at the surface-, tooth- and patient-level over a period of three years three years using in vivo 3D-measurements of full dentitions amongst patients with moderate to severe tooth wear and without demand for restorative rehabilitation. METHODS: Fifty-five eligible patients with moderate to severe tooth wear had intra-oral scans taken using either the 3 M True Definition Intraoral Scanner or the 3 M Lava Chairside Oral Scanner. The maximum height loss (µm) per cusp/incisal/palatal surface at unrestored surfaces was measured using the 3D Wear Analysis (3DWA)-protocol with Geomagic Qualify, resulting in sixty-four measurements per dentition. Data was visualized using box plots. Correlation was calculated between tooth wear progression rates of different tooth types and surfaces. RESULTS: Thirty patients with scans at intake and after three years were included (38 ± 8 years, 77% M, 23% F). Mean observation time was 3.1 ± 0.2 years. Surface measurements (N = 1,615) showed a high deviation and a high number of outliers at all surfaces, indicating large variability amongst the surfaces, tooth types and patients with tooth wear progression rates. Correlations between regions were very low: anterior-molar region -0.219, anterior-premolar region 0.116 and premolar-molar region 0.113. Correlations between the surfaces of molars were also low (between 0.190 and 0.565). CONCLUSIONS: In a group of patients with moderate to severe tooth wear, large differences in wear progression were found within and amongst patients. Tooth wear progression is therefore highly individualized and can be very localized. CLINICAL SIGNIFICANCE: This study confirms the necessity of individual management of patients with moderate to severe tooth wear. Effective monitoring of tooth wear is important when deciding the timing and need for restorative intervention. CLINICAL TRIAL REGISTRATION NUMBER: NCT04790110.

Diagnostics and Management of Pediatric Headache: An Exploratory Study among Dutch Physical Therapists.

Physiotherapists are often part of a multidisciplinary treatment plan for children with headaches. The literature on physical therapeutic diagnostics and management of headaches is often focused on adults. To gain insight, identify knowledge gaps, and increase the evidence needed for clinical physical therapeutic practice with children with headaches, an exploratory method is warranted. The purpose of this study was to describe the views, beliefs, and experiences of physical therapists regarding diagnostics and treatment options for children with headaches. The method consisted of a survey and two peer consultation group meetings. A total of 195 individual surveys were returned and 31 out of 47 peer consultation groups participated. Most participants were specialized in pediatric physical therapy (93.3%). They use the 4P-factor model (predisposing, precipitating, perpetuating, and protective factors) as a guiding principle in the diagnostic and therapeutic process in children with headaches. This model helps to organize and to understand how a variety of factors interact in a biopsychosocial relationship. Pediatric physical therapists focus their treatments on factors interfering with movement and functional abilities of the child with headaches. Knowledge of how temporomandibular disfunction can relate to headaches is currently insufficient for pediatric physical therapists.

Diagnostic criteria for temporomandibular disorders-INfORM recommendations: Comprehensive and short-form adaptations for adolescents.

BACKGROUND: The Diagnostic Criteria for Temporomandibular Disorders (DC/TMD) for use in adults is in use worldwide. Until now, no version of this instrument for use in adolescents has been proposed. OBJECTIVE: To present comprehensive and short-form adaptations of the adult version of DC/TMD that are appropriate for use with adolescents in clinical and research settings. METHODS: International experts in TMDs and experts in pain psychology participated in a Delphi process to identify ways of adapting the DC/TMD protocol for physical and psychosocial assessment of adolescents. RESULTS: The proposed adaptation defines adolescence as ages 10-19 years. Changes in the physical diagnosis (Axis I) include (i) adapting the language of the Demographics and the Symptom Questionnaires to be developmentally appropriate for adolescents, (ii) adding two general health questionnaires, one for the adolescent patient and one for their caregivers and (iii) replacing the TMD Pain Screener with the 3Q/TMD questionnaire. Changes in the psychosocial assessment (Axis II) include (i) adapting the language of the Graded Chronic Pain Scale to be developmentally appropriate for adolescents, (ii) adding anxiety and depression assessment that have been validated for adolescents and (iii) adding three constructs (stress, catastrophizing and sleep disorders) to assess psychosocial functioning in adolescents. CONCLUSION: The recommended DC/TMD, including Axis I and Axis II for adolescents, is appropriate to use in clinical and research settings. This adapted first version for adolescents includes changes in Axis I and Axis II requiring reliability and validity testing in international settings. Official translations of the comprehensive and short-form to different languages according to INfORM requirements will enable a worldwide dissemination and implementation.

Diagnostic criteria for temporomandibular disorders-INfORM recommendations: Comprehensive and short-form adaptations for children.

BACKGROUND: The Diagnostic Criteria for Temporomandibular Disorders (DC/TMD) are used worldwide in adults. Until now, no adaptation for use in children has been proposed. OBJECTIVE: The aim of this study was to present comprehensive and short-form adaptations of Axis I and Axis II of the DC/TMD for adults that are appropriate for use with children in clinical and research settings. METHODS: Global Delphi studies with experts in TMDs and in pain psychology identified ways of adapting the DC/TMD for children. RESULTS: The proposed adaptation is suitable for children aged 6-9 years. Proposed changes in Axis I include (i) adapting the language of the Demographics and the Symptom Questionnaires to be developmentally appropriate for children, (ii) adding a general health questionnaire for children and one for their parents, (iii) replacing the TMD Pain Screener with the 3Q/TMD questionnaire and (iv) modifying the clinical examination protocol. Proposed changes in Axis II include (i) for the Graded Chronic Pain Scale, to be developmentally appropriate for children, (ii) adding anxiety and depression assessments that have been validated in children and (iii) adding three constructs (stress, catastrophising and sleep disorders) to assess psychosocial functioning in children. CONCLUSION: The recommended DC/TMD, including Axis I and Axis II, for children aged 6-9 years, is appropriate for use in clinical and research settings. This adapted the first version for children includes changes in Axis I and Axis II changes requiring reliability and validity testing in international settings. Official translations to different languages according to INfORM requirements will enable a worldwide dissemination and implementation.

Precision of In Vivo Quantitative Tooth Wear Measurement using Intra-Oral Scans.

Quantitative wear measurement is of increasing interest for measuring tooth wear progression. However, most research on quantitative wear measurement has focused on simulated wear or scanned gypsum casts. A 3D Wear Analysis (3DWA) protocol has been developed that analyzes tooth wear in vivo through intra-oral scanners available to dental clinicians. This study investigated the precision of the 3DWA protocol for measuring wear through maximum height loss (mm) and volume change (mm3). Observational prospective wear data from 55 patients were analyzed after 0-1-, 0-3-, and 0-5-year intervals to determine rates of wear, and convenience samples were chosen to test the protocol's precision on dentitions scanned twice in one sitting and its intra- and inter-rater precision on scans with 0-3- and 0-5-year intervals. Scans were made using intra-oral scanners (IOS) and superimposed using 3D measurement software. T-tests were performed to determine the structural and random error, and trimmed ranges were calculated to interpret the error. For protocol precision, the mean difference was 0.015 mm (-0.002; 0.032, p = 0.076) for height and -0.111 mm3 (-0.250; 0.023, p = 0.101) for volume. The duplicate measurement error was 0.062 mm for height and 0.268 mm3 for volume. The height measurements were precise enough to measure wear after intervals of 0-3 or 0-5 years; however, volume measurements were susceptible to procedural error and operator sensitivity. The 3DWA protocol is precise enough to adequately measure tooth height loss after intervals of a minimum of 3 years or in patients with severe wear progression, but it is not suited to measuring volumetric changes.

Diagnostic criteria for temporomandibular disorders in children and adolescents: An international Delphi study-Part 2-Development of Axis II.

BACKGROUND: Unlike the psychosocial assessment established for adults in the Diagnostic Criteria for Temporomandibular Disorders (DC/TMD), a standardised psychosocial assessment for children and adolescents with TMD complaints has not yet been established. OBJECTIVES: To develop a new standardised instrument set to assess the psychosocial functioning in children and adolescents by adapting the psychosocial status and pain-related disability (Axis II) of the adult DC/TMD and by including new instruments. METHODS: A modified Delphi method was used to survey 23 international TMD experts and four international experts in pain-related psychological factors for consensus regarding assessment tools for psychosocial functioning and pain-related disability in children and adolescents. The TMD experts reviewed 29 Axis II statements at round 1, 13 at round 2 and 2 at round 3. Agreement was set at 80% for first-round consensus level and 70% for each of the second and third rounds. The psychological experts completed a complementary Delphi survey to reach a consensus on tools to use to assess more complex psychological domains in children and adolescents. For the psychological experts, the first round included 10 open-ended questions on preferred screening tools for depression, anxiety, catastrophising, sleep problems and stress in children (ages 6-9 years old) and adolescents (ages 10-19 years old) as well as on other domains suggested for investigation. In the second round, the psychological experts received a 9-item questionnaire to prioritise the suggested instruments from most to least recommended. RESULTS: The TMD experts, after three Delphi rounds, reached consensus on the changes of DC/TMD to create a form to evaluate Axis II in children and adolescents with TMD complaints. The psychological experts added tools to assess depression and anxiety, sleep disorders, catastrophising, stress and resilience. CONCLUSION: Through international expert consensus, this study adapted Axis II of the adult DC/TMD to assess psychosocial functioning and pain-related disability in children and adolescents. The adapted Axis II protocols will be validated in the target populations.

Diagnostic criteria for temporomandibular disorders (DC/TMD) for children and adolescents: An international Delphi study-Part 1-Development of Axis I.

BACKGROUND: Since in children and adolescence prevalence is assessed mainly on self-reported or proxy-reported signs and symptoms; there is a need to develop a more comprehensive standardised process for the collection of clinical information and the diagnosis of TMD in these populations. OBJECTIVE: To develop new instruments and to adapt the diagnostic criteria for temporomandibular disorders (DC/TMD) for the evaluation of TMD in children and adolescents. METHOD: A modified Delphi method was used to seek international consensus among TMD experts. Fourteen clinicians and researchers in the field of oro-facial pain and TMD worldwide were invited to participate in a workshop initiated by the International Network for Orofacial Pain and Related Disorders Methodology (INfORM scientific network) at the General Session of the International Association for Dental Research (IADR, London 2018), as the first step in the Delphi process. Participants discussed the protocols required to make physical diagnoses included in the Axis I of the DC/TMD. Thereafter, nine experts in the field were added, and the first Delphi round was created. This survey included 60 statements for Axis I, and the experts were asked to respond to each statement on a five-item Likert scale ranging from 'Strongly disagree' to 'Strongly agree'. Consensus level was set at 80% agreement for the first round, and at 70% for the next. RESULTS: After three rounds of the Delphi process, a consensus among TMD experts was achieved and two adapted DC/TMD protocols for Axis I physical diagnoses for children and adolescents were developed. CONCLUSION: Through international consensus among TMD experts, this study adapted the Axis I of the DC/TMD for use in evaluating TMD in children and adolescents.

Combined orthodontic and surgical treatment for a patient with Hallermann-Streiff-Francois syndrome, severe obstructive sleep apnea, and history of antiresorptive medication.

Micrognathia and retrognathia, as observed in patients with the Hallermann-Streiff-Francois syndrome, might result in obstructive sleep apnea syndrome. When it becomes severe (apnea-hypopnea index [AHI], ≥30), noninvasive treatment options might be insufficient. An orthognathic treatment with mandibular advancement will increase the upper airway volume, which results in a decrease of apneas. A 53-year-old woman with Hallermann-Streiff-Francois syndrome and a history of antiresorptive medication suffered from severe obstructive sleep apnea (AHI, 77.7). She was treated with a combined orthodontic and surgical approach. The AHI decreased to 1, and the patient felt fitter after treatment. No medication-induced osteonecrosis nor inhibition of tooth movement was seen. A combined orthodontic and surgical treatment of a patient with severe obstructive sleep apnea was a good treatment choice. With a history of antiresorptive medication, the risks related to these medications have to be weighed up against the consequences of not treating obstructive sleep apnea syndrome. With a drug holiday, successful surgical treatment can be achieved.

Physical Treatments Reduce Pain in Children with Tension-Type Headache: A Systematic Review and Meta-Analysis.

AIMS: To assess the effectiveness of a variety of physical treatments in the management of tension-type headache (TTH) in children. METHODS: This review is reported in accordance with the PRISMA guidelines and was registered in the PROSPERO database (CRD42014015290). Randomized and nonrandomized controlled trials that examined the effects of all treatments with a physical component in the management of TTH in children and compared these treatments to a placebo intervention, no intervention, or a controlled comparison intervention were included. The Physiotherapy Evidence Database (PEDro) criteria for bias assessment and the Grades of Recommendation, Assessment, Development, and Evaluation (GRADE) Working Group criteria were used to assess the quality of the body of evidence. The outcome measures were pain, functioning, and quality of life. Only RCTs were included in the meta-analyses. RESULTS: An initial search produced 10,464 published articles. Of these, 17 were relevant trials, including 1,815 participants. The overall GRADE rating of the included studies was moderate, and 11 of the 17 studies could be used in the meta-analyses. The effectiveness of physical treatments in terms of a reduction of pain of 50% or more showed a risk ratio (RR) of 2.37 (95% CI: 1.69 to 3.33). Relaxation training was the most evaluated intervention and proved to be significantly effective (RR: 3.00 [95% CI: 1.94 to 4.63]). In children having TTH combined with temporomandibular disorders, occlusal appliances were effective (RR: 2.58 [95% CI: 1.37 to 4.85]). CONCLUSION: This review supports the use of physical treatments to reduce pain in children with TTH.

Coherence of jaw and neck muscle activity during sleep bruxism.

BACKGROUND: Studies have shown co-contraction of jaw and neck muscles in healthy subjects during (sub) maximum voluntary jaw clenching, indicating functional inter-relation between these muscles during awake bruxism. So far, coherence of jaw and neck muscles has not been evaluated during either awake or sleep bruxism. OBJECTIVE: The objective of this study was to evaluate the coherence between jaw and neck muscle activity during sleep bruxism. METHODS: In a cross-sectional observational design, the electromyographic activity of jaw (masseter, temporalis) and neck (sternocleidomastoid, trapezius) muscles in individuals with "definite" sleep bruxism was measured using ambulatory polysomnography (PSG). Coherence for masseter-temporalis, masseter-sternocleidomastoid and masseter-trapezius was measured during phasic and mixed rhythmic masticatory muscle activity episodes using coherence-analysing software. Outcome measures were as follows: presence or absence of significant coherence per episode (in percentages), frequency of peak coherence (FPC) per episode and sleep stage. RESULTS: A total of 632 episodes within 16 PSGs of eight individuals were analysed. Significant coherence was found between the jaw and neck muscles in 84.9% of the episodes. FPCs of masseter-temporalis were significantly positively correlated with those of masseter-sternocleidomastoid or masseter-trapezius (P < .001). Sleep stages did not significantly influence coherence of these muscular couples. CONCLUSION: During sleep bruxism, jaw and neck muscle activation is significantly coherent. Coherence occurs independently of sleep stage. These results support the hypothesis of bruxism being a centrally regulated phenomenon.

Speech changes in patients with a full rehabilitation for severe tooth wear, a first evaluation study.

OBJECTIVE: The aim of this study was to evaluate changes in speech characteristics and self-perceived quality of speech in tooth wear patients, after occlusal rehabilitation. MATERIALS AND METHODS: Patients with tooth wear were included in this study after informed consent. The amount of tooth wear was scored with Tooth Wear Evaluation System (TWES). To assess the perspective of the patient, the Dutch Speech Handicap Index was used (SHI). Acoustic analysis was performed to evaluate changes with the use of voice recordings. These were made before treatment, T0; directly after treatment, T1; 1 month after treatment, T2. With the use of PRAAT software, the spectral characteristic centre of gravity (COG) was evaluated for the sounds /s/, /f/, /v/, /d/, /t/, /m/. RESULTS: Recordings of 17 patients (14 men, 3 women, mean age 41.2 ± 10.4 years) were included. SHI scores did not change significantly between T0 and T2 (p = 0.054). A multiple regression model showed that for all sounds the intercept was negative, but statistically significant only for /s/ and /f/ between T0 and T1. The effect of the initial change (between T0 and T1) on the change between T1 and T2 was clearly negative for all sounds (p < 0.001), showing a rebound effect ranging between 29 and 68% of the initial change. CONCLUSION: Tooth wear patients perceive improvement in speech function after treatment. CLINICAL SIGNIFICANCE: Clinicians may explain to patients that speech is likely to alter for a short period due to treatment but that there will be a good adaption to the new situation.

Impact of restorative treatment of tooth wear upon masticatory performance.

