Diagnostic accuracy of the Pain (P), Enjoyment (E), and General activity (G) scale, a three-item questionnaire, for grading the impact of orofacial pain-related dysfunction.

ABSTRACT: Purpose of this study was to examine the discriminative properties of the 3-item Pain (P), Enjoyment (E), and General activity (G) (PEG) questionnaire for grading impact of nondental orofacial pain. Two hundred eighty-six consecutive patients with orofacial pain of nondental origin filled out the PEG questionnaire and Graded Chronic Pain Scale (GCPS, version 2). Correlation between the PEG and GCPS scores, internal consistency of the PEG, and differences between groups were examined statistically (level of significance: P ≤ 0.05). The mean (±SD) age of the 213 patients (158 female) who were included in the analysis was 43.1 (±16.7) years. Of the sample, 48.8% (n = 104) had some degree of orofacial pain-related disability (mean overall characteristic pain intensity: 51.2 ± 23.2, average overall PEG score: 4.3 ± 2.7, and average PHQ-9 score: 8.2 ± 6.5). No significant differences were found between the sexes for any score. The number of disability points (GCPS) and overall PEG score showed a strong and positive correlation (Spearman ρ = 0.77, P < 0.001). The internal consistency of the PEG questionnaire was high (Cronbach α = 0.86). Assuming 3 different levels of orofacial pain-related disability (mild, moderate, and severe), we obtained overall accuracy of 69.01%, with high specificity for mild and severe cases. The 3 PEG groups (mild, moderate, or severe) differed from each other significantly regarding their clinical grading according to the GCPS (Kruskal-Wallis, P < 0.001). Analysis of the receiver operating characteristic curve showed that a single cutoff value of 3.8 points in the PEG score yields adequate validity (sensitivity = 0.91 and specificity = 0.78). The proposed 2 cutoff points (upper = 7 and lower = 4) yield low sensitivity for the upper threshold. The 3-item PEG questionnaire is suitable for grading impact of nondental orofacial pain.

[Screening for temporomandibular disorders : A sensible approach?] / Screening für kraniomandibuläre Dysfunktionen : Eine sinnvolle Maßnahme?

BACKGROUND: Temporomandibular disorders (TMDs) are typically characterized by pain in the masticatory muscles and temporomandibular joints (TMJs) and by limitation of mandibular mobility. In June 2019, the German Society of Craniomandibular Function and Disorders presented a screening tool to identify individuals with TMDs. The assessment tool consists of patient history (three questions related to jaw pain, one question related to impaired mandibular mobility) and a clinical examination (palpation of masticatory muscles and TMJs; evaluation of maximum jaw opening; assessment of the presence of occlusal disturbances; documentation of TMJ noises). OBJECTIVES: The present article focusses on two questions: (1) Which of the nine parts of the tool are appropriate, and which are not? (2) In general, can screening for TMDs be recommended? CONCLUSION: While the anamnestic questions, as well as the assessment of maximum mandibular opening, reflect the clinically relevant symptoms and signs of TMD patients, the remaining four clinical measures do not. Furthermore, TMD screening for painful TMDs appears unnecessary because patients suffering from orofacial pain and/or restricted mandibular mobility are likely to consult a therapist by themselves. Therefore, the use of this screening tool may lead to overdiagnosis, possibly resulting in nonindicated diagnostic and therapeutic measures.

Three-dimensional amplitude characteristics of masseter motor units and representativeness of extracted motor unit samples.

OBJECTIVE: This study aimed to characterize amplitude topographies for masseter motor units (MUs) three-dimensionally, and to assess whether high-density surface electromyography (HDsEMG) is able to detect MU samples that represent the masseter's entire MU pool. METHODS: Ten healthy adult volunteers participated in the study, which combined three EMG techniques. A HDsEMG grid covering the entire masseter, and intramuscular fine-wire electrodes were used to obtain two independent MU samples for comparison. The MUs' amplitude profiles in the dimension of muscle depth were determined using scanning EMG. All data were recorded simultaneously during a low, constant contraction level controlled by 3D force feedback. RESULTS: The median medio-lateral diameter of 4.4 mm (range: 1.2-7.9 mm) for MUs detected by HDsEMG did not differ significantly (Mann-Whitney-U test, p = 0.805) from that of 3.9 mm (0.6-8.6 mm) for MUs detected by fine-wire EMG. For individual subjects, the medio-lateral diameters of all HDsEMG-detected MUs spanned 70.5% (19.2-75.1%) of the masseter's thickness. CONCLUSIONS: HDsEMG is able to examine small and large MUs from a great masseter proportion in one single measurement. SIGNIFICANCE: Clinical application of HDsEMG might contribute to a better understanding of neuromuscular adaptations in patients with temporomandibular disorders (TMD) and could allow for monitoring treatment effects.

