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Objectives To investigate whether chronic temporomandibular disorder (TMD) patients showed any changes in swallowing compared to a control group. Moreover, it was examined whether swallowing variables and a valid clinic measure of orofacial myofunctional status were associated. Material and methods Twenty-three patients with chronic TMD, diagnosed with disc displacement with reduction (DDR) and pain, according to the Diagnostic Criteria for Temporomandibular Disorders (DC/TMD), and 27 healthy volunteers (control group) were compared. Surface electromyography (EMG) of the temporalis, masseter, sternocleidomastoid, and suprahyoid muscles was performed during swallowing tasks of thin liquid (10 and 15 mL) and spontaneous saliva. Data were normalized. Results Compared to the control group, TMD patients showed a prolonged duration of swallowing for liquid and saliva and required a longer time to reach the activity peak and half the integral. While the overall mean value of the relative peaks was similar for the groups, the suprahyoid peak was significantly lower in the TMD group during swallowing of liquid. Moreover, TMD patients recruited the jaw elevator muscles proportionally more than controls. The orofacial myofunctional status was moderately correlated with EMG parameters. Conclusion Patients with chronic TMD showed temporal prolongation and changes in the relative activity of the muscles during the swallowing tasks. Clinical relevance The present results contribute additional evidence regarding the reorganization of muscle activity in patients with chronic TMD.
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ORIGINAL ARTICLE
Swallowing changes related to chronic temporomandibular disorders
Carlos Eduardo Fassicollo
1
&Bárbara Cristina Zanandréa Machado
2
&Denny Marcos Garcia
2
&
Cláudia Maria de Felício
1,2
Received: 31 May 2018 /Accepted: 22 November 2018 /Published online: 28 November 2018
#Springer-Verlag GmbH Germany, part of Springer Nature 2018
Abstract
Objectives To investigate whether chronic temporomandibular disorder (TMD) patients showed any changes in swallowing
compared to a control group. Moreover, it was examined whether swallowing variables and a valid clinic measure of orofacial
myofunctional status were associated.
Material and methods Twenty-three patients with chronic TMD, diagnosed with disc displacement with reduction (DDR) and
pain, according to the Diagnostic Criteria for Temporomandibular Disorders (DC/TMD), and 27 healthy volunteers (control
group) were compared. Surface electromyography (EMG) of the temporalis, masseter, sternocleidomastoid, and suprahyoid
muscles was performed during swallowing tasks of thin liquid (10 and 15 mL) and spontaneous saliva. Data were normalized.
Results Compared to the control group, TMD patients showed a prolonged duration of swallowing for liquid and saliva and
required a longer time to reach the activity peak and half the integral. While the overall mean value of the relative peaks was
similar for the groups, the suprahyoid peak was significantly lower in the TMD group during swallowing of liquid. Moreover,
TMD patients recruited the jaw elevator muscles proportionally more than controls. The orofacial myofunctional status was
moderately correlated with EMG parameters.
Conclusion Patients with chronic TMD showed temporal prolongation and changes in the relative activity of the muscles during
the swallowing tasks.
Clinical relevance The present results contribute additional evidence regarding the reorganization of muscle activity in patients
with chronic TMD.
Keywords Temporomandibular disorders .Deglutition .Swallowing .Electromyography .Jaw muscles .Suprahyoid muscles
Introduction
The term temporomandibular disorder (TMD) defines a group
of musculoskeletal conditions that involve the temporoman-
dibular joints (TMJ), the masticatory muscles, and related
structures. Orofacial pains and a sensation of limitation of
mandibular functions are the dominant characteristics of
TMD [1,2]. Changes in behavior and in the masticatory phys-
iology have been reported in various studies [26]. Patients
with TMD also report swallowing difficulties [2,7], but little
is known about the electrophysiology of swallowing in this
population.
