Parkinson's disease, temporomandibular disorders and bruxism: A pilot study

The relationship between possible, probable, or definite sleep bruxism and sleep quality: A systematic review

It has been suggested that sleep bruxism may interrupt sleep continuity, hence potentially influencing sleep quality. The aim of this study was to systematically review the relationship between possible, probable, and definite sleep bruxism and sleep quality in otherwise healthy individuals. A systematic search on sleep bruxism and sleep quality was performed in seven databases until 19 December 2022. Eligible articles were screened, and quality assessment was performed via the Joanna Briggs Institute Scale. Of 3681 articles screened, 13 were included in this study. Of these, six evaluated the relationship between sleep quality and possible sleep bruxism, three with probable sleep bruxism, and four with definite sleep bruxism. An association between poor sleep quality and sleep bruxism was found among those individuals diagnosed with possible and probable sleep bruxism. However, the studies conducted in individuals with definite sleep bruxism failed to demonstrate any association. With more reliable measures to evaluate sleep bruxism, a relationship between sleep bruxism and sleep quality was not evident.

Association between pain threshold and manifested pain assessed using a PD-specific pain scale in Parkinson's disease

Background

The neurodegenerative process in Parkinson's disease (PD) affects both dopaminergic and non-dopaminergic structures, which determine the wide range of motor and non-motor symptoms (NMS), including different types of pain. Diverse mechanisms contribute to pain in PD. Abnormal nociceptive processing is considered a distinctive feature of the disease.

Objective

In the present study, we used a validated PD-specific pain assessment tool to investigate self-reported pain in PD patients and to analyze the association with the objective pain threshold.

Methods

The RIII component of the nociceptive flexor reflex was assessed in 35 patients with PD and was compared to 40 healthy controls. Self-reported pain was measured using the Bulgarian version of the King's Parkinson's Disease Pain Scale (KPPS-BG). A correlation analysis was used to investigate the relationship between the objective nociceptive threshold and PD pain as assessed by KPPS-BG.

Results

PD patients had a significantly lower RIII threshold than control individuals (the mean SD value was 6.24 ± 1.39 vs. 10.33 ± 1.64) when assessed in the "off" state. A statistically significant (p < 0.05) fairly negative Spearman's correlation was observed between the decreased spinal nociceptive threshold and fluctuation-related pain (-0.31). Domain 4, "nocturnal pain" (-0.21), and the KPPS-BG total score (-0.21) showed a weak negative correlation. An insignificant positive correlation was found between domain 6-"discoloration, edema/swelling"-and the RIII threshold. A higher Movement Disorders Society Unified Parkinson's Disease Rating Scale (MDS-UPDRS) part III score and modified Hoehn and Yahr (H&Y) scale are associated with a decreased nociceptive flexor reflex threshold.

Conclusion

The results of the present study demonstrate the important role of increased spinal nociception in the occurrence of pain, which is associated with fluctuations and, to a lesser extent, nocturnal pain.

Sleep Bruxism and Obstructive Sleep Apnea Are Not Risk Factors for Tension-Type Headache (TTH): A Polysomnographic Study

Background: Tension-type headache (TTH) is the most common primary headache. Obstructive sleep apnea (OSA) and sleep bruxism (SB) are two of the most common sleep disorders; however, the relationship between TTH, OSA, and SB has not been conclusively proved in the literature. The objective of our study was to estimate potential associations with OSA and SB in TTH subjects. Methods: 108 adult individuals who underwent polysomnography (vPSG) were included, and the group was divided into two subgroups: TTH (n = 34) and control (n = 74). The International Classification of Headache Disorders (ICHD-3) guidelines were used to diagnose TTH. OSA and SB diagnoses were based on vPSG examination with electromyographic (EMG) recordings and the American Academy of Sleep Medicine (AASM) criteria. The results were analyzed, where p < 0.05 was considered to be statistically significant. Results: In the TTH group, the incidence of SB was more than two times lower than the control (OR = 0.41, 95% CI: 0.17-0.96, p < 0.05). However, the incidence of severe SB (BEI > 4) was similar in the TTH and control groups (OR = 0.54, 95% CI: 0.21-1.35, p > 0.05). Additionally, phasic and tonic SB episodes were less frequent in the TTH group compared to the controls (p < 0.05). The mean apnea-hypopnea index (AHI) was not significantly different between the TTH and control groups (p > 0.05). The sleep architecture and respiratory disturbances did not differ between the examined groups (p > 0.05). Conclusions: SB is not a risk factor for TTH. Moreover, severe SB is not connected with TTH. OSA is not a risk factor for TTH. Sleep quality did not differ between both groups during PSG; therefore, TTH may not change sleep structure. The mechanism of these findings is still unclear, and further studies should explain in detail the association between TTH and OSA.

Relationship between Sleep Bruxism Determined by Non-Instrumental and Instrumental Approaches and Psychometric Variables

Sleep bruxism (SB) can be determined with different diagnostic procedures. The relationship between psychometric variables and SB varies depending on the diagnostic method. The aim of the study was to compare the association between SB and oral health-related quality of life (OHRQoL; measured by the Oral Health Impact Profile, OHIP), anxiety (measured by the State-Trait anxiety inventory, STAI), and stress (single scale variable) depending on the diagnostic method in the same sample. N = 45 participants were examined by non-instrumental (possible/probable SB) and instrumental methods (definite SB). The OHIP differed significantly between possible SB (median = 4) and non-SB (median = 0) with W = 115, p = 0.01, and probable SB (median = 6) and non-SB (median = 0) with W = 101, p = 0.01). There was no significant difference in the OHIP score between definite SB and non-SB. For the other psychometric variables, the analyses revealed no significant differences between SB and non-SB in all diagnostic procedures. The results suggest that there is a difference between possible/probable and definite SB with respect to the association with OHRQoL. Certain aspects of possible/probable SB might be responsible for the poor OHRQoL, which are not measured in definite SB.

Sleep bruxism: The past, the present, and the future-evolution of a concept

BACKGROUND

The concept of sleep bruxism (SB) has evolved exponentially over the past several decades. Many theories and hypotheses have been proposed as to the definition, pathophysiology, and management of SB, from the early 1960s through the present. The role of peripheral factors, such as dental occlusion, in the pathogenesis of SB has been discarded.

TYPES OF STUDIES REVIEWED

The authors searched several electronic databases (ie, PubMed, Google Scholar, Web of Science, Embase, and Ovid MEDLINE) for studies on bruxism. The search was conducted from January 1961 through May 2023 and yielded 4,612 articles, of which 312 were selected for comprehensive review after eliminating duplicates and nonfocused articles.

RESULTS

There has been an evident progressive shift from the role of peripheral factors, such as dental occlusion, to more central factors, such as the involvement of a central pattern generator as well as the autonomic nervous system, in the genesis of bruxing movements. There is continued robust interest in the dental community to elucidate the contributing factors involved in SB.

CONCLUSIONS AND PRACTICAL IMPLICATIONS

The neurophysiology of SB appears to be leaning more toward central rather than peripheral factors. There is increasing evidence of the role of the autonomic nervous system, genetics, and comorbidities in the genesis of SB. The scientific literature seems to refute the role of dental occlusion in the causation of bruxing movements. As per the literature, there has been a paradigm shift in the definition and genesis of SB and its possible dental implications and management, which also highlights the need for succinct scientific studies in this regard.

Oral health experiences of people living with Parkinson's disease: a scoping review

Background and aim Parkinson's disease is the fastest growing and second most common progressive neurodegenerative condition in the UK; poised to represent a major societal and health care challenge. The scoping review aims to provide an overview of the literature on the oral health (OH) experiences of people living with Parkinson's, identifying current research gaps and future priorities.Method Search strategies included three electronic databases, two grey literature databases, relevant organisations, specialist journals and hand searching of the reference lists. A data extraction tool was developed and piloted.Results A total of 121 items were included in the review. Four themes were identified: OH impact, education and training, service delivery and wider impacts of OH for people with Parkinson's (PwP). The majority of studies included were cross-sectional in design, describing the OH status of PwP.Conclusion The majority of research to date has focused on OH impact. Areas for future research include use of qualitative studies exploring the experiences, attitudes and priorities of PwP and their care partners. Inclusion of medical, dental and allied health care professionals, together with people with lived experience, is required to develop, implement and evaluate interventions to support OH.

Association between Psychological Distress and Possible, Probable, and Definite Sleep Bruxism-A Comparison of Approved Diagnostic Procedures

(1) Background: The relationship between sleep bruxism (SB) and psychological distress has been investigated in numerous studies and is heterogeneous. Different diagnostic procedures have been applied to determine SB. The aim of this study was to directly compare the association between psychological distress and SB diagnosed by different accepted methods. (2) Methods: Data of N = 45 subjects were analyzed, including group comparisons and correlation analyses. Following diagnostic methods for the determination of SB were used in one sample: self-report, clinical assessment, polysomnography with audio-video recording and a novel diagnostic sheet with analyzing software. Psychological distress was measured using the global severity index (GSI) of the Symptom Checklist-90-Standard (SCL-90-S). (3) Results: The GSI did not differ significantly between subjects with and without SB, regardless of the underlying diagnostic classification (p > 0.05). In-depth correlation analyses of self-report and clinical data revealed a weak-to-medium correlation with the GSI (r = 0.12-0.44). Due to non-normally distributed data, a test of statistical significance was not possible. Variables of instrumental methods such as the SB index (amount of SB activity per hour) of polysomnography (PSG) showed almost no correlation with psychological distress (r = -0.06-0.05). (4) Conclusions: Despite these limitations, the results provide an indication that the choice of diagnostic procedure may elucidate the variance in the correlation between SB and psychological distress.

Secondary bruxism: A valid diagnosis or just a coincidental finding of additional masticatory muscle activity? A narrative review of literature

INTRODUCTION

Bruxism is defined as a repetitive masticatory muscle activity that can manifest it upon awakening (awake bruxism-AB) or during sleep (sleep bruxism-SB). Some forms of both, AB and SB can be associated to many other coexistent factors, considered of risk for the initiation and maintenance of the bruxism. Although controversial, the term 'secondary bruxism' has frequently been used to label these cases. The absence of an adequate definition of bruxism, the non-distinction between the circadian manifestations and the report of many different measurement techniques, however, are important factors to be considered when judging the literature findings. The use (and abuse) of drugs, caffeine, nicotine, alcohol and psychoactive substances, the presence of respiratory disorders during sleep, gastroesophageal reflux disorders and movement, neurological and psychiatric disorders are among these factors. The scarcity of controlled studies and the complexity and interactions among all aforementioned factors, unfortunately, does not allow to establish any causality or temporal association with SB and AB. The supposition that variables are related depends on different parameters, not clearly demonstrated in the available studies.

OBJECTIVES

This narrative review aims at providing oral health care professionals with an update on the co-risk factors and disorders possibly associated with bruxism. In addition, the authors discuss the appropriateness of the term 'secondary bruxism' as a valid diagnostic category based on the available evidence.

CONCLUSION

The absence of an adequate definition of bruxism, the non-distinction between the circadian manifestations and the report of many different measurement techniques found in many studies preclude any solid and convincing conclusion on the existence of the 'secondary' bruxism.

Evaluation of Temporomandibular Joint in Patients with Parkinson's Disease: A Comparative Study

(1) The aim of this study was to perform an evaluation of the temporomandibular joint (TMJ) in patients with Parkinson's disease (PD) and present the morphological differences of the TMJ between healthy subjects and patients with PD. (2) A total of 102 Caucasian subjects were divided equally into two groups. The study group consisted of patients with PD, while the control group comprised healthy subjects. Ten parameters, including anterior joint space (AJS), superior joint space (SJS), posterior joint space (PJS), condyle head length (CHL), condylar neck width (CNW), minor axis of the condyle (MAC), long axis of the condyle (LAC), condylar axis inclination (CI), medial joint space (MJS), and lateral joint space (LJS), were measured using magnetic resonance images. The data were statistically analyzed using paired samples t-test and Student's t-test, with a significance level set at p < 0.05. (3) In the PD group, all TMJ parameters showed a statistically significant difference between both sides of the face (p < 0.05). However, in the control group, AJS, SJS, PJS, CHL, CNW, MAC, CI, MJS, and LJS did not show a statistically significant difference between both sides of the face (p > 0.05), except for LAC (p < 0.05). The asymmetry index values of AJS, SJS, PJS, CHL, CNW, MAC, CI, MJS, and LJS demonstrated a statistically significant difference between the study and control groups (p < 0.05), except for LAC (p > 0.05). (4) Within the limitations of this retrospective study, the findings suggest that TMJ morphology and asymmetry could be associated with PD.

Orofacial function and temporomandibular disorders in Parkinson's Disease: a case-controlled study

BACKGROUND

The difficulties and challenges faced by people with Parkinson's disease (PD) in performing daily orofacial function are not systematically investigated. In this study, specific orofacial non-motor and motor symptoms and functions were systematically examined in PD patients in comparison to a matched control group.

METHODS

The clinical case-controlled study was conducted from May 2021 to October 2022 and included persons with PD and age- and gender-matched persons without PD. The participants with PD were outpatients diagnosed with PD at the Department of Neurology at Bispebjerg University Hospital in Copenhagen, Denmark. The participants underwent a systematic clinical and relevant self-assessment of the orofacial function and temporomandibular disorders (TMD). The primary outcomes were objective and subjective assessments of the general orofacial function, mastication, swallowing, xerostomia and drooling. The secondary outcomes were the prevalence of TMD and orofacial pain. The difference in outcome measures between the two groups was analysed using chi-square and Mann-Whitney U test.

RESULTS

The study included 20 persons with PD and 20 age- and gender-matched persons without PD. Both objectively and subjectively, persons with PD had poorer orofacial function than the control group. Persons with PD had also a significantly more severe limitation of jaw mobility and jaw function. The objective masticatory function was also significantly reduced for persons with PD compared to the control group, and 60% of persons with PD found it difficult to eat foods with certain consistencies while 0% of the control group reported that problem. Persons with PD could swallow less water per second and the average swallowing event was significantly longer for PD persons. Even though PD persons reported more xerostomia (58% for persons with PD and 20% for control persons), they also reported significantly more drooling than the control group. Additionally, orofacial pain was more prevalent in PD persons.

CONCLUSIONS

Persons with PD have a compromised orofacial function. Furthermore, the study indicates a link between PD and orofacial pain. In order to screen and treat persons with PD accordingly, healthcare professionals should be aware of and address these limitations and symptoms.

TRIAL REGISTRATION

The trial was approved by the Regional Committee on Research Health Ethics of the Capital Region (H-20,047,464), the Danish Data Protection Agency (514 - 0510/20-3000), and registered at ClinicalTrials.gov (NCT05356845).

It Is Time for a Multidisciplinary Rehabilitation Approach: A Scoping Review on Stomatognathic Diseases in Neurological Disorders

Patients affected by neurological disorders can develop stomatognathic diseases (SD) related to decreased bite force and quality of mastication, bruxism, severe clicking and other temporomandibular disorders (TMD), which deeply affect patients' swallowing, masticatory and phonation functions and, therefore, their quality of life. The diagnosis is commonly based on medical history and physical examination, paying attention to the temporomandibular joint (TMJ) range of movements, jaw sounds and mandibular lateral deviation. Diagnostic tools such as computed tomography and magnetic resonance imaging are used instead in case of equivocal findings in the anamnesis and physical evaluation. However, stomatognathic and temporomandibular functional training has not been commonly adopted in hospital settings as part of formal neurorehabilitation. This review is aimed at describing the most frequent pathophysiological patterns of SD and TMD in patients affected by neurological disorders and their rehabilitative approach, giving some clinical suggestions about their conservative treatment. We have searched and reviewed evidence published in PubMed, Google Scholar, Scopus and Cochrane Library between 2010 and 2023. After a thorough screening, we have selected ten studies referring to pathophysiological patterns of SD/TMD and the conservative rehabilitative approach in neurological disorders. Given this, the current literature is still poor and unclear about the administration of these kinds of complementary and rehabilitative approaches in neurological patients suffering from SD and/or TMD.

Clinicians' view on the management of oral health in Parkinson's disease patients: a qualitative study

BACKGROUND

due to numerous motor and non-motor symptoms, dental treatment in patients with Parkinson's Disease (PD) can be challenging. Knowledge regarding optimal management of oral health in PD patients is lacking.

AIM

to gain a deeper understanding of the experiences of dentists regarding oral health care for PD patients in the Netherlands.

MATERIAL AND METHOD

semi-structured interviews were conducted with (specialized) dentists working with PD patients. A thematic analysis was performed using a framework-based approach.

RESULTS

ten dentists were interviewed. They reported that dental care in PD patients requires 1) adaptation of timing and length of treatments and consultations, and 2) intensifying preventive measures. Dentists experienced the organization as bureaucratic and difficult. Moreover, differences between being institutionalized or living at home were present. Education and research are needed to improve PD patients' oral health. The experience level and affinity for treating PD patients positively influences confidence levels of the practitioner. Finally, points of improvement were suggested.

CONCLUSION

managing oral health in PD patients is challenging, and interdisciplinary collaboration is needed to overcome difficulties. Reducing the bureaucratic burden and improving knowledge could help and stimulate oral health care providers to treat PD patients more effectively and, consequently, improve their oral health.

Parkinson's disease and oral health: A systematic review

OBJECTIVE

in patients with Parkinson's Disease (PD), oral health can be affected by motor and non-motor symptoms and/or medication use. Therefore, the aim was to systematically review the literature on oral health and associated factors of oral health in PD patients.

DESIGN

a literature search was performed from inception up to April 5th, 2023. Original studies that assessed oral health-related factors in PD patients and were written in English or Dutch, were included.

RESULTS

11276 articles were identified, of which 43 met the inclusion criteria (quality range poor-good). A higher prevalence of dental biofilm, bleeding/gingivitis, pocket depth (≥4 mm), tooth mobility, caries, and number of decayed missing filled teeth/surfaces was found in PD patients than in controls. However, no difference between both groups was found when analysing edentulism and wearing dentures. Poor oral health of PD patients was associated with a longer disease duration, higher disease severity, and more prescribed medications.

CONCLUSIONS

oral health of PD patients is worse than that of healthy individuals. It is associated with the duration and severity of PD and medication use. Therefore, we advise regular appointments with oral health care professionals, with an important focus on prevention.

Orofacial pain and dysfunction in patients with Parkinson's disease: A scoping review

BACKGROUND

Parkinson's disease (PD) is commonly known as a disorder that affects the smooth performance of body movements. In addition to the motor impairments, patients with PD often experience pain. Both motor impairments and pain can occur throughout the body, hence including the orofacial region. However, currently, there is a lack of knowledge on the orofacial manifestations. Since orofacial pain and dysfunction can, amongst others, reduce the quality of life of patients with PD, it is important to explore the prevalence of these symptoms in the PD population.

OBJECTIVE

To provide a broad overview of the relevant literature on orofacial pain and dysfunction in patients with PD. Furthermore, we aim to generate hypotheses for future research on this topic.

DATABASES AND DATA TREATMENT

A literature search (in PubMed, Embase.com, Web of Science [Core collection], and Cochrane Library) was performed on 20 January 2022, in collaboration with a medical librarian. In total, 7180 articles were found, of which 50 were finally included in this scoping review.

RESULTS

In the included studies, pain (e.g. orofacial pain (N = 2) and temporomandibular disorder pain (N = 2)), orofacial motor dysfunction (e.g. limited jaw movements (N = 10), reduced maximum muscle output (N = 3), chewing difficulties (N = 9), unspecified TMD (N = 3), sensory disturbances (N = 1)), and bruxism (N = 3) were observed more often in patients with PD than in healthy controls.

CONCLUSION

Patients with PD experience more pain in the orofacial area and more dysfunction of the masticatory system than their healthy peers.

SIGNIFICANCE

This scoping review can increase health care providers' awareness of the problems that can be encountered in the orofacial area of PD patients, especially pain syndromes also occur in the orofacial region and not only in the extremities. Besides, dysfunction of the orofacial area is elaborated in this scoping review, which helps to understand that this limits PD patients' quality of life. Further, the outcomes of this scoping review can assist in encouraging collaboration between medicine and dentistry. Finally, this scoping review suggests new research areas, based on the gaps identified in the current literature on this topic. Ultimately, this will improve individualized strategies for reducing orofacial pain and/or dysfunction in PD patients.

Parkinson's disease, temporomandibular disorder pain and bruxism and its clinical consequences: a protocol of a single-centre observational outpatient study

INTRODUCTION

A recent questionnaire-based study suggested that bruxism and painful temporomandibular disorders (TMD pain) may be more prevalent in patients with Parkinson's disease (PD) compared with controls. The presence of both bruxism and TMD pain may negatively influence patients' quality of life. The present study is designed to clinically and more objectively investigate the presence of bruxism and TMD pain in patients with PD. The secondary aim of the study is to identify factors associated with bruxism and TMD pain in patients with PD, such as disease severity and dopaminergic medication usage. Furthermore, the presence of tooth wear in patients with PD will be studied as this can be a major consequence of bruxism. Finally, deviations in saliva composition that may contribute to tooth wear will be studied.

METHODS AND ANALYSIS

This is a single-centre observational outpatient study at the Amsterdam University Medical Centres, location VUmc. All patients with a clinical diagnosis of PD will be eligible for inclusion. Participants will fill in a set of questionnaires. Subsequently, patients will be examined clinically for, among others, TMD pain, presence and severity of tooth wear, and deviations in saliva composition. Sleep-time registrations will take place for 5 nights with the GrindCare GC4 (ie, a portable, single-channel electromyographic recorder) to assess sleep bruxism and simultaneously by the use of the BruxApp for 5 days to assess awake bruxism. We will partly use data collected during standard clinical care to minimise patient burden.

ETHICS AND DISSEMINATION

The scientific and ethical aspects of this study protocol have been approved by the Medical Ethics Review Committee of the Amsterdam UMC, location VUmc; NL. 2019.143. Informed consent will be obtained from all participants. The results will be published in a peer-reviewed journal, if relevant presented at conferences, and published as part of a PhD thesis.

TRIAL REGISTRATION NUMBER

NL8307.

Oral health-related quality of life in patients with Parkinson's disease

Background

Parkinson's disease (PD) is a neurodegenerative condition affecting the quality of life. Due to a worsening of oral health in PD patients with the progression of the disease, oral health‐related quality of life (OHRQoL) could be impaired as well.

Objectives

To assess whether PD patients in The Netherlands experience worse OHRQoL than historical controls, and to investigate which factors are associated with OHRQoL in PD patients.

Materials & Methods

In total, 341 PD patients (65.5 ± 8.4 years) and 411 historical controls (62.6 ± 5.3 years) participated. Both groups completed a questionnaire. The PD patients were asked questions regarding demographics, PD, oral health, and OHRQoL. The historical controls filled in demographic information and questions regarding OHRQoL. The latter construct was assessed using the Dutch 14‐item version of the Oral Health Impact Profile (OHIP‐14). Data were analysed using independent samples t‐tests and univariate and multivariate linear regression analysis.

Results

The mean OHIP‐14 score was higher in PD patients (19.1 ± 6.7) than in historical controls (16.5 ± 4.4) (t(239) = 6.5; p < .001). OHRQoL in PD patients was statistically significant associated with motor aspects of experiences of daily living (B = 0.31; t(315) = 7.03; p < .001), worsening of the oral environment during disease course (B = 3.39; t(315) = 4.21; p < .001), being dentate (B = −5.60; t(315) = −4.5; p < .001), tooth wear (B = 2.25; t(315) = 3.29; p = .001), and possible burning mouth syndrome (B = 5.87; t(315) = 2.87; p = .004).

Conclusion

PD patients had a lower OHRQoL than historical controls. Besides, PD‐related variables and oral health‐related variables were associated with OHRQoL.

Associations between sleep bruxism and other sleep-related disorders in adults: a systematic review

OBJECTIVE

Systematic reviews on sleep bruxism (SB) as a comorbid condition of other sleep-related disorders are lacking. Such reviews would contribute to the insight of sleep clinicians into the occurrence of SB in patients with other sleep-related disorders, and into the underlying mechanisms of such comorbid associations. This systematic review aimed: 1. to determine the prevalence of SB in adults with other sleep-related disorders; and 2. to determine the associations between SB and other sleep-related disorders, and to explain the underlying mechanisms of these associations.

METHODS

A systematic search on SB and sleep-related disorders was performed in PubMed, Embase, Cochrane Library, and Web of Science to identify eligible studies published until May 15, 2020. Quality assessment was performed using the Risk of Bias Assessment tool for Non-randomized Studies.

RESULTS

Of the 1539 unique retrieved studies, 37 articles were included in this systematic review. The prevalence of SB in adult patients with obstructive sleep apnea, restless leg syndrome, periodic limb movement during sleep, sleep-related gastroesophageal reflux disease, REM behavior disorder (RBD), and sleep-related epilepsy was higher than that in the general population. The specific mechanisms behind these positive associations could not be identified.

CONCLUSIONS

SB is more prevalent in patients with the previously mentioned disorders than in the general population. Sleep arousal may be a common factor with which all the identified disorders are associated, except RBD and Parkinson's disease. The associations between SB and these identified sleep-related disorders call for more SB screening in patients with the abovementioned sleep-related disorders.

Tooth Wear Evaluation System (TWES) 2.0-Reliability of diagnosis with and without computer-assisted evaluation

BACKGROUND

Tooth wear is a multifactorial process, leading to the loss of dental hard tissues. Therefore, it is important to detect the level of tooth wear at an early stage, so monitoring can be initiated. The Tooth Wear Evaluation System (TWES) enables such a multistage diagnosis of tooth wear. The further developed TWES 2.0 contains a complete taxonomy of tooth wear, but its reliability has not yet been validated.

OBJECTIVES

The aim of the study was to examine in a randomised controlled trial (RCT) whether diagnoses made based on the TWES 2.0 are reproducible and whether this reproducibility is also achieved with computer-assisted diagnostics.

METHODS

44 dental students received extensive training in TWES 2.0 assessment and taxonomy. The students each evaluated at least 10 (of the present 14) anonymised patient cases using gypsum models and high-resolution intra-oral photographs according to TWES 2.0. One half initially evaluated on paper; the other half used dedicated software (CMDfact / CMDbrux). After half of the patient cases (5), the evaluation methods were switched (AB/BA crossover design). The diagnoses were then evaluated for agreement with the predefined sample solution.

RESULTS

Evaluation of agreement with the sample solution according to Cohen's kappa indicated a value of 0.46 for manual (traditional) evaluation; and 0.44 for computer-assisted evaluation. Evaluation of agreement between examiners was 0.38 for manual and 0.48 for computer-assisted evaluation (Fleiss' kappa).

CONCLUSION

The results of this study proved that the taxonomy of the TWES 2.0 has acceptable reliability and can thus be used by dentists. Accordingly, the system can be learned quickly even by untrained practitioners. Comparable results are achieved with computer-assisted evaluation.

Oral Health Disorders in Parkinson's Disease: More than Meets the Eye

Despite clinical evidence of poor oral health and hygiene in Parkinson’s disease (PD) patients, the mouth is often overlooked by both patients and the medical community, who generally focus on motor or psychiatric disorders considered more burdensome. Yet, oral health is in a two-way relationship with overall health—a weakened status triggering a decline in the quality of life. Here, we aim at giving a comprehensive overview of oral health disorders in PD, while identifying their etiologies and consequences. The physical (abnormal posture, muscle tone, tremor, and dyskinesia), behavioral (cognitive and neuropsychiatric disorders), and iatrogenic patterns associated with PD have an overall detrimental effect on patients’ oral health, putting them at risk for other disorders (infections, aspiration, pain, malnutrition), reducing their quality of life and increasing their isolation (anxiety, depression, communication issues). Interdisciplinary cooperation for prevention, management and follow-up strategies need to be implemented at an early stage to maintain and improve patients’ overall comfort and condition. Recommendations for practice, including (non-)pharmacological management strategies are discussed, with an emphasis on the neurologists’ role. Of interest, the oral cavity may become a valuable tool for diagnosis and prognosis in the near future (biomarkers). This overlooked but critical issue requires further attention and interdisciplinary research.

Association between Temporomandibular Joint Disorder and Parkinson's Disease

This study performed two different analyses using a large set of population data from the Korean National Health Insurance Service Health Screening Cohort to evaluate the interactional association between temporomandibular disorder (TMD) and Parkinson’s disease (PD). Two nested case–control population-based studies were conducted on 514,866 participants. In Study I, 4455 participants with TMD were matched with 17,820 control participants, with a ratio of 1:4. In Study II, 6076 participants with PD were matched with 24,304 control participants, with a ratio of 1:4. Obesity, smoking, alcohol consumption, systolic, diastolic blood pressure, fasting blood glucose level, and total cholesterol were adjusted. The adjusted odds ratio (OR) for TMD was 1.43 (95% confidence interval (CI) = 1.02–2.00) in PD patients compared to non-PD patients in Study I (p < 0.001). The adjusted OR for PD was 1.56 (95% CI = 1.13–2.15) in TMD patients compared to non-TMD patients in Study II (p = 0.007). This study demonstrated that patients with TMD have a significantly higher risk of developing PD and, conversely, those with PD have a significantly higher risk of developing TMD.

Is dopaminergic medication dose associated with self-reported bruxism in Parkinson's disease? A cross-sectional, questionnaire-based study

OBJECTIVES

It is not clear whether dopaminergic medication influences bruxism behaviour in patients with Parkinson's disease (PD). Therefore, the aims are to investigate (i) the prevalence of possible (i.e., self-reported) bruxism (sleep and awake) in PD patients, and (ii) whether the use of dopaminergic medication and other factors (viz., demographic characteristics, PD-related factors, and possible consequences of bruxism) are associated with possible bruxism (sleep or awake).

MATERIALS AND METHODS

This study concerns a secondary analysis of an earlier published study. Three hundred ninety-five PD patients (67.9 ± 8.6 years of age; 58.7% males) were included. The levodopa equivalent daily dosage (LEDD) was used as a measure of the dopaminergic medication level. Subsequently, a logistic regression analysis was performed for the dependent variables 'awake bruxism' and 'sleep bruxism', with the following predictors: gender, age, LEDD, time since PD diagnosis, temporomandibular disorder (TMD) pain, jaw locks, and tooth wear.

RESULTS

The prevalence of possible awake and sleep bruxism was 46.0% and 24.3%, respectively. Awake bruxism was associated with sleep bruxism (OR = 8.52; 95% CI 3.56-20.40), TMD pain (OR = 4.51; 95% CI 2.31-8.79), and tooth wear (OR = 1.87; 95% CI 1.02-3.43). Sleep bruxism was associated with tooth wear (OR = 12.49; 95% CI 4.97-31.38) and awake bruxism (OR = 9.48; 95% CI 4.24-21.19). Dopaminergic medication dose was not associated with awake bruxism (OR = 1.0; 95% CI 0.99-1.00) or sleep bruxism (OR = 1.0; 95% CI 0.99-1.00).

CONCLUSION

Bruxism is a common condition in PD patients, but is not associated with the dopaminergic medication dose.

CLINICAL RELEVANCE

(Oral) health care providers should be alerted about the possibility of sleep and awake bruxism activity in PD patients, along with this activity's possible negative health outcomes (viz., TMD pain, tooth wear).

Sleep Disorders in Parkinson Disease

Sleep disorders in Parkinson disease have attracted the attention of clinicians and researchers for decades. Recently, major advances in their clinical characterization, polysomnographic description, pathophysiologic understanding, and treatment took place. Parkinson disease encompasses the whole spectrum of sleep medicine: every category of sleep disorder can be observed in these patients. Video polysomnography frequently is indicated, sometimes followed by multiple sleep latency/maintenance of wakefulness tests. Additional studies may include actigraphy, cardiorespiratory polygraphy, and dim light melatonin assessment. Treatment needs to be specific to the underlying sleep disorder and can include medications and nondrug treatments, for example, behavioral therapy and light therapy.

Orofacial pain in 1916 patients with early or moderate Parkinson disease

This article reports the largest epidemiological study of orofacial pain prevalence in patients with Parkinson disease to date.

Introduction:

Several studies have reported that some types of orofacial pain are more common in patients with Parkinson disease (PD) than the general population.

Objectives:

In this study, we aimed to investigate the prevalence of self-reported orofacial pain in a larger group of patients with PD than has been previously studied.

Methods:

We analysed data from 1916 participants with PD in a cross-sectional study recruited to the UK Parkinson's Pain Study who had detailed assessments of pain, motor, and nonmotor symptoms. The King's Parkinson's Pain scale was used to quantify different subtypes of pain.

Results:

A total of 139 (7.3%) patients reported the presence of some form of orofacial pain. Burning mouth syndrome was reported in 32 (1.7%), whereas chewing pain was found in 38 (2.0%) and grinding pain in 78 (4.0%). Orofacial pain was significantly more common in females (10.4%) than males (5.9%). Multiple logistic regression analysis showed a significant association between orofacial pain and pain severity, neuropathic pain, and oral motor and nonmotor dysfunction.

Conclusion:

In our study, population cohort of early patients with PD found prevalence of orofacial pain conditions similar to that in the general population.

Patient-based experiences with the use of an ambulatory electromyographic device for the assessment of masticatory muscle activity during sleep

Background

It is important to know how easy or difficult it is to use an ambulatory electromyographic (EMG) device for sleep bruxism assessment, and how this might affect its future utilisation.

Objective

To explore the experience of individuals using an EMG device that pairs with a smartphone app, in order to detect factors that could facilitate and/or hamper its utilisation in future scientific research.

Methods

Fifteen adults were recruited in the Orofacial Pain and Dysfunction Clinic of the Academic Centre for Dentistry Amsterdam (ACTA). Overnight recordings were performed in the home setting during one week. Time investment, feelings and thoughts, encountered difficulties and reasons for not using the device were assessed in a diary through open‐ended questions and 5‐point Likert scales. Content analysis of textual data was performed, and descriptives of quantitative data were calculated.

Results

Time investment was low (mean 10.2 minutes in the clinic, and 1.9 minutes per recording at home). Quantitative data showed an overall good experience (median of 4). Qualitative diary data showed that the desire to gain insight into one's masticatory muscle activity formed the main motivation to use the device. Device detachment and difficulty in using the app were the most prominent negative experiences.

Conclusion

The EMG device was well accepted for multiple overnight recordings. Curiosity for gaining insight into muscle activity was the most important factor that facilitated its use, and the app addressed this need. Device detachment and difficulties in using the app were the main factors that hampered its use.

An overview of pain in Parkinson's disease

Pain is a common non-motor symptom of Parkinson's disease (PD) and the prevalence of pain among PD patients varies because of the disease stage, co-morbidities, and evaluating tools. Risk factors for pain in PD include an early age of onset, long disease duration, motor complications, concomitant depressive symptoms, female gender, and associated medical conditions. In patients with PD, pain can be classified as musculoskeletal pain, chronic body pain (central or visceral), fluctuation-related pain, nocturnal pain, orofacial pain, pain with discolouration/oedema/swelling, and radicular/neuropathic pain; musculoskeletal pain as the most common type. Potential underlying mechanisms include a disruption of peripheral nociception and alterations in central pain threshold/processing. Genetic polymorphisms in genes that confer pain susceptibility might also play a role in the occurrence of pain in PD. In advanced stage of patients with PD, polyneuropathy could occur in patients using high dosage of levodopa. Pain often correlates to other non-motor symptoms of PD, including depression, sleep, and autonomic symptoms. Dopaminergic drugs, non-dopaminergic medications, botulinum toxin, deep brain stimulation, and physiotherapy have shown some benefits for certain types of PD-related pain. An increased awareness of pain as a common non-motor symptom of PD provides further insights into sensory system dysregulation in this disease. In this review, we aim to summarizes the clinical features of pain in patients with PD and emphasize the latest evidence of pain related to levodopa treatment.

The association between Parkinson's disease and temporomandibular disorder

The prevalence of temporomandibular disorder (TMD) among elderly people with Parkinson’s disease (PD) is relatively high, but a population-based study of the relationship between PD and TMD is still lacking. This study, therefore, sought to investigate the association between TMD and PD by using data for one million randomly sampled beneficiaries of Taiwan’s National Health Insurance program, including 6,185 PD patients who were matched through propensity score matching with 18,555 non-PD patients. Both the PD and non-PD cohorts were followed until death, any diagnosis of TMD, or December 31, 2013, whichever occurred first. Each diagnosis of TMD was made by a qualified physician according to the International Classification of Diseases, 9th Revision, Clinical Modification (ICD-9-CM), using the diagnosis codes 524.60, 524.62, 524.63, and 524.69 while excluding tooth abscess, wisdom tooth eruption, herpes zoster and postherpetic neuralgia, mastoiditis, otitis externa, otitis media, parotitis, sialadenitis, and trigeminal neuralgia. We used Cox proportional hazard regression models to calculate the relative risk of TMD and found a 2.11-fold (95% CI: 1.35–3.30) increased risk of TMD overall in the PD group compared with the non-PD group. Stratified by follow-up period, there was a 4.25-fold (95% CI: 1.51–11.93) increased risk in the PD group in the first year after the initial PD diagnosis and a 3.88-fold (95% CI: 1.33–11.28) increased risk in the second year. Over the long-term (>5 years), PD was significantly associated with an increased risk of TMD. These findings suggest that it is important to closely monitor the temporomandibular joint health of PD patients.

Prevalence of temporomandibular joint disorder in people with Parkinson’s disease in a public university hospital

ABSTRACT Objective: to evaluate the prevalence of temporomandibular joint disorder in people with Parkinson’s disease in a public university hospital, and relate it to sociodemographic factors, general health and oral health self-report, and phase and time of illness. Methods: the Research Diagnostic Criteria for Temporomandibular Disorders were used. The sample was classified according to the diagnosis of temporomandibular disorder and associated with the variables. The odds ratio of Chi-square was applied with a 95% confidence interval and a level of significance set at p<0.05. Results: 110 people presented with Parkinson's disease were assessed. The prevalence of temporomandibular disorder was 35%, being more frequent among males (58%), in elderly people (53%), in phase 2 of the disease (61%), click (37%) being the predominant clinical indication. Of the variables analyzed, only gender and self-perception of oral health showed to be associated with temporomandibular disorders. Conclusion: the presence of temporomandibular disorder has been observed in people with Parkinson's disease, and the fact of being male and reporting moderate oral health seen as associated factors.