OBJECTIVE: The restorative treatment of generalized tooth wear involves an increase in vertical dimension of occlusion and a comprehensive alteration of occlusal morphology. The aim of this study was to assess the impact of a direct adhesive restorative treatment on masticatory performance parameters. MATERIALS AND METHODS: A sample of 23 fully dentate adult generalized tooth wear patients (17 male, 6 female, age 41.7 ±â€¯8.3 years) undergoing direct composite restorative treatment was selected. Before and one month after restorative treatment with resin bonded composite restorations, masticatory performance was evaluated using 1) a comminution test, 2) a maximum voluntary bite force recording and 3) the sum score of five items related to eating and chewing from the Oral Health Impact Profile (OHIP-49) questionnaire. Statistical analysis was performed using a paired t-test, and analysis per OHIP item was done by a McNemar test (p < 0.05). RESULTS: There was no statistically significant difference in median particle size (X50) calculated before and after treatment (4.19 ±â€¯0.97 and 4.03 ±â€¯0.76, respectively, p = 0.327). Maximum voluntary bite force decreased significantly after treatment (baseline 389 ±â€¯90 N, one month recall 323 ±â€¯173 N, p = 0.028). The sum score of the five OHIP items significantly decreased after treatment (baseline 10.6 ±â€¯4.8, one month recall 6.6 ±â€¯2.5, p = 0.001), with the item regarding unsatisfactory diet showing the largest significance (p = 0.029). CONCLUSIONS: This study indicates that the restorative treatment of generalized tooth wear using direct resin bonded composite has no significant short-term effect on masticatory performance as measured with a comminution test, although the self-reported ability to eat and chew, as measured by the sum score of all pertaining OHIP items, did significantly improve. CLINICAL SIGNIFICANCE: On individual level, food comminution could be influenced by restorative treatment with increase of vertical dimension of occlusion, but at group level no significant effect is observed. Nevertheless, tooth wear patients do perceive improved ability to eat and chew foods, which is clinically relevant.

Association between self-reported bruxism and anger and frustration.

BACKGROUND: Even though bruxism has been shown to be associated with several psychological factors, few studies have been performed on its relationships with anger and frustration. OBJECTIVE: This study aimed to determine the association between self-reported awake and sleep bruxism and anger and frustration. METHODS: In this longitudinal observational study, 55 healthy adult participants with "possible" bruxism reported their experienced level of bruxism and several psychosocial factors and lifestyle factors for 28 consecutive days using a personal logbook. The logbook consisted of a daily diary and a weekly questionnaire composed of Dutch versions of validated questionnaires. The primary outcome data were analysed using multiple regression models. RESULTS: An increase in SB of 1 unit (on a scale ranging from 1 to 10) was associated with an increase in the anger-scale of 0.03 units, and the frustration-scale of 0.04 units. However, the random intercepts were 0.22 for anger and 0.19 for frustration, meaning that there were major differences between individuals. For awake bruxism (AB), the effects were an increase of 0.04 for anger with a random intercept of 0.21 and an increase of 0.03 for frustration with a random intercept of 0.06. The effects of anger and frustration on both SB and AB were not statistically significant. CONCLUSION: The association between anger and frustration and self-reported bruxism is small on group level. In individual cases, anger and frustration and self-reported bruxism may be co-existent.

Impact of tooth wear on masticatory performance.

OBJECTIVE: Masticatory performance is influenced by a number of variables such as age, gender, bite force, and occlusal units. Tooth wear may also play a role due to changes in occlusal area and in vertical dimension of occlusion. The aim of this study was to evaluate the effect of tooth wear on masticatory performance, using a communition test. MATERIALS AND METHODS: Patients with different degrees of tooth wear, referred by their general dental practitioners, and included in the Radboud Tooth Wear Project, were approached for this study and included after informed consent. The amount of post canine wear was scored with the Tooth Wear Index (TWI). The number of occluding posterior units was quantified and the bite force was measured using a transducer. Masticatory performance was measured with a communition test, with the median particle size (X50) after 20 chewing cycles as outcome measure. A multiple regression model was used to assess the relation between TWI, age, gender, bite force, occlusal units and X50. RESULTS: 52 participants (40 male, 12 female, mean age: 40 ±â€¯8.2y) were included in the study. The post canine TWI-score was between 1.0-3.3. The average number of occlusal units per participant was 11.9 ±â€¯1.4 and the mean bite force 369 ±â€¯172 N. The mean X50 was 4.2 ±â€¯1.1. The results showed no significant relation between post canine TWI-score, age, gender, bite force, and occlusal units upon the X50 (p > 0.13). CONCLUSION: This study showed that the degree of tooth wear could not be observed to have an effect on masticatory performance. CLINICAL SIGNIFICANCE: On individual level an effect could be present but looking at a larger group of patients, the degree of tooth wear did not have a relation with masticatory performance as measured with a communition test.