Swallowing is an essential orofacial function for the nutri-
tion and hydration of the organism. Its role is to guide excess
saliva or the food bolus from the oral cavity to the stomach,
while simultaneously protecting the airways. The motor con-
trol of the various muscles of the orofacial region and cervical
and respiratory muscles for efficient and safe swallowing is
started and guided by the central nervous system based on the
sensory information of the orofacial region. The oral phase of
swallowing can be controlled voluntarily, whereas the pharyn-
geal and esophageal phases are involuntary [810].
When swallowing, persons with proper occlusion and with
no disorders of the masticatory systemocclude their teeth [11].
The tongue then raises its tip in the direction of the alveolar
ridge and gradually expands the area of contact with the palate
from the anterior to the posterior region, compressing the bo-
lus into the pharynx [12]. In contrast, according to studies
*Cláudia Maria de Felício
cfelicio@fmrp.usp.br
1
Department of Ophthalmology, Otorhinolaryngology and Head and
Neck Surgery School of Medicine of Ribeirão Preto, University of
São Paulo USP, Avenida Bandeirantes, 3900, Ribeirão
Preto, SP 14049-900, Brazil
2
Craniofacial Research Support Center, University of São Paulo
USP, Ribeirão Preto, SP, Brazil
Clinical Oral Investigations (2019) 23:32873296
https://doi.org/10.1007/s00784-018-2760-z
Content courtesy of Springer Nature, terms of use apply. Rights reserved.
... Literatürde TMD'li olgularda eşlik eden OD problemlerini araştıran çalışma sayısı yetersiz olmakla birlikte (11,13,14) TMD ...
... 2019 yılında kronik TMD'si olan bireylerde yutma değişikliklerinin incelendiği bir çalışmanın sonuçları, orofasiyal miyofonksiyonel bozukluğun yutma süresinin uzaması ve sıvı yutma sırasında suprahyoid kaslarının aktivasyonunun azalması ile ilişkili olduğunu ortaya koymuştur. Ayrıca bu çalışma orofasiyal miyofonksiyonel bozukluğun tüm stomatognatik görevlerde artmış sternokleidomastoid kas aktivasyonunda artışa yol açtığını ve spontan tükürük yutma sırasında temporalis ve masseter kaslarının aktivasyonunu arttırdığını göstermiştir(14). ...
Thesis
Full-text available
Bu çalışma temporomandibular eklem disfonksiyonuna (TMD) bağlı oral evre yutma bozukluğu (Oral disfaji = OD) olan bireylerde uygulanan manuel tedaviye ek olarak dil kuvvetlendirme egzersizlerinin etkisinin araştırılması amacıyla planlandı. Çalışmamıza Şanlıurfa Viranşehir Devlet Hastanesi diş polikliniğine başvuran ve TMD’ye bağlı OD tanısı alan, 18-65 yaş arası, dahil edilme kriterlerine uyan ve tedaviyi tamamlayan 44 birey dahil edildi. Bireyler kapalı zarf usulü basit randomizasyon yöntemi ile kontrol grubu (n=12), manuel tedavi (MT) grubu (n=15) ve orofasyal miyofonksiyonel tedavi (OMT) grubu (n=17) olmak üzere üç gruba ayrıldı. Kontrol grubuna fizyoterapist tarafından düzenlenen ev egzersizi ve hasta eğitimi verildi. Bireylerden 10 hafta boyunca haftada 3 gün yapmaları istendi. MT grubuna aynı ev egzersizi ve hasta eğitimi ile birlikte temporomandibular eklem ve servikal bölgeyi içeren kapsamlı bir tedavi programı uygulandı. OMT grubuna ise ev egzersizi, hasta eğitimi ve MT’ye ek olarak dil kuvvetlendirme protokollerini içeren tedavi programı uygulandı. MT ve OMT gruplarına 10 hafta, haftada 2 seans, 30-45 dk süreyle 20 seans tedavi uygulandı. Tedavi sonrası 3. ayda ulaşılabilen 28 bireyin değerlendirmeleri tekrar alındı. Hastaların problemlerini ve tedavi sonrası iyileşmeyi değerlendirmek için Temporomandibular Rahatsızlıklar Araştırma Teşhis Kriterleri (TMR/ATK) Klinik Muayene Formu, baş postürü değerlendirme, Çenenin Fonksiyon Kısıtlanma Skalası-20 (ÇFKS-20), 100 ml su yutma testi (SYT), Yeme Değerlendirme Aracı (EAT-10), dil kuvvet ve endurans ölçümü, Yutma Yaşam Kalitesi Anketi (YYKA) ve Boyun Özür İndeksi (BÖİ) kullanıldı. Her üç grubun kendi içinde tedavi öncesi, tedavi sonrası ve 3. ay verileri karşılaştırıldığında, üç grupta da ağrı şiddeti, baş postürü, mandibula hareket açıklığı, çene fonksiyonelliği ve boyun özür seviyelerinde iyileşme görüldü (p<0.05). Kontrol grubunda yutma fonksiyonuna yönelik değerlendirmelerde gelişme görülmedi (p>0.05). MT grubunda yutma fonksiyonuna yönelik olan yalnızca SYT ve EAT-10 verilerinde iyileşme gözlendi (p<0.05). OMT grubunda SYT, EAT-10, YYKA ile dil kuvvet ve endurans verilerinin tamamında gelişme olduğu belirlendi (p<0.05). Tedavi sonrası gruplar birbiri ile karşılaştırıldığında, ağrı ve disfaji semptomlarında azalma ile çene fonksiyonelliği ve yutma yaşam kalitesi parametrelerinde en fazla artışın OMT grubunda görüldüğü tespit edildi (p<0.05). Sonuç olarak bu çalışmada ev egzersizleri ve MT’ye ek olarak dil kuvvetlendirme egzersizleri içeren OMT’nin yutma güçlüğünü azaltmada ve yutmaya bağlı yaşam kalitesini geliştirmede yalnızca MT ve egzersizlere göre daha üstün olduğu görüldü. Dolayısıyla, TMD’ye bağlı OD’si olan bireylerde OMT yaklaşımının ilave edilmesi önerilebilir.
... A literatura tem demonstrado que indivíduos com DTM apresentam alteração durante a mastigação e a deglutição, o que piora o desempenho dessas funções (5,7,(25)(26)(27)(28)(29) . Em estudo que avaliou sinais, sintomas e fatores associados em indivíduos com DTM, todos os pacientes relataram a existência de problemas mastigatórios, dentre eles, mastigação unilateral, dificuldade com alimentos duros, cansaço, dor e travamento mandibular (30) . ...
... Sabe-se que a qualidade da alimentação tem grande impacto na vida do indivíduo. Sendo assim, dificuldades na realização das funções de mastigação e deglutição, principalmente quando estão envolvidos os aspectos de dor e desconforto, geram prejuízo significativo na qualidade de vida desses pacientes (28) . ...
Article
Full-text available
Purpose To identify and synthesize evidence on strategies used to train chewing and swallowing in individuals with temporomandibular disorder and orofacial pain. Research strategy Scoping review conducted by search in MEDLINE, LILACS, BBO, IBECS, BINACIS, CUMED, SOF, DeCS, Index Psi, LIPECS, and ColecionaSUS (via VHL), Scopus, CINAHL, Embase, Web of Science, Cochrane, and the grey literature: Brazilian Digital Theses and Dissertations Library (BDTD), OpenGrey, and Google Scholar. Selection criteria Quantitative or qualitative studies, with no restriction on time or language of publication, with the following descriptors or keywords: Temporomandibular Joint; Temporomandibular Joint Dysfunction Syndrome; Temporomandibular Joint Disorders; Facial Pain; chewing (Mastication); swallowing (Deglutition); Therapeutics; Myofunctional Therapy; Speech, Language and Hearing Sciences. In the first stage, two reviewers independently screened the studies by title and abstract reading. In the second stage, the reviewers independently read the preselected documents in full text. In case of divergences, a third researcher was consulted. Results The 11 documents included in the review were published between 2000 and 2018. The mostly used training strategies were simultaneous bilateral mastication/chewing, followed by alternating bilateral mastication. In swallowing, increased mastication time was proposed to break food into smaller bits and better lubricate the bolus; training with upper tongue support was also indicated. Conclusion Functional training proved to be effective in rehabilitation, although it was not standardized or performed alone. The studies had low levels of evidence. It is essential to conduct more encompassing and standardized studies, such as randomized clinical trials. Keywords: Mastication, Deglutition; Temporomandibular Joint Dysfunction Syndrome; Myofunctional Therapy; Speech, Language and Hearing Sciences
... The literature has demonstrated that individuals with TMD have mastication and swallowing changes, which worsens the performance of these functions (5,7,(25)(26)(27)(28)(29) . In a study that assessed signs, symptoms, and associated factors in individuals with TMD, all patients reported masticatory problems, including unilateral mastication, difficulties with hard food, fatigue, pain, and jaw locking (30) . ...
... The quality of food is known to have a great impact on people's lives. Therefore, mastication and swallowing difficulties, especially when they involve pain and discomfort, significantly impair their quality of life (28) . ...
Article
Full-text available
Purpose To identify and synthesize evidence on strategies used to train chewing and swallowing in individuals with temporomandibular disorder and orofacial pain. Research strategy Scoping review conducted by search in MEDLINE, LILACS, BBO, IBECS, BINACIS, CUMED, SOF, DeCS, Index Psi, LIPECS, and ColecionaSUS (via VHL), Scopus, CINAHL, Embase, Web of Science, Cochrane, and the grey literature: Brazilian Digital Theses and Dissertations Library (BDTD), OpenGrey, and Google Scholar. Selection criteria Quantitative or qualitative studies, with no restriction on time or language of publication, with the following descriptors or keywords: Temporomandibular Joint; Temporomandibular Joint Dysfunction Syndrome; Temporomandibular Joint Disorders; Facial Pain; chewing (Mastication); swallowing (Deglutition); Therapeutics; Myofunctional Therapy; Speech, Language and Hearing Sciences. In the first stage, two reviewers independently screened the studies by title and abstract reading. In the second stage, the reviewers independently read the preselected documents in full text. In case of divergences, a third researcher was consulted. Results The 11 documents included in the review were published between 2000 and 2018. The mostly used training strategies were simultaneous bilateral mastication/chewing, followed by alternating bilateral mastication. In swallowing, increased mastication time was proposed to break food into smaller bits and better lubricate the bolus; training with upper tongue support was also indicated. Conclusion Functional training proved to be effective in rehabilitation, although it was not standardized or performed alone. The studies had low levels of evidence. It is essential to conduct more encompassing and standardized studies, such as randomized clinical trials. Keywords: Mastication, Deglutition; Temporomandibular Joint Dysfunction Syndrome; Myofunctional Therapy; Speech, Language and Hearing Sciences
... Exercise and manual treatment methods combined with other therapeutic agents are widely used in TMD rehabilitation [16,17]. However, few studies have investigated accompanying problems [14,18,19] and treatment approaches [20] in TMD cases with coexistent oral stage swallowing problems. It has been emphasized that there is a need for effective approaches to swallowing problems in treating TMD [20,21]. ...
Article
Full-text available
Objective: Patients with temporomandibular dysfunction (TMD) may develop oral-stage dyspha-gia (OD) in the chronic phase. Methods: This study investigated the effect of orofacial myofunctional therapy (OMT) in individuals with TMD-related OD. Fifty-one patients aged 18-65 years with TMD-related OD were separated into three groups using a simple randomization method: the control group (n = 12) underwent patient education and a home-exercise program; additionally, to an exercise program the manual therapy (MT) group (n = 19) received MT; and the OMT group (n = 20) received the OMT program. MT and OMT were applied in two sessions per week for 10 weeks. The patients were re-evaluated after treatment and at 3 months. Results: The OMT group showed the most improvement in jaw functionality, swallowing-related quality of life, pain, and dysphagia (p < .05). Discussion: OMT was superior to MT and exercises alone in reducing dysphagia and improving the swallowing-related quality of life.
... Exercise and manual treatment methods combined with other therapeutic agents are widely used in TMD rehabilitation [16,17]. However, few studies have investigated accompanying problems [14,18,19] and treatment approaches [20] in TMD cases with coexistent oral stage swallowing problems. It has been emphasized that there is a need for effective approaches to swallowing problems in treating TMD [20,21]. ...
Article
Full-text available
Objective: Patients with temporomandibular dysfunction (TMD) may develop oral-stage dysphagia (OD) in the chronic phase. Methods: This study investigated the effect of orofacial myofunctional therapy (OMT) in individuals with TMD-related OD. Fifty-one patients aged 18-65 years with TMD-related OD were separated into three groups using a simple randomization method: the control group (n = 12) underwent patient education and a home-exercise program; additionally, to an exercise program the manual therapy (MT) group (n = 19) received MT; and the OMT group (n = 20) received the OMT program. MT and OMT were applied in two sessions per week for 10 weeks. The patients were re-evaluated after treatment and at 3 months. Results: The OMT group showed the most improvement in jaw functionality, swallowing-related quality of life, pain, and dysphagia (p < .05). Discussion: OMT was superior to MT and exercises alone in reducing dysphagia and improving the swallowing-related quality of life.
... Therefore, women with chronic TMDs may show lower PF values in association with swallowing disorders. Fassicollo et al. agreed with this hypothesis and found that patients with chronic TMDs need more time to perform fluid and saliva swallowing, which could be due to weak tongue function [44]. We hypothesize that the swallowing dysfunction observed in patients with chronic TMDs may be due to a significant decrease in the PF. ...
Article
Full-text available
Background: Temporomandibular disorders are craniofacial disorders characterized by the presence of chronic pain in masticatory muscles, with higher incidence in the women population. There is little research that has studied tongue force related to temporomandibular disorders, but there are a lot of studies that have demonstrated the impact of tongue force in vital functions, such as chewing, swallowing, phonation, or breathing. According to this, the aim of this study was to compare the maximum force of the tongue between females with chronic temporomandibular disorders and asymptomatic females. We also wanted to establish whether any relationship existed between the pain and fatigue versus the maximum force developed in females with chronic temporomandibular disorders. Material and methods: A cross-sectional study of 67 women between the ages of 18 and 65 years old was performed. The included women were assigned to one of two groups, according to whether they had chronic temporomandibular disorders or not. The procedure was the same for both groups. Outcome measures included the maximum tongue force, intensity of perceived orofacial pain, and intensity of perceived orofacial fatigue. Results: The results showed significant statistical differences for the maximum tongue force measurement between the chronic temporomandibular disorders group and the control group (p < 0.05) for all the movements, except the lip pressure measurement. Furthermore, the analysis revealed significant statistical differences between the intensity of perceived orofacial fatigue between the groups (p < 0.05). Moreover, the data showed no significant correlations between variables. Conclusion: The study found significant differences in maximum tongue force when comparing women with chronic temporomandibular disorders and asymptomatic women (being superior in these). Likewise, we found that the intensity of perceived orofacial fatigue after tongue exercises showed significant differences between groups. However, this study reveals no correlations between the intensity of perceived orofacial pain and fatigue and the maximum tongue force.
... Common causes include emotional stress, trauma, joint overload, and genetics. Due to frequent joint movement, the disease has a long treatment course, ranging from a few weeks to several years, and is also prone to recurrence [6]. Its pathogenesis is complex, and surgical treatment is required for patients who fail to receive conservative treatment [7]. ...
Article
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Objective: This study aimed to explore the effects of individualized nursing in patients with temporomandibular disorders (TMD). Methods: From June 2019 to April 2021, 80 patients with TMD were admitted to the First Affiliated Hospital of Wenzhou Medical University. Among them, 40 patients (control group, CG) received routine nursing and 40 patients (experimental group, EG) received individualized nursing. Functional exercise compliance, pain score, maximum mouth opening, nursing satisfaction questionnaire, self-rating anxiety scale, and self-rating depression scale were investigated. Results: From June 2019 to April 2021, 81 patients with TMD were admitted to the First Affiliated Hospital of Wenzhou Medical University. Among them, 40 patients (control group) received routine care and 41 patients (experimental group) received individual care. There were no significant differences in mouth opening and pain score between the two groups before surgery (P > 0.05), but there were significant differences in mouth opening and pain score between the two groups 3 weeks after surgery. Patients' anxiety and depression were assessed by the SAS and SDS scores. Before nursing, the control group and experimental group (P < 0.05) had no significant difference. After nursing, the score of both groups decreased (P < 0.05). However, the score was lower in the experimental group, compared to the control group (P < 0.01). Conclusion: In summary, individualized nursing can improve patients' physical condition and reduce negative emotions and complications. In light of this, the study needs further verification by a large sample randomized controlled trial.
Chapter
This chapter delves into the crucial stomatognathic function of deglutition. By employing electromyography and mandibular scanning techniques, we can effectively identify various tongue dysfunctions that are of particular interest in the field of orthodontics. The author puts forth a hypothesis on primary and secondary tongue thrust, shedding light on this important aspect of the subject. It is imperative to note that an ideal dental occlusion cannot be achieved without an optimal swallow pattern. As such, identifying the correlation between tongue function and malocclusion is a crucial step in the diagnosis of neuromuscular orthodontic conditions. By exploring this link, we can gain a deeper understanding of the underlying factors contributing to the development of malocclusion and develop more effective treatment strategies. Continued exploration and investigation into the subject of deglutition and its relationship with orthodontic conditions is essential for advancing the field and improving patient outcomes.
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Dysphagia is sometimes accompanied by pain. Because orofacial structures subserve mastication and swallowing, orofacial pain might impair both functions. Tongue biting can occur not only accidentally while eating but also in some pathological conditions. However, it remains unclear whether noxious mechanical stimulation of the tongue affects swallowing. To explore this question, we evaluated the effects of lingual pinch stimulation on the initiation of swallowing evoked by distilled water (DW) infusion with a flow rate of 5.0 µL/s for 20 s into the pharyngolaryngeal region in anesthetized rats. The swallowing reflex was identified by electromyographic (EMG) bursts in the suprahyoid muscles which include the anterior belly of the digastric muscle, mylohyoid and geniohyoid muscles, and laryngeal elevation by visual inspection. The number of DW-evoked swallows during pinch stimulation was significantly smaller than that in a control condition or during pressure stimulation. The onset latency of the first swallow during pinch stimulation was significantly longer than that in the control condition. DW-evoked swallowing was almost abolished following bilateral transection of the superior laryngeal nerve (SLN) compared with the control condition, suggesting that the SLN plays a crucial role in the initiation of DW-evoked swallowing. Finally, electrophysiological data indicated that some SLN-responsive neurons in the nucleus tractus solitarii (nTS) exhibited delayed latency from a single SLN stimulation during lingual pinch stimulation. These results suggest that noxious mechanical stimulation of the tongue inhibits the initiation of swallowing and modulates neuronal activity in the nTS.
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Introduction: Temporomandibular disease (TMD) etiology is multifactorial and is related to many perpetuating, predisposing, and initiating factors. The daytime parafunctions may have an important role in TMD pathogenesis. The most frequent parafunctions analyzed were the static parafunction (ie, clenching) and the dynamic parafunction (ie, grinding). In the present paper, the authors evaluated the swallowing (an oral function/parafunction) with the surface electromyography in patients with TMD. Materials and methods: Twenty patients with TMD problems (nonhealthy patients, NHP) (mean age: 33 ± 1.994; 8 men and 12 women) and 20 healthy matched subjects (HP) (34.4 ± 2.782; 6 men and 14 women) were selected and examined. On each patient, an 8-channel surface electromyography was done during saliva swallowing. Results: Nonhealthy patients presented higher masseter and temporalis activation (P < 0.05) and an unbalancing of temporalis and submental muscles activation (P < 0.05) than the HP. Discussion: Nonhealthy patients presented a time of swallow higher than HP (P < 0.001). Nonhealthy patients presented a higher muscles activation and time of swallow than HP and a decrease of muscles balancing activation.
Article
Objective Repetitive jaw‐muscle activity characterized by clenching or grinding of the teeth and/or by bracing or thrusting of the mandible, ie, bruxism, is traditionally linked to pain and unpleasantness in the active muscles. The aim of this study was to investigate the effects of standardized craniofacial muscle contractions on self‐reported symptoms. Methods Sixteen healthy volunteers performed six 5‐minute bouts of 20% maximal voluntary contraction task of the jaw‐closing (Jaw), the orbicularis‐oris (O‐oris), and the orbicularis‐oculi (O‐oculi) muscles. Participants rated their perceived pain, unpleasantness, fatigue, and mental stress levels before, during, and after the contraction tasks on 0‐10 Numeric Rating Scales (NRS). Each muscle contraction task (= 1 session) was separated by at least 1 week and the order of the sessions was randomized in each subject. Results All muscle contraction tasks evoked significant increases in NRS scores of pain (mean ± SD: Jaw; 3.8 ± 2.7, O‐oris; 1.9 ± 2.2, O‐oculi; 1.4 ± 1.3, P < .014), unpleasantness (Jaw; 4.1 ± 2.5, O‐oris; 2.1 ± 1.9, O‐oculi; 2.9 ± 1.8, P < .001), fatigue (Jaw; 5.8 ± 2.0, O‐oris; 3.2 ± 2.3, O‐oculi; 3.6 ± 1.9, P < .001), and mental stress (Jaw; 4.1 ± 2.1, O‐oris; 2.2 ± 2.7, O‐oculi; 2.9 ± 2.2, P < .001). The Jaw contractions were associated with higher NRS scores compared with the O‐oris and the O‐oculi contractions (P < .005) without differences between the O‐oris and the O‐oculi (P > .063). All symptoms disappeared within 1 day (P > .469). Conclusions The results showed that submaximal static contractions of different craniofacial muscle groups could evoke transient, mild to moderate levels of muscle pain and fatigue and increased stress scores. The fatigue resistance may differ between different muscle groups. Further studies are warranted to better understand the contribution of specific craniofacial muscle groups for the characteristic presentation of musculoskeletal pain conditions in the head.
Article
Objective: Temporomandibular disorders (TMDs) are the most commonly experienced non-dental orofacial pain disorders, with pain and dysfunction potentially resulting in oral stage dysphagia (OD). However, limited research has been conducted on this condition, with potential negative effects on clinical practice. Therefore, the aim of this study was to determine the prevalence of OD in adults presenting with TMDs, diagnosed as per the Research Diagnostic Criteria for Temporomandibular Disorders or the Diagnostic Criteria for Temporomandibular Disorders protocols. Material and methods: A systematic review of the literature was completed. Nine electronic databases were searched from inception to January 2017, with no date/language restriction applied. Grey literature, conference proceedings, and reference lists were also searched. Studies presenting original data regarding OD prevalence in adults presenting with TMDs were included if they investigated impaired swallowing, mastication, masticatory pain or fatigue, or weight loss. Study eligibility and quality were assessed by two independent reviewers. Methodological quality was assessed using the Down’s and Black tool. Results and conclusions: This search yielded 20 eligible studies. Swallowing itself was impaired in only 9.3% of patients with TMDs. A range of additional OD signs and symptoms were also commonly reported (e.g. masticatory pain (87.4%) and fatigue (62%)). Study limitations included the small number of studies which were eligible for inclusion. As signs and symptoms of OD are frequently reported by patients with TMDs, psychometrically robust prospective research is warranted to determine current and optimal management of this condition.