Chronic stress and temporalis muscle activity in TMD patients and controls during sleep: a pilot study in females.

OBJECTIVES: The aim of this study was to assess the correlation between chronic stress and temporalis muscle activity during four nights. MATERIAL AND METHODS: Forty-four female subjects were recruited in five dental practices located in different areas of the federal state of Saarland, Germany (dental practice network in Saarland). The following inclusion criteria were used: female, aged between 18 and 65, no somatization or depression, and no pain medication, graded chronic pain status < 3. Both subjects reporting about sleep bruxism and subjects negating sleep bruxism during anamnesis were included. Anamnestic issues, sleep bruxism, anxiety, and chronic stress were assessed using validated questionnaires. Temporalis muscle activity was measured for four nights using a portable electromyographic device. Correlation coefficient was used to assess the correlation (Spearman-correlation) between chronic stress and number of temporalis muscle episodes/hour and between anxiety and the number of episodes/hour. RESULTS: The analysis showed that the factors "work overload" (adulthood chronic stress because of too many demands at work) and "pressure to perform" (necessity to be successful at work) were significantly correlated with the number of temporalis muscle episodes per hour. In contrast, anxiety was not correlated with temporalis muscle episodes per hour. CONCLUSIONS: Work-related chronic stress seems to be associated with an increased level of temporalis muscle activity during sleep. CLINICAL RELEVANCE: During anamnesis, work-related aspects should be assessed in females presenting with sleep-bruxism.

Effects of occlusal modifications on the muscular activity of the masseter and anterior temporalis muscles.

The aim of this study was to analyze the effect of occlusal modifications on the muscular activity of the masseter and anterior temporalis muscles. The study included 41 healthy dentate subjects who were examined in relation to the muscle activity of the masseter and anterior temporalis muscles recorded by surface electromyography (EMG) bilaterally in two different sessions. Occlusal plastic strips (thickness: 0.4 or 0.8 mm) were placed on different mandibular teeth to simulate different bite constellations (unilateral, bilateral transversal, and bilateral diagonal). Controlled by visual feedback, the subjects performed submaximum occlusion at 10% and 35% of maximum voluntary contraction (MVC). The activity ratios of the muscles were analyzed by two-way repeated measurement analysis of variance (ANOVA), and the reliability of muscle activity data was determined by intraclass correlation coefficient (ICC) analysis. The activity ratios of the masseter muscles were not significantly different under various biting conditions. In contrast, the anterior temporalis muscles showed significant differences (P < 0.001) between unilateral configurations and the other biting conditions (bilateral transversal or diagonal), in particular during biting at 10% MVC. In general, ICC values revealed low to moderate reliability of the measurements of muscle activity. Under controlled submaximum occlusal loading, the activity behavior of the masseter muscles remained stable, whereas the anterior temporalis muscles reacted differently to distinct occlusal biting configurations. The results support the assumption that the anterior temporalis muscles might operate as fine-tuning muscles when asymmetric bite force distributions occur, for instance during chewing, caused by food fragments between the teeth.

Adaptation to new complete dentures-is the neuromuscular system outcome-oriented or effort-oriented?

OBJECTIVE: The aim of this study was to observe the adaptation strategy of the stomatognathic system during the adaptation of complete dentures, comprising masticatory parameters and subjective measures. Our hypothesis was that with new dentures, masticatory performance would increase while the effort of the system is kept constant. MATERIAL AND METHODS: Thirty-two patients received standardized new complete dentures. Masticatory performance tests were conducted with old dentures (T1), immediately after incorporation of new dentures (T2) and after an adaptation period of 3 months (T3). Patients habitually chewed the silicone-based artificial test food Optocal. The comminuted test food was analyzed and mean particle sizes (x50) were calculated. Simultaneously, surface EMGs of the anterior temporalis and masseter muscles were recorded. Specific (SMW) and total muscle work (TMW) were determined. Patients filled in the OHIP-49 questionnaire. Test conditions were compared using repeated-measures ANOVA with SPSS 22 (SPSS Inc.) RESULTS: Masticatory performance increased (P = 0.016) between old (x50 = 4.99 ± 0.28) and adapted new dentures (x50 = 4.80 ± 0.33). TMW deteriorated (P = 0.004) at T2 (from TMW1 = 119.77 ± 56.49 to TMW2 = 92.12 46.27), and increased again (P = 0.028) at T3 (TMW3 = 107.66 ± 44.65). OHIP scores decreased significantly in all subscales (P < 0.001…P = 0.046); the total score was reduced (P < 0.001) from 56.24 ± 29.05 (T1) to 34.66 ± 24.74 (T3). CONCLUSION: In complete denture wearers, masticatory performance improves over an adaptation period. Muscle work initially decreased before reaching its original level again after adaptation. Subjective parameters overestimated the functional improvements. CLINICAL SIGNIFICANCE: The subjective evaluation does not adequately reflect functional improvements. The assessment of function requires an adaptation period.

