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.

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 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.

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.

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.

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.

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.

Mandibular dysfunction as a reflection of bulbar involvement in SMA type 2 and 3.

OBJECTIVE: In a cross-sectional study, we aimed to determine (1) the effect of spinal muscular atrophy (SMA) type 2 and 3 on mandibular function reflected as masticatory performance, mandibular range of motion, and bite force and (2) the predictors of mandibular dysfunction. METHODS: Sixty patients with SMA type 2 and 3 (mean age 32.3 years, SD 17.4 years) and 60 age-matched controls filled out questionnaires about impairments of mandibular function. All participants underwent detailed clinical examination to document the mandibular range of motion including maximal mouth opening, bite force, and masticatory function. RESULTS: All mandibular movements, including mouth opening, lateral range of motion, and protrusion of the mandible, were reduced in patients with SMA type 2 and 3 compared to healthy controls (p < 0.001). Maximal bite force was 19% lower in patients than controls, and more in patients with SMA type 2 than type 3. The strongest predictive factor was SMA type for impairment of mandibular range of motion (R(2) = 0.82) and weakness of neck muscles for bite force (R(2) = 0.47). CONCLUSIONS: Reduced mandibular mobility and bite force are common complications in SMA. SMA type and neck muscle strength are important correlates of these complications. We provide further evidence for clinically relevant bulbar involvement in patients with SMA.

Fighting Against Disuse of the Masticatory System in Duchenne Muscular Dystrophy: A Pilot Study Using Chewing Gum.

Duchenne muscular dystrophy patients report masticatory problems. The aim was to determine the efficacy of mastication training in Duchenne muscular dystrophy using chewing gum for 4 weeks. In all, 17 patients and 17 healthy age-matched males participated. The masticatory performance was assessed using a mixing ability test and measuring anterior bite force before, shortly after and 1 month after the training. In the patient group the masticatory performance improved and remained after 1-month follow-up, no significant changes in anterior maximum bite force was observed after mastication training. In the healthy subject the bite force increased and remained at the 1-month follow-up; no significant differences in masticatory performance were observed. Mastication training by using sugar-free chewing gum in Duchenne muscular dystrophy patients improved their masticatory performance. Since bite force did not improve, the working mechanism of the improvement in chewing may relate to changes of the neuromuscular function and coordination, resulting in improvement of skills in performing mastication.

Bulbar muscle MRI changes in patients with SMA with reduced mouth opening and dysphagia.

OBJECTIVE: We performed a study in patients with proximal spinal muscular atrophy (SMA) to determine the prevalence of reduced maximal mouth opening (MMO) and its association with dysphagia as a reflection of bulbar dysfunction and visualized the underlying mechanisms using MRI. METHODS: We performed a cross-sectional study of MMO in 145 patients with SMA types 1-4 and 119 healthy controls and used MRI in 12 patients to visualize mandibular condylar shape and sliding and the anatomy of muscle groups relevant for mouth opening and closing. We analyzed associations of reduced MMO with SMA severity and complaints of dysphagia. RESULTS: Reduced MMO was defined as an interincisal distance ≤ 35 mm and was found in none of the healthy controls and in 100%, 79%, 50%, and 7% of patients with SMA types 1, 2, 3a, and 3b/4, respectively. MRI showed severe fatty degeneration of the lateral pterygoid muscles that mediate mouth opening by allowing mandibular condylar sliding but relatively mild involvement of the mouth closing muscles in patients with reduced MMO. Reduced MMO was associated with SMA type, age, muscle weakness, and dysphagia (p < 0.05). CONCLUSIONS: Reduced MMO is common in SMA types 1-3a and is mainly caused by fatty degeneration of specific mouth opening muscles. Reduced MMO is a sign of bulbar dysfunction in SMA.

Risk factors for anterior disc displacement with reduction and intermittent locking in adolescents.

AIMS: To test the hypothesis that oral parafunctions and symptomatic temporomandibulair joint (TMJ) hypermobility are risk factors in adolescents for both anterior disc displacement with reduction (ADDR) and intermittent locking. METHODS: Participants were two hundred sixty 12- to 16-year-old adolescents (52.3% female) visiting a university clinic for regular dental care. ADDR and symptomatic TMJ hypermobility were diagnosed using a structured clinical examination. During the anamnesis, reports of intermittent locking and of several parafunctions were noted, eg, nocturnal tooth grinding, diurnal jaw clenching, gum chewing, nail biting, lip and/or cheek biting, and biting on objects. The adolescents' dentitions were examined for opposing matching tooth-wear facets as signs of tooth grinding. Risk factors for ADDR and intermittent locking were first assessed using univariate logistic regression and then entered into a stepwise backward multiple model. RESULTS: While in the multiple model, ADDR was weakly associated only with increasing age (P = .02, explained variance 8.1%), intermittent locking was weakly correlated to diurnal jaw clenching (P = .05, explained variance 27.3%). CONCLUSION: In adolescence, diurnal clenching may be a risk factor for intermittent locking while age may be a risk factor for ADDR. Symptomatic TMJ hypermobility seems to be unrelated to either ADDR or to intermittent locking.