Article
The orofacial sensorimotor system is a unique system significantly distinguished from the spinal sensorimotor system. The jaw muscles are involved in mastication, swallowing and articulatory speech movements and their integration with respiration. These sensorimotor functions are vital for sustaining life and necessitate complex neuromuscular processing to provide for exquisite sensorimotor control of numerous orofacial muscles. The function of the jaw muscles in relation to sensorimotor control of these movements may be subject to aging-related declines. This review will focus on peripheral, brainstem and higher brain centre mechanisms involved in reflex regulation and sensorimotor coordination and control of jaw muscles in healthy adults. It will outline the limited literature bearing on age-related declines in jaw sensorimotor functions and control including reduced biting forces and increased risk of impaired chewing, speaking and swallowing. The mechanisms underlying these alterations include age-related degenerative changes within the peripheral neuromuscular system and in brain regions involved in the generation and control of jaw movements. In light of the vital role of jaw sensorimotor functions in sustaining life, normal aging involves compensatory mechanisms that utilize the neuroplastic capacity of the brain and the recruitment of additional brain regions involved in sensorimotor performance and closely associated functions (e.g., cognition and memory). However, these regions are themselves susceptible to detrimental age-related changes. Thus, better understanding of the peripheral and central mechanisms underlying age-related sensorimotor impairment is crucial for developing improved treatment approaches to prevent or cure impaired jaw sensorimotor functions and to thereby improve health and quality of life.
Article
The aims of this pilot study were to evaluate: i) the reproducibility and variability of an electromyographical protocol developed for the assessment of submental muscles (SM) ii) to apply the new protocol to maximal teeth clenching, a simple and largely studied static task in order to quantify the relative contribution of submental muscles. In 20 healthy subjects, aged 19-35 years, surface electromyography of SM, masseter (MM) and anterior temporalis (TA) muscles was performed during maximal voluntary clenching (MVC) with and without cotton rolls and the pushing of the tongue against the palate. Clenching on cotton rolls and pushing the tongue against the palate were used to standardise respectively MM and TA, and SM muscular potentials. The exercises were repeated in two appointments (T1-T2); submental muscles standardisation was also repeated twice (A-B) in each session to assess repeatability. Symmetry and activity were calculated for each couple of muscles. A two-way analysis of variance was computed for SM: no Factor 1 (T1 vs T2) or Factor 2 (A vs B) or F1 X F2 significant effects were found. SM recruitment was 31% of the maximal activity, with symmetry values larger than 80%. In conclusion, standardised electromyography allows a reliable assessment of Submental muscles activity.
Article
Objective: To investigate whether reorganization of muscle activity occurs in patients with chronic temporomandibular disorders (TMD) and, if so, how it is affected by symptomatology severity. Methods: Surface electromyography (sEMG) of masticatory muscles was made in 30 chronic TMD patients, diagnosed with disc displacement with reduction (DDR) and pain. Two 15-patient subgroups, with moderate (TMDmo) and severe (TMDse) signs and symptoms, were compared with a control group of 15 healthy subjects matched by age. The experimental tasks were: a 5s inter-arch maximum voluntary clench (MVC); right and left 15s unilateral gum chewing tests. Standardized sEMG indices characterizing masseter and temporalis muscles activity were calculated, and a comprehensive functional index (FI) was introduced to quantitatively summarize subjects' overall performance. Mastication was also clinically evaluated. Results: During MVC, TMDse patients had a significantly larger asymmetry of temporalis muscles contraction. Both TMD groups showed reduced coordination between masseter and temporalis muscles' maximal contraction, and their muscular activity distribution shifted significantly from masseter to temporalis muscles. During chewing, TMDse patients recruited the balancing side muscles proportionally more than controls, specifically the masseter muscle. When comparing right and left side chewing, the muscles' recruitment pattern resulted less symmetric in TMD patients, especially in TMDse. Overall, the functional index of both TMDmo and TMDse patients was significantly lower than that obtained by controls. Conclusions: Chronic TMD patients, specifically those with severe symptomatology, showed a reorganized activity, mainly resulting in worse functional performances.