Masticatory muscle stretching for the management of sleep bruxism: A randomised controlled trial.

BACKGROUND: Sleep bruxism is a phenomenon associated with masticatory muscle hyperactivity. While stretching of limb and trunk muscles has been extensively studied for musculoskeletal disorders, little is known about the effectiveness of stretching of masticatory muscles in the management of bruxism. OBJECTIVE: The aim of this study is to determine the effectiveness of stretching of the masticatory muscles for sleep bruxism. METHODS: Twenty four pain-free individuals with sleep bruxism were randomly assigned to either an intervention group or a control group. Both groups were given sleep hygiene advice and the intervention group additionally received muscle-stretching exercises for 10 days. Primary outcome measures, bruxism bursts and episodes per hour of sleep, were measured by ambulant polysomnography. Secondary outcome measures were among others pain-free active maximum mouth opening (MMO) and masseter pressure pain threshold (PPT). RESULTS: The number of bruxism episodes per hour of sleep increased more in the intervention group than in the control group (by 1.1 episodes, P = 0.066), as did the number of bruxism bursts per hour of sleep (by 8.6 bursts, P = 0.049). MMO and PPT increased significantly more in the intervention group (by 3.2 mm, P = 0.020; and by 1.0 kg/cm2 , P = 0.036, respectively). CONCLUSION: Static stretching of the masticatory muscles resulted in a minor increase in sleep bruxism episodes (not significant) and bursts (significant). It also led to a significant increase in MMO and PPT. Therefore, masticatory muscle stretching was not effective in reducing sleep bruxism in the absence of pain and/or dysfunction.

A Retrospective Study on Possible Predictive Factors for Long-term Temporomandibular Joint Degeneration and Impaired Mobility in Juvenile Arthritis Patients.

AIMS: To determine possible predictive factors for long-term temporomandibular joint (TMJ) degeneration and dysfunction in juvenile idiopathic arthritis (JIA) patients. METHODS: A total of 94 patients (77% female) who had received a JIA diagnosis in an outpatient rheumatology clinic from 1993 to 1994 at a mean ± standard deviation age of 8.3 ± 4.53 years were included in the study. At inclusion, TMJ status regarding condylar degeneration was assessed orthopantomographically and given a Rohlin and Petersson score of 0 or ≥ 1. The maximal mouth opening (MMO) was also measured. Data on possible predictors were gathered retrospectively from the consultation at intake: gender, age at JIA onset, JIA subtype, physical limitations (ie, a Steinbrocker classification score of 0 or ≥ 1), human leukocyte antigen-B27, and antinuclear and rheumatoid factors. Disease duration and medication type were also considered. Associations between all of these factors and long-term condylar degeneration and MMO were assessed by using single and multiple regression analyses. RESULTS: Long-term TMJ degeneration and smaller MMO were both associated with younger age at JIA onset (P = .01; P = .03) and longer disease duration (P = .05; P = .002). Moreover, MMO was negatively associated with physical limitations at intake (P = .04). CONCLUSION: Within the limitations of this retrospective study design, these results suggest that young JIA patients with early physical limitations and prolonged disease are at risk of long-term TMJ degeneration and impaired mobility.

Bruxism: Is There an Indication for Muscle-Stretching Exercises?

Bruxism is a common phenomenon involving repetitive activation of the masticatory muscles. Muscle-stretching exercises are a recommended part of several international guidelines for musculoskeletal disorders and may be effective in management of the jaw muscle activity that gives rise to bruxism. However, most studies of muscle-stretching exercises have mainly focused on their influence on performance (eg, range of motion, coordination, and muscle strength) of the limb or trunk muscles of healthy individuals or individuals with sports-related injuries. Very few have investigated stretching of the human masticatory muscles and none muscle-stretching exercises in the management of (sleep) bruxism. This article reviews the literature on muscle-stretching exercises and their potential role in the management of sleep bruxism or its consequences in the musculoskeletal system.