Effect of tongue position on masseter and temporalis electromyographic activity during swallowing and maximal voluntary clenching: a cross‐sectional study

The purpose of this study was to measure and compare the tonic electromyographic (EMG) activity of the temporalis and masseter muscles following placement of the tongue either on the palate or in the floor of the mouth during swallowing and maximal voluntary clenching (MVC). Thirty healthy dental students with natural dentition and bilateral molar support, between the ages of 18 and 22, with no prior history of oro‐facial injury, or current or past pain in the jaw, mouth or tongue participated in the study. Tonic masseter and temporalis EMG activities were recorded using surface electrodes. Subjects were instructed to passively place the tongue either on the anterior hard palate or in the floor of the mouth during swallowing and MVC. At each tongue position, the resulting EMG was recorded. During swallowing, no significant difference in EMG activity was found either for the masseter (P‐value = 0·1592) or the temporalis (P‐value = 0·0546) muscles, regardless of the tongue position. During MVC, there was a statistically significant difference for both the masseter (P‐value = 0·0016) and the temporalis (P‐value = 0·0277) muscles with lower levels recorded with the tongue in the floor of the mouth. This study found that in normal, pain‐free subjects, placing the tongue in the floor of the mouth significantly reduces masticatory muscle activity during MVC. Thus, it may be considered as a possible therapeutic option to decrease masticatory muscle activity; however, further research is needed in patients with oro‐facial pain.     

Nonodontogenic Odontalgia Referred from the Temporal Tendon: A Case Report

IntroductionTemporal tendonitis (TT) is an orofacial pain disorder that can refer pain to the maxillary and mandibular molars, temporomandibular joint, masticatory muscles, eye, or ear. Patients often present to a dentist or physician with complaints reflecting these referral patterns, yet many healthcare providers are unfamiliar with TT because of the scarcity of literature published on this clinical entity. This may lead to diagnostic confusion, iatrogenic harm, and prolonged patient suffering.Methods and ResultsThis case report describes TT that presented as maxillary and mandibular posterior tooth pain, preauricular pain, and decreased mandibular range of motion. Patient history and examination were suggestive of TT. Local anesthetic injection adjacent to the tendon eliminated all pain complaints and improved range of motion. The patient was given education on the condition and self-care instructions. At 1-week follow-up, the patient reported resolution of her pain complaint.ConclusionsAs healthcare providers familiarize themselves with appropriate diagnostic and treatment options for TT, delayed or unnecessary care can be avoided, and proper management strategies can be implemented.     

Efficacy of biofeedback therapy on sleep bruxism: A systematic review and meta‐analysis

This study updates the review published by Wang et al in 2014 (Sleep Breath 2014;18(2):235‐242). The review focuses on the most recent literature on management of sleep bruxism (SB) with biofeedback. An electronic search was conducted in five databases searching for articles published later than the date of Wang et al's search, viz., October 2012. Six articles of 2320 identified citations involving 86 adult participants were included in the qualitative synthesis. Of them, 4 were randomised controlled trials (RCTs) and 2 were uncontrolled before‐after studies. Different feedback modalities (electrical, auditory and vibratory stimulus) were investigated. The overall quality of the selected studies was assessed using the GRADE criteria. Due to heterogeneity between studies, the quantitative synthesis was performed out of three RCTs, of which two were retrieved from the previous review. The meta‐analysis indicated a non‐significant difference in electromyographic‐measured SB episodes per hour after one night of contingent electrical stimulation (CES) compared with placebo control, yet a significant difference was shown after five nights of CES. The quality of evidence identified through GRADEpro was from low to moderate, due to imprecision and inconsistency between studies. Qualitative synthesis did not present a reliable reduction in clinical pain levels; however, no substantial sleep disturbances were indicated following the intervention. In conclusion, one of the biofeedback modalities, CES, is effective in reducing SB‐related motor activities after a short‐term treatment period. However, evidence of long‐term effects is lacking. Further longitudinal studies with larger samples are necessary to acknowledge the clinical application of biofeedback.     

