-
Frontiers in Bioengineering and... 2024This study aimed to investigate the selected anatomical factors that can potentially influence temporomandibular joint (TMJ) clicking in young adults by assessing TMJ...
This study aimed to investigate the selected anatomical factors that can potentially influence temporomandibular joint (TMJ) clicking in young adults by assessing TMJ structures and lateral pterygoid muscle (LPM) function using magnetic resonance imaging (MRI). The patients were divided into four groups: the healthy control group; the clicking on mouth opening group; the clicking on mouth closing group; and the clicking on mouth opening and closing group. Additionally, we used clinical palpation to evaluate the masticatory muscles' functional state and employed MRI using the OCOR-T1WI-FSE-CLOSED, OSAG-PDW-FSE-CLOSED, and OSAG-PDW-FSE-OPEN sequences to analyze the texture of the lateral pterygoid muscle (LPM). The proportion of any articular disc or condylar morphology class did not differ significantly between the TMJ clicking and HC groups. The articular disc position did not differ significantly between the TMJ clicking and HC groups. In the TMJ clicking group, the presence of masticatory muscle dysfunction differed significantly between the clicking and non-clicking sides. Moreover, the LPM accounted for the highest proportion among masticatory muscles with tenderness in all TMJ clicking subgroups (77.78%-100%). Therefore, in the TMJ clicking group, the LPM texture was less defined, more uniform in gray scale, and more similar to local texture ( < 0.0001). The occurrence of TMJ clicking in young adults is unrelated to the TMJ structure but related to the function of masticatory muscles, particularly the LPM.
PubMed: 38860136
DOI: 10.3389/fbioe.2024.1337267 -
Neuroradiology Jun 2024This retrospective study examined the clinical outcomes and complications in 6 cases of compound Meige's syndrome, presenting with blepharospasm and masticatory muscle...
This retrospective study examined the clinical outcomes and complications in 6 cases of compound Meige's syndrome, presenting with blepharospasm and masticatory muscle spasm, following treatment with CT-guided radiofrequency ablation targeting bilateral facial nerves and mandibular branches of the trigeminal nerve. After the operation, the symptoms of eyelid spasm and masticatory muscle spasm resolved, but mild facial paralysis and numbness of mandibular nerve innervation persisted. Follow-up for 4-28 months showed that the symptoms of facial paralysis resolved within 2-5 (3.17 ± 0.94) months after the operation, whereas the numbness in the mandibular region persisted, accompanied by a decrease in masticatory function. During the follow-up period, none of the 6 patients experienced a recurrence of Meige's syndrome. These findings suggest that CT-guided radiofrequency ablation of the bilateral facial nerve and mandibular branches of the trigeminal nerve may offer a promising approach to treating compound Meige's syndrome.
PubMed: 38844696
DOI: 10.1007/s00234-024-03392-1 -
Journal of Oral Rehabilitation Jun 2024A quantitative approach to predict expected muscle activity and mandibular movement from non-invasive hard tissue assessments remains unexplored.
BACKGROUND
A quantitative approach to predict expected muscle activity and mandibular movement from non-invasive hard tissue assessments remains unexplored.
OBJECTIVES
This study investigated the predictive potential of normalised muscle activity during various jaw movements combined with temporomandibular joint (TMJ) vibration analyses to predict expected maximum lateral deviation during mouth opening.
METHOD
Sixty-six participants underwent electrognathography (EGN), surface electromyography (EMG) and joint vibration analyses (JVA). They performed maximum mouth opening, lateral excursion and anterior protrusion as jaw movement activities in a single session. Multiple predictive models were trained from synthetic observations generated from the 66 human observations. Muscle function intensity and activity duration were normalised and a decision support system with branching logic was developed to predict lateral deviation. Performance of the models in predicting temporalis, masseter and digastric muscle activity from hard tissue data was evaluated through root mean squared error (RMSE) and mean absolute error.
RESULTS
Temporalis muscle intensity ranged from 0.135 ± 0.056, masseter from 0.111 ± 0.053 and digastric from 0.120 ± 0.051. Muscle activity duration varied with temporalis at 112.23 ± 126.81 ms, masseter at 101.02 ± 121.34 ms and digastric at 168.13 ± 222.82 ms. XGBoost predicted muscle intensity and activity duration and scored an RMSE of 0.03-0.05. Jaw deviations were successfully predicted with a MAE of 0.9 mm.
CONCLUSION
Applying deep learning to EGN, EMG and JVA data can establish a quantifiable relationship between muscles and hard tissue movement within the TMJ complex and can predict jaw deviations.
PubMed: 38840513
DOI: 10.1111/joor.13769 -
Journal of Oral Rehabilitation Jun 2024It remains unclear how the salivary flow and the fat content of food affect bolus formation during mastication.
BACKGROUND
It remains unclear how the salivary flow and the fat content of food affect bolus formation during mastication.
OBJECTIVES
We aimed to clarify: (1) how hyposalivation affects jaw-closing and hyoid-elevating muscle activities in bolus formation, and (2) if the effect of hyposalivation on muscle activity depends on the fat content of food.
METHODS
Eighteen healthy male volunteers were instructed to freely ingest four test foods: Plain, Fat without seasoning, Fat with seasoning, and Soft rice crackers. Masseter and suprahyoid electromyographic activities were recorded before and 30 min after the administration of atropine sulfate, a muscarinic receptor antagonist that induces hyposalivation.
RESULTS
Hyposalivation extended the masticatory duration significantly in all the test foods except Fat with seasoning. Masticatory cycle time was significantly longer with vs without hyposalivation for the Soft (p = .011). Suprahyoid activity/cycle was significantly greater with vs without hyposalivation (p = .013). Masticatory cycle time was significantly longer at the late stage with vs without hyposalivation for the Soft (p < .001). Suprahyoid activity/cycle was significantly greater at the middle (p = .045) and late stages (p = .002) with vs without hyposalivation for the Soft and greater at the late stage with vs without hyposalivation for the Plain (p = .043). Changes in masticatory cycle time and suprahyoid activity/cycle for these foods had significantly positive relationship (p < .001).
CONCLUSION
Hyposalivation-induced changes in masticatory behaviours resulted from the middle and late stage suprahyoid activity. Fat content and seasoning compensate for salivary flow inhibition.
PubMed: 38840501
DOI: 10.1111/joor.13764 -
Journal of Oral Rehabilitation Jun 2024Electromyographic activity (EMG) of masticatory muscles during wakefulness is understudied. It is unclear if single channel ambulatory EMG devices are sensitive enough...
BACKGROUND
Electromyographic activity (EMG) of masticatory muscles during wakefulness is understudied. It is unclear if single channel ambulatory EMG devices are sensitive enough to detect masticatory muscle activity (MMA) during wakefulness.
OBJECTIVES
To compare the MMA of various oral tasks recorded with a single channel EMG device ((Grindcare4-datