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Data in Brief Jun 2024The data presented in this manuscript describe craniofacial landmark coordinate values, muscle and load moment arm lengths, and mechanical advantage rates for...
The data presented in this manuscript describe craniofacial landmark coordinate values, muscle and load moment arm lengths, and mechanical advantage rates for constructing a three-dimensional model of masticatory muscles. Cone-beam computed tomography scans from 30 subjects (aged 12-19 years, 16 females) were used. Thirty-six craniofacial landmarks were identified. Subsequently, the moment arms for 7 muscles and their corresponding load moment arms at incisor and molar positions were determined. Then, the three-dimensional mechanical advantage for each muscle and tooth position was calculated as the ratio of muscle moment arm to load moment arm. This procedure was repeated three times by a main examiner and once by two other examiners. The Friedman test and the square root of the 'method of moments' variance estimator were used to compare data among examiners and calculate random errors, respectively. Although the values for the craniofacial landmark coordinates and biomechanical variables are very close, differences were found between measurements, especially in the interexaminer comparisons. Values served as the basis for reliability (intraclass correlation coefficient) and errors (average mean of absolute differences) analysis in the research paper titled "A three-dimensional method to calculate mechanical advantage in mandibular function: Intra- and interexaminer reliability study," published in the Journal of Orofacial Orthopedics.
PubMed: 38665154
DOI: 10.1016/j.dib.2024.110402 -
Cureus Mar 2024Facial muscles, particularly those involved in mastication, play a pivotal role in the chewing process. Despite their influence on chewing, these muscles undergo...
BACKGROUND
Facial muscles, particularly those involved in mastication, play a pivotal role in the chewing process. Despite their influence on chewing, these muscles undergo alterations during mastication. Examining the relationship between chewed substances and muscle activity can provide insights into various pathological processes and aid in the development of therapeutic chewing techniques.
AIM
This study aimed to evaluate the impact of different commercially available chewing gums on the activity of key masticatory muscles.
METHOD
Twenty-two participants were recruited for the study. They were instructed to chew four commercially available gums: group 1 comprised sugar gum with a strong flavor; group 2 included gum containing sorbitol; group 3 consisted of gum containing xylitol; and group 4 provided sugar gum with a mild flavor. Electromyogram (EMG) recordings were utilized to assess muscle activity. Various aspects of muscle activity, including chewing time, maximum muscle potential, and coordination between different muscles, were evaluated. Data tabulation and analysis were performed using IBM SPSS software version 23.0 (IBM Corp., Armonk, NY).
RESULT
Analysis revealed that in terms of temporalis symmetry, group 2 exhibited the highest mean deviation, while for masseter symmetry, group 3 demonstrated the highest mean deviation. The total deviation for the temporalis and masseter muscles was 72.16% and 65.55%, respectively, indicating greater symmetry in the temporalis muscle. Additionally, group 3 displayed the highest mean deviation in both left and right-sided synergic activity of the muscles. The total deviation for the right and left sides was 64.34% and 65.67%, respectively.
CONCLUSION
The findings suggest that sugar-free chewing gums elicit increased muscle activity compared to sugar-containing chewing gums. Furthermore, the utilization of calorie-free chewing gums with a firm texture was associated with better-coordinated muscle activity. These results provide valuable insights into the effects of different chewing gums on masticatory muscle function and coordination, which may have implications for therapeutic interventions and oral health management.
PubMed: 38659520
DOI: 10.7759/cureus.56849 -
Cureus Mar 2024Epstein-Barr virus (EBV) can cause follicular conjunctivitis, keratitis, oculoglandular syndrome, meningitis, and encephalitis. We report a 54-year-old Hispanic male who...
Epstein-Barr virus (EBV) can cause follicular conjunctivitis, keratitis, oculoglandular syndrome, meningitis, and encephalitis. We report a 54-year-old Hispanic male who presented with right pupil-involved complete ophthalmoplegia, orbital and masticatory muscle inflammation, trigeminal enhancement, and new corneal infiltrate highly suggestive of EBV. Labwork was negative except for positive EBV polymerase chain reaction (PCR) in serum. Magnetic resonance imaging (MRI) of his brain and orbits with contrast showed enhancement of the right ganglion of the trigeminal nerve, oculomotor nerve, all extraocular muscles in the right orbit, and right masticatory and temporalis muscles and a right subacute lacunar infarct. The patient was diagnosed with encephalitis and orbital-face inflammation secondary to EBV infection. The patient improved with systemic steroids.
PubMed: 38659504
DOI: 10.7759/cureus.56888 -
Head & Face Medicine Apr 2024This study aims to analyze to what extent patients with Marfan syndrome (MFS) are affected by temporomandibular disorders (TMD) and its impact on oral health-related...