A novel vibratory stimulation‐based occlusal splint for alleviation of TMD painful symptoms: a pilot study

This pilot study introduces a novel vibratory stimulation‐based occlusal splint (VibOS) for management of pain related to temporomandibular disorders (TMD). The study sample consisted of 10 patients (mean age: 40·5 ± 13·7 years, male/female: 3/7) who were using stabilisation splints for more than 2 months prior to the study onset and still complained of pain. Patients utilised the active and inactive VibOS during 15 days in a crossover designed clinical trial. The analysed variables were self‐reported VAS pain levels and number of painful sites to palpation (PSP). Statistical analysis was performed with repeated measures anova . At baseline, mean VAS pain levels for group I and II were 45·6 ± 21·0 mm and 37·4 ± 16·3 mm, respectively. Comparison between these baseline values showed no statistical difference (P > 0·05, unpaired t‐test). In group I, the inactive VibOS caused a slight increase in VAS pain levels, whereas the active VibOS promoted a significant decrease in VAS pain levels and PSP (P < 0·01). In group II, which received the active VibOS first, a significant decrease in VAS levels (P < 0·05) and in PSP (P < 0·01) was observed. No significant decrease in VAS pain levels or PSP (P > 0·05) was observed with the use of the inactive VibOS. In conclusion, this study demonstrated a good tendency of this novel VibOS in the alleviation of painful symptoms related to TMD after a 15‐day management period compared to control VibOS.     

Development of a speech‐discriminating electromyogram system for routine ambulatory recordings for the low‐level masseter muscle activity

Previous work suggests a relationship between sustained low‐level tooth clenching and the aetiology of myogenous temporomandibular disorder (TMD) pain. This study aimed to establish a reliable system with which to evaluate low‐level electromyographic (EMG) activity related to low‐level tooth clenching while discriminating speech activity, which is one of the most common facial muscle activities to be discriminated from low‐level clenching. This device should facilitate the clinical evaluation of awake muscle activity in TMD patients. Eight female and eight male subjects (38·9 ± 11·3 years) participated in the study to evaluate the validity of estimation of speech duration. Actual speech duration was defined by one examiner by pointing out the timing of beginning and end point of each speech on wave‐editing software. Speech duration, as detected by a voice sensor system, which was activated by a voice loudness of 54·71 ± 5·00 dB, was significantly correlated with the above actual speech duration (P < 0·01, R² = 0·9935). An actual recording with the system was carried out in one TMD patient and one healthy volunteer and revealed that the duration of diurnal EMG activity higher than 5% MVC was 1649·16 s and 95·99 s, respectively. As the voice sensor system adopted in this study could define the exact onset and offset of each segment of speech, EMG activity during speech could be precisely discriminated. The results of this study demonstrate that the EMG system with voice sensor system would be an effective tool for the evaluation of low‐level masticatory muscle activity.     

An oral rehabilitation robot for massaging the masseter and temporal muscles: a preliminary report

Objectives  This study determined suitable conditions for masseter and temporal muscle massage using a specially fabricated robot and evaluated its effects on patients with TMJ dysfunction associated with myofascial pain. Methods  The robot was designed with two arms with six degrees-of-freedom, and equipped with plungers. A phase-1 trial examined 22 healthy volunteers to determine its safety and suitable massage pressure, examining three different pressures. The volunteers evaluated their comfort, warmth, and ease of mouth opening by use of a visual analogue scale (VAS). A phase-2 trial examined the safety, suitable dose regimen, and efficacy in 12 patients. Maximal mouth opening was measured, and muscle pain and massage were evaluated subjectively. Results  The robot was safe in the phase-1 trial, except for two massages in which the pressure was excessive. Massages at 6–10 N were given the highest VAS scores. In phase 2, the massage pressure was arbitrary and each muscle was massaged seven times for 1 min, three times every two weeks. After evaluating the efficacy, additional treatments were performed at a greater pressure or for longer. The massage treatment was very effective for most patients. Conclusion  The massage treatment was safe and effective for most patients when administered at a pressure of 6–10 N seven times for 1 min per muscle every two weeks. The robot may constitute a useful tool for treating TMJ dysfunction associated with myofascial pain.     

Lateral cephalometric analysis of mandibular morphology: discrimination among subjects with and without temporomandibular joint disk displacement and osteoarthrosis

Summary To assess whether in patients with temporomandibular joint (TMJ) arthralgia cephalometric variables of mandibular morphology may discriminate among the magnetic resonance (MR) imaging‐based TMJ groups of ‘bilateral presence of disk displacement without reduction (DDwoR) and osteoarthrosis (OA)’ and ‘bilateral absence of bilateral DDwoR and OA’. Bilateral MR imaging of the TMJ was performed in 45 consecutive TMJ arthralgia patients to identify individuals with the specific structural characteristics of bilateral TMJ DDwoR associated with OA. Linear and angular cephalometric measurements were taken from lateral cephalograms to apply selected criteria of mandibular morphology. A discriminant function analysis was used to investigate how cephalometric parameters discriminate among the TMJ groups of ‘bilateral presence of DDwoR with OA’ and ‘bilateral absence of DDwoR and OA’. Ramus height (Ar‐Go) and effective mandibular length (Ar‐Pog) produced a significant discriminant function that predicted TMJ group membership (P < 0·001). This function correctly classified 80·2% of original and cross‐validated grouped cases. This study supports the concept that cephalometric variables of mandibular morphology discriminate among subjects with and without bilateral TMJ DDwoR and OA.     

Influence of nocturnal bruxism on the stomatognathic system. Part I: a new device for measuring mandibular movements during sleep

The purpose of this study was to investigate the influence of bruxism on the stomatognathic system. A new device for measuring nocturnal mandibular movements was developed using a PIN photodiode sensor, integrated with polysomnography including electromyography (EMG), electroencephalography (EEG) and electro oculography (EOG). One bruxing event was defined depending upon EMG activities above 5% maximum voluntary contraction (MVC), and mandibular movement for each event was classified into three patterns (clenching, grinding and mix). Three subjects were selected for this study. Two of these reported a bruxing habit and one subject had some symptoms of temporomandibular dysfunction (TMD). Mandibular movement was analysed for these subjects. Frequency and duration of the bruxism events were 4.5-10.9 and 47.8-174.9 s h(-1) respectively. Clenching type bruxism was most frequently observed for all three subjects and EMG activities during clenching were stronger than grinding.     

Efficacy of an early intervention for patients with acute temporomandibular disorder-related pain: a one-year outcome study

BACKGROUND: The authors conducted a randomized clinical trial to evaluate the efficacy of a biopsychosocial intervention for patients who were at high risk (HR) of progressing from acute to chronic temporomandibular disorder (TMD)-related pain. METHODS: The authors classified subjects' risk using a predictive algorithm and randomized them into an early-intervention (EI) or a nonintervention (NI) group. The EI included cognitive behavioral skills training and biofeedback. The authors assessed pain and psychosocial measures at intake and at a one-year follow-up. Subjects' self-reported pain levels were measured on an analog scale and as a response to palpation. RESULTS: At one year, EI-group subjects had significantly lower levels of self-reported pain and depression. At one year, more NI-group subjects than EI-group subjects had utilized health care for jaw-related pain. NI-group subjects were 12.5 times as likely to have a somatoform disorder, more than seven times as likely to have an anxiety disorder, and 2.7 times more likely to have an affective disorder at one year, compared with EI-group subjects. CONCLUSIONS: EI-group subjects had reduced pain levels, improved coping abilities and reduced emotional distress at one year. CLINICAL IMPLICATIONS: The TMD-related pain experience is complex and requires early identification with a biopsychosocial EI to achieve maximal, sustainable results.     

Referred Orofacial Pain as an Initial Symptom of Distant,Nonmetastatic Cancer: Report of a Case and Review of the Literature

Referred orofacial pain as the first symptom of an otherwise silent distant, nonmetastatic cancer has been reported, but there is sparse literature on the subject. Referred pain may not be considered in the orofacial pain differential diagnosis because of its rarity; however, this may delay a cancer diagnosis. The authors present a case report and a review of the English literature. Peer-reviewed publications were identified through a systematic search of MEDLINE, Embase, and Cochrane CENTRAL. Historic cases were reviewed, and available data regarding demographics, pain characteristics, treatment, cancer diagnosis, and outcome were extracted. Thirty-seven cases were identified. All cancers were intrathoracic. The average age was 54.1 years with a slight female predominance (3:2). Common pain characteristics were (1) diffuse location affecting the ear (76%), jaw (46%), and temple (30%); (2) constant duration (65%); (3) aching quality (74%); (4) severe intensity (94%); and (5) associated systemic symptoms (68%) such as weight loss and digital clubbing. The average time from the onset of facial pain to seeking medical attention was 9 months, and the average time from seeking medication attention to cancer diagnosis was 8 months. Orofacial pain was often attributed to odontogenic (35%) or neuropathic (25%) causes, and treatments for these conditions were also common. The impact of referred orofacial pain on the cancer prognosis was not possible because of the nature of the reviewed studies (case reports with no comparison group). Cancer-associated referred orofacial pain as a first symptom is rare but should be considered in cases with intractable pain and associated systemic symptoms.     

Interprofessional Collaboration in Dentistry: Role of physiotherapists to improve care and outcomes for chronic pain conditions and sleep disorders

Physiotherapists can manage chronic pain patients by using technical interventions such as mobility, strengthening, manual therapy, or flexibility in a specific and functional manner, being a key component of a multidisciplinary team. Dentists are involved in the management of different chronic pain conditions such as temporomandibular disorders and sleep disorders such as obstructive sleep apnea. However, they are frequently unaware of the benefits of collaborating with physical therapists. In this review, the collaboration of physical therapists and dentists will be explored when managing orofacial pain, headaches, and sleep disorders. The physical therapist is important in the management of these disorders and also in the screening of risk factors.     

Potential clinical application of masseter and temporal muscle massage treatment using an oral rehabilitation robot in temporomandibular disorder patients with myofascial pain

Objectives: To investigate the safety, suitable treatment regimen, and efficacy of masseter and temporal muscle massage treatment using an oral rehabilitation robot.

Methods: Forty-one temporomandibular disorder (TMD) patients with myofascial pain (8 men, 33 women, median age: 46 years) were enrolled. The safety, suitable massage regimen, and efficacy of this treatment were investigated. Changes in masseter muscle thickness were evaluated on sonograms.

Results: No adverse events occurred with any of the treatment sessions. Suitable massage was at pressure of 10 N for 16 minutes. Five sessions were performed every 2 weeks. Total duration of treatment was 9·5 weeks in median. Massage treatment was effective in 70·3% of patients. Masseter muscle thickness decreased with treatment in the therapy-effective group.

Conclusion: This study confirmed the safety of massage treatment, and established a suitable regimen. Massage was effective in 70·3% of patients and appeared to have a potential as one of the effective treatments for myofascial pain.     

Timing of arthrocentesis in the management of temporomandibular disorders: an integrative review and meta-analysis

The aim of this study was to assess the best timing to perform arthrocentesis in the management of temporomandibular disorders with regard to conservative treatment. A systematic search based on PRISMA guidelines, including a computer search with specific keywords, reference list search, and manual search was performed. Relevant articles were selected after three search rounds for final review based on six predefined inclusion criteria, followed by a round of critical appraisal. Eleven publications, including eight randomized controlled trials and three prospective clinical studies, were included in the review. The studies were divided into three groups based on the timing of arthrocentesis: (1) arthrocentesis as the initial treatment; (2) early arthrocentesis; and (3) late arthrocentesis. Meta-analysis was carried out to compare the efficacy of improvement in mouth opening and pain reduction in the three groups. All three groups showed improvement in mouth opening and pain reduction, with forest plots suggesting that arthrocentesis performed within 3 months of conservative treatment might produce beneficial results. We conclude that there is a knowledge gap in the current literature regarding the preferable timing to perform arthrocentesis in the management of temporomandibular disorders, and more high-quality randomized controlled trials are required to shed light on this subject.     

The role of soft tissue mobilization in reducing orofacial and general complaints in a patient with Kimmerle anomaly and temporomandibular joint disorder: A case report

ABSTRACT

Background: Kimmerle anomaly belongs to the anatomic varieties of the first cervical vertebra. The clinical pattern is dominated by vascular- and neurogenic-type headaches, dizziness, decreased postural muscle tension, and vegetative symptoms.

Clinical Presentation: A 37-year-old woman who suffered from headache and pain in the left temporomandibular joint underwent clinical examination, electromyography of masticatory muscles, temporomandibular joint vibration analysis, cone beam computed tomography, and soft tissue mobilization. Radiologic examination revealed Kimmerle anomaly on the right side of the atlas.

Clinical Relevance: Myofascial release decreased the tension within anatomic structures projected to the vertebral artery groove. Better movements of the cervical spine and fewer headaches were noted. Increased cervical and masseter muscle tension were considered the main cause of the ailments. The proprioceptive system of the cervical spine was accepted as a reason for persistent headaches. Soft tissue mobilization revealed positive healing effect in the patient with temporomandibular joint disorder and Kimmerle anomaly.

Abbreviations: C1: First cervical vertebra; DC/TMD: Diagnostic Criteria for Temporomandibular Disorders (DC/TMD); BDI: Beck Depression Inventory; PSS: Perceived Stress Scale; NDI: Neck Disability Index; BioEMG: Surface electromyography; sEMG: Surface electromyography; ICC: Intraclass correlation coefficient; T-Scan® III: computer evaluation of dental occlusion; JVA: Joint Vibration Analysis; CBCT: Cone Beam Computed Tomography; TO: Occlusion time; the time from the first contact of the teeth to the maximum intercuspidation; reference value in patient with natural teeth <0.2 s; TDL: Disclusion time to the left; the time from the maximum intercuspidation to obtain complete lack of the teeth contact in lateral movement to the left; reference value in patient with natural teeth <0.4 s; TDR: Disclusion time to the right; the time from the maximum intercuspidation to obtain complete lack of the teeth contact in lateral movement to the right; reference value in patient with natural teeth <0.4 s; NHP: Natural head position; μSv: micro-Sievert; kV: kilovolt; mA: miliampere; cm: centimeter; μm: micrometer; s: second; Hz: Hertz; C1-C2: Segment of atlas and axis; AOD: Atlantooccipital dislocation; RV: Reference value; TrP: Trigger point; VAS: Visual Analog Scale; CN V: Cranial nerve V, trigeminal nerve; OC-C1: Occiput and first vertebra junction