Quantitative sensory response of the SCM muscle on sustained low level activation simulating co-contractions during bruxing.

OBJECTIVE: Bruxism is discussed as an etiological factor in the pathogenesis of orofacial and cervical pain. As the sternocleidomastoid muscle (SCM) is co-activated during clenching, our aim was to investigate, whether the muscle loading leads to peripheral or central sensitizations. DESIGN: In twenty-one healthy female volunteers, somatosensory profiles of the SCM were recorded according to the test battery of the German Research Network on Neuropathic Pain (DFNS) prior to and after an isometric muscle exercise. QST comprised thermal and mechanical stimuli. A submaximal activation of the SCM (15% MVC) was kept for 10min in sitting position. In separate test sessions one month apart, one sham and one verum experiment were conducted in randomized order. During the muscle loading, the parameters cold detection threshold (CDT), mechanical pain sensitivity (MPS) and pressure pain treshold (PPT) were tested and experimental pain recorded by visual analogoue scales (VAS). All test sessions were performed during the follicular phase of the menstrual cycle (day 5), to avoid effects on pain perception. Data were analyzed with Repeated Measures ANOVA (SPSS 22.0) RESULTS: No significant changes were found during or after (sham) loading except for stimulus-response-function (SR, P=0.01) and PPT (P=0.02) in the sham test. No effect was observed in the verum experiment (P=0.12 up to 1.0). CONCLUSION: Prolonged low level contraction of the SCM does not evoke painful sensitization. In contrast, submaximal muscle activation seems to have a protective effect corresponding to a training effect preventing sensitization.

Functional adaptation of the masticatory system to implant-supported mandibular overdentures.

OBJECTIVES: The purpose of this study was to investigate the adaptation behavior of the stomatognathic system after immediate loading (24 to 72 h after surgery) of two implants supporting mandibular overdentures, assessed on insertion and three months later. The study hypothesis was that insertion of the overdentures would significantly change masticatory performance and muscle activity at both times. MATERIAL AND METHODS: Thirty subjects (nine female, mean age 69.64 ± 11.81 years; 21 male, mean age 68.67 ± 7.41 years) who participated in a randomized clinical trial were included in the study. Each patient was examined three times: (i) at baseline, after already having worn new dentures for three months (T1); (ii) immediately after insertion of the overdentures on the implants (T2); and (iii) after an adaptation period of three months (T3). Examination comprised assessment of masticatory performance with artificial test food (Optocal), and simultaneous bilateral surface EMG recording of the masseter and anterior temporalis muscles. Particle-size distribution (representative value X50 ), maximum muscle contraction (MVC), and total muscle work (TMW; area under the curve) were compared by use of repeated-measures analysis of variance (ANOVA). RESULTS: At T3, all measured variables (i.e., masticatory performance and muscle activity) were significantly different from those at T1. At T2, no significant changes were observed. The study hypothesis had to be rejected for T2 but accepted for T3. CONCLUSION: Functional rehabilitation (in terms of masticatory performance and masticatory muscle activity) does not occur immediately after immediate loading of two implants with mandibular overdentures, but requires a significant time for functional improvement.

Motion analysis of the mandible: guidelines for standardized analysis of computer-assisted recording of condylar movements.

Mandibular movement recording has long been established as the method for the physiological design of indirect dental restorations. Condylar movement recording is the basis for individual, patient-specific programming of partially or fully adjustable articulators. The settings derived from these recordings can generally be used in both traditional mechanical and electronic virtual articulators. For many years, condylar movement recordings have also provided useful information about morphological conditions in the temporomandibular joints (TMJs) of patients with masticatory system dysfunction based on the recorded movement patterns. The latest clinical application for recorded jaw-motion analysis data consists of functional monitoring of the patient as a diagnostic and surveillance tool accompanying treatment. Published parameters for the analysis of such recordings already exist, but a standardized and practicable protocol for the documentation and analysis of such jaw-movement recordings is still lacking. The aim of this article by a multicenter consortium of authors is to provide an appropriate protocol with the documentation criteria needed to meet the requirements for standardized analysis of computer-assisted recording of condylar movements in the future.

Sleep-associated aspects of myofascial pain in the orofacial area among Temporomandibular Disorder patients and controls.

STUDY OBJECTIVES: To assess sleep-associated aspects of temporomandibular disorder (TMD) with myofascial pain (MP) in the orofacial area of patients and controls. MEASUREMENTS: Three hundred five female patients were screened to find 44 participants fulfilling the inclusion criteria, 22 suffering from MP and 22 in a control group. Sleep quality was assessed by use of the Pittsburgh Sleep-Quality-Index (PSQI) and a validated German sleep questionnaire (SF-AR). Tooth wear was assessed and anterior temporalis muscle activity was measured at home for several nights by use of a portable electromyography (EMG) device. RESULTS: 22 patients (45.0 ± 13.6 years) and 22 controls (45.2 ± 9.0 years) were recruited. The PSQI sum-score was 7.5 ± 3.7 for patients and 4.4 ± 3.0 for controls (p = 0.006). The SF-AR showed that 23% of the controls and 14% of the patients were "long sleepers". The overall number of episodes in the two groups was not significantly different (4.10 ± 2.65 versus 4.57 ± 1.99 episodes per hour). However, more patients had temporalis muscle activity possibly related to SB during all four consecutive nights (p = 0.04). According to the International Classification of Sleep Disorders - Third Edition (ICSD-3) criteria, 13.6% of the controls and 71.4% of the patients (p < 0.001) showed SB. CONCLUSIONS: Sleep-associated disturbances, including reduction of sleep quality and greater prevalence of SB and facial pain in the morning, occurred significantly more often among TMD patients. Additionally, SB fluctuated over the nights especially in controls. This should be taken into consideration when the prevalence of SB is assessed by use of EMG.

[Temporomandibular disorders: Evaluation of the usefulness of a self-test questionnaire]. / Kraniomandibuläre Dysfunktionen: Überprüfung der Eignung eines Selbsttest-Fragebogens.

BACKGROUND: A self-test questionnaire has been provided in the internet and in some dental offices for some time now. By using this questionnaire, interested individuals may assess whether they have a temporomandibular disorder (TMD) which might require therapy. It is the aim of this article to examine whether the 11 questions are apt to reliably identify patients with suspected TMDs within a given population. METHODS: Each question has been examined for its relevance by resorting to the current literature. Accordingly, the inclusion of each question into the self-test questionnaire has been rated as suitable or unsuitable. RESULTS: Only 2½ of the 11 questions are useful to detect individuals with as-yet undiagnosed TMDs. CONCLUSIONS: Due to its missing content validity, the questionnaire cannot be recommended.

[Vertical and horizontal jaw relations in reconstructive dentistry. A critical review]. / Vertikale und horizontale Kieferrelation in der rekonstruktiven Zahnmedizin. Eine kritische Literaturübersicht.

Despite comprising one of the routine duties of dental practitioners, the methods used for the determination of the vertical and horizontal jaw position differ considerably from dentist to dentist. For the overwhelming majority of patients, however, the techniques generally applied for the maxillomandibular relationship record appear to lead to acceptable results. No method seems to be clearly superior to the other. As far as the determination of the horizontal mandibular position (centric relation interocclusal record) is concerned, bimanual manipulation has shown to be particularly reliable. The decisive factor, apart from any preferred method, is that the chosen therapeutic mandibular position be reproducible for both the treatment provider as well as the patient.

[Relationship between occlusion and myoarthropathy. Introduction of an integrating neurobiological model]. / Zum Zusammenhang zwischen Okklusion und Myoarthropathien. Einführung eines integrierenden neurobiologischen Modells.

For many decades, the relationship between occlusal factors and temporomandibular disorders has been discussed controversially in the dental literature. After a brief description of current points of view about this topic, a recently published clinical trial by Le Bell et al. (2002) is summarized. The results of this study are discussed on the basis of a novel neurobiologic model, which is based on the heterogeneous activation of the masticatory musculature. This model appears to be suitable to explain the pathogenic and therapeutic effects due to occlusal management of patients with myofascial facial pain.