BACKGROUND
This study aims to analyze to what extent patients with Marfan syndrome (MFS) are affected by temporomandibular disorders (TMD) and its impact on oral health-related quality of life (OHRQoL). To collect data, an online questionnaire was created to recruit participants from Germany, Austria, and Switzerland through social media and support groups. The questionnaire consists of free-text questions, the German versions of the Oral Health Impact Profile (OHIP-G14), the Depression Anxiety Stress Scale (DASS), and the Graded Chronic Pain Status (GCPS).
RESULTS
A total of 76 participants with diagnosed MFS were included. Of these, 65.8% showed TMD symptoms, the most common being pain or stiffness of the masticatory muscles in the jaw angle (50.0%). Only 14.5% of the participants were already diagnosed with TMD. Of the participants with an increased likelihood of a depression disorder, 76.9% showed TMD symptoms. Of those with a critical score for an anxiety disorder, 90.9% showed TMD symptoms. 73.3% of participants with TMD symptoms reached the critical score for a stress disorder. TMD symptoms were associated with a higher risk for chronic pain. In the median, participants with TMD showed statistically notably higher OHIP-G14 scores than participants without TMD (11.5 [IQR 17] vs. 1 [IQR 3] points, p ≤ 0.001).
CONCLUSION
TMD symptoms had a noticeable impact on OHRQoL in patients with MFS, i.e., chronic pain and psychological impairment. TMD seems underdiagnosed, and more research is needed to prevent the associated chronification of pain and psychological burden to improve the OHRQoL.
Topics: Humans; Marfan Syndrome; Female; Male; Temporomandibular Joint Disorders; Adult; Quality of Life; Germany; Surveys and Questionnaires; Middle Aged; Switzerland; Austria; Young Adult; Oral Health
PubMed: 38659050
DOI: 10.1186/s13005-024-00427-z -
Computer Methods and Programs in... Jun 2024Advanced cases of head and neck cancer involving the mandible often require surgical removal of diseased sections and subsequent replacement with donor bone. During the...
STATEMENT OF PROBLEM
Advanced cases of head and neck cancer involving the mandible often require surgical removal of diseased sections and subsequent replacement with donor bone. During the procedure, the surgeon must make decisions regarding which bones or tissues to resect. This requires balancing tradeoffs related to issues such as surgical access and post-operative function; however, the latter is often difficult to predict, especially given that long-term functionality also depends on the impact of post-operative rehabilitation programs.
PURPOSE
To assist in surgical decision-making, we present an approach for estimating the effects of reconstruction on key aspects of post-operative mandible function.
MATERIAL AND METHODS
We develop dynamic biomechanical models of the reconstructed mandible considering different defect types and validate them using literature data. We use these models to estimate the degree of functionality that might be achieved following post-operative rehabilitation.
RESULTS
We find significant potential for restoring mandibular functionality, even in cases involving large defects. This entails an average trajectory error below 2 mm, bite force comparable to a healthy individual, improved condyle mobility, and a muscle activation change capped at a maximum of 20%.
CONCLUSION
These results suggest significant potential for adaptability in the masticatory system and improved post-operative rehabilitation, leading to greater restoration of jaw function.
Topics: Humans; Mastication; Mandibular Reconstruction; Mandible; Computer Simulation; Biomechanical Phenomena; Bite Force
PubMed: 38640839
DOI: 10.1016/j.cmpb.2024.108174 -
Scientific Reports Apr 2024This study used ultrasonography to compare the thickness and cross-sectional area of the masticatory muscles in patients with temporomandibular joint arthralgia and...
This study used ultrasonography to compare the thickness and cross-sectional area of the masticatory muscles in patients with temporomandibular joint arthralgia and investigated the differences according to sex and the co-occurrence of headache attributed to temporomandibular disorders (HATMD). The observational study comprised 100 consecutive patients with TMJ arthralgia (71 females and 29 males; mean age, 40.01 ± 17.67 years) divided into two groups: Group 1, including 86 patients with arthralgia alone (60 females; 41.15 ± 17.65 years); and Group 2, including 14 patients with concurrent arthralgia and HATMD (11 females; 33.00 ± 16.72 years). The diagnosis of TMJ arthralgia was based on the diagnostic criteria for temporomandibular disorders. The parameters of the masticatory muscles examined by ultrasonography were subjected to statistical analysis. The pain area (2.23 ± 1.75 vs. 5.79 ± 2.39, p-value = 0.002) and visual analog scale (VAS) score (3.41 ± 1.82 vs. 5.57 ± 12.14, p-value = 0.002) were significantly higher in Group 2 than in Group 1. Muscle thickness (12.58 ± 4.24 mm) and cross-sectional area (4.46 ± 2.57 cm) were larger in the masseter muscle than in the other three masticatory muscles (p-value < 0.001). When examining sex-based differences, the thickness and area of the masseter and lower temporalis muscles were significantly larger in males (all p-value < 0.05). The area of the masseter muscle (4.67 ± 2.69 vs. 3.18 ± 0.92, p-value = 0.004) and lower temporalis muscle (3.76 ± 0.95 vs. 3.21 ± 1.02, p-value = 0.049) was significantly smaller in Group 2 than in Group 1. An increase in VAS was significantly negatively correlated with the thickness of the masseter (r = - 0.268) and lower temporalis (r = - 0.215), and the cross-sectional area of the masseter (r = - 0.329) and lower temporalis (r = - 0.293). The masseter and lower temporalis muscles were significantly thinner in females than in males, and their volumes were smaller in patients with TMJ arthralgia and HATMD than in those with TMJ arthralgia alone. HATMD and decreased masseter and lower temporalis muscle volume were associated with increased pain intensity.
Topics: Adult; Female; Humans; Male; Middle Aged; Young Adult; Arthralgia; Electromyography; Headache; Headache Disorders; Masticatory Muscles; Temporomandibular Joint; Temporomandibular Joint Disorders
PubMed: 38637633
DOI: 10.1038/s41598-024-59316-9 -
BMC Oral Health Apr 2024The Coronavirus 2019 disease (COVID-19) caused drastic changes in people's lifestyle that affected TMD characteristics through its physical and psychological influences....
BACKGROUND
The Coronavirus 2019 disease (COVID-19) caused drastic changes in people's lifestyle that affected TMD characteristics through its physical and psychological influences. The aim of this study was to define the clinical and psychological characteristics of a large group of well-defined TMD patients and seek their differences between before and during the COVID-19 pandemic to establish points of care to be emphasized in the post-pandemic era.
METHODS
TMD patients diagnosed by the Diagnostic Criteria for Temporomandibular Disorders (DC/TMD) aged ≥ 18 were analyzed. Samples between September, 2017 to July, 2019 (n = 455) and March, 2021 to June, 2022 (n = 338) were collected to represent before and during COVID-19, respectively. The Graded Chronic Pain Scale (GCPS) and Symptom Checklist-90-Revision (SCL-90-R) were used to evaluate disability levels and psychological status. Clinical indices were compared between COVID periods and factors related to higher pain levels were investigated according to pandemic period.
RESULTS
More patients reported pain on palpation of the masticatory muscles during the pandemic (p = 0.021) while the number decreased for neck muscles (p = 0.001) and TMJ (p < 0.001) areas. Patients reporting nocturnal bruxism (23.3-29.6%) and clenching (45.1-54.7%) significantly increased during the pandemic. TMD patients with pain without disability were more common during the pandemic regardless of pain intensity (p < 0.001). The number of patients expressing interference in daily activities decreased drastically during COVID-19 regardless of disability level (p < 0.001). Factors associated with higher than moderate pain intensity (CPI ≥ 50) were insomnia (odds ratio [OR] = 1.603, p = 0.047) and somatization (OR = 1.082, p < 0.001) before the pandemic. During the pandemic, age (OR = 1.024, p = 0.007), somatization (OR = 1.070, p = 0.006), and paranoid ideation (OR = 1.117, p = 0.003) were significantly associated with higher pain intensity.
CONCLUSIONS
The results of our study underline the importance of evaluating psychological profiles of TMD patients, especially somatization, paranoid ideation and psychoticism, in exceptional situations that may cause a change in individual mental status. This will lead to a better understanding of the individual TMD patient and help in planning personalized treatment strategies that will assist the patient in adjusting to changes occurring in special environments such as the COVID-19 pandemic.
Topics: Humans; COVID-19; Pandemics; Temporomandibular Joint Disorders; Chronic Pain; Life Style
PubMed: 38609928
DOI: 10.1186/s12903-024-04168-y -
Journal of Pharmacy & Bioallied Sciences Feb 2024Various clinical studies performed in adults have shown the relationship between craniofacial morphology and masticatory muscle function. However, the growth of the...
BACKGROUND
Various clinical studies performed in adults have shown the relationship between craniofacial morphology and masticatory muscle function. However, the growth of the masticatory muscle has not received such attention, when compared with the volume of studies on the skeletal growth of face. With this background and considering the widespread use of ultrasonography (USG), the following study was undertaken to provide some insights into the relationship between muscle and bone and facial morphology.
METHODS
This was a prospective, observational study conducted over a period of three years from 2012 to 2015 to assess the correlation between the thickness of the masseter muscle in Angle's normal occlusion and the various malocclusions of the dental arch as well as the facial form. Patients with a full complement set of teeth, normal tooth morphology, Angle's normal occlusion, Angle's class I-III malocclusion, those with a history of third molar extraction, and impaction were included in the study. Those with a history of any prior orthodontic treatment, restorations, or any missing teeth (except the third molar) were exempted from the study. The greater thickness of masseter muscle in relaxed and clenched state was recorded on USG. Facial morphology was determined with the aid of facial photographs.
RESULTS
The study was conducted on 140 patients. The class I normal occlusion group had the thickest masseter muscle, while the class III malocclusion group had the thinnest masseter muscle. Facial parameters showed highly significant gender-wise differences in class I normal occlusion, class I malocclusion, and class II division II malocclusion. There was a significant negative co-relation between the thickness of masseter muscle and facial forms in all the categories of Angle's classification as indicated by a negative regression coefficient B ( < 0.05).
CONCLUSION
The masseter muscle thickness correlated directly with male gender and normal occlusion, and inversely with the degree of malocclusion and facial form.
PubMed: 38595353
DOI: 10.4103/jpbs.jpbs_1112_23 -
Journal of Clinical Medicine Feb 2024Surface electromyography (sEMG) is a technique for measuring and analyzing the electrical signals of muscle activity using electrodes placed on the skin's surface. The... (Review)
Review
Surface electromyography (sEMG) is a technique for measuring and analyzing the electrical signals of muscle activity using electrodes placed on the skin's surface. The aim of this paper was to outline the history of the development and use of surface electromyography in dentistry, to show where research and technical solutions relating to surface electromyography currently lie, and to make recommendations for further research. sEMG is a diagnostic technique that has found significant application in dentistry. The historical section discusses the evolution of sEMG methods and equipment, highlighting how technological advances have influenced the accuracy and applicability of this method in dentistry. The need for standardization of musculoskeletal testing methodology is highlighted and the needed increased technical capabilities of sEMG equipment and the ability to specify parameters (e.g., sampling rates, bandwidth). A higher sampling rate (the recommended may be 2000 Hz or higher in masticatory muscles) allows more accurate recording of changes in the signal, which is essential for accurate analysis of muscle function. Bandwidth is one of the key parameters in sEMG research. Bandwidth determines the range of frequencies effectively recorded by the sEMG system (the recommended frequency limits are usually between 20 Hz and 500 Hz in masticatory muscles). In addition, the increased technical capabilities of sEMG equipment and the ability to specify electromyographic parameters demonstrate the need for a detailed description of selected parameters in the methodological section. This is necessary to maintain the reproducibility of sEMG testing. More high-quality clinical trials are needed in the future.
PubMed: 38592144
DOI: 10.3390/jcm13051328 -
Heliyon Mar 2024This study evaluates masticatory efficiency in orthodontic patients with craniofacial disorders compared to controls without, considering the effect of an orthodontic...
This study evaluates masticatory efficiency in orthodontic patients with craniofacial disorders compared to controls without, considering the effect of an orthodontic appliance and malocclusion. A total of 119 participants (7-21 years), divided into a craniofacial disorder and control group (n = 42 and n = 77; mean age 13.5 ± 5.2 and 14.2 ± 3.3 years) were included. Masticatory efficiency was evaluated using a standard food model test, where masticated test food bodies were analyzed, and parameters like particle number (n) and area (mm) were recorded. This study newly introduced the masticatory efficiency index (MEI), which encompasses the above terms (number and area), with a high MEI being an indicator of high masticatory ability. Younger orthodontic patients with a craniofacial disorder had a significantly decreased MEI (0.50 ± 0.25 n/mm) compared to patients without (1.10 ± 0.48 n/mm; p = 0.02). The presence of a crossbite significantly decreased masticatory efficiency, particularly in craniofacial disorder patients (0.69 ± 1.44 n/mm) versus controls (0.89 ± 1.00 n/mm, p = 0.04). As treatment progressed with age and fixed appliances, mastication group differences became non-significant, suggesting that patients with a craniofacial disorder were catching up to healthy controls in the rehabilitation of their masticatory function. Considering an early diagnosis of malocclusion during orthodontic therapy in combination with speech therapy can avoid negative malocclusion effects with growth, caused by muscle imbalances.
PubMed: 38545195
DOI: 10.1016/j.heliyon.2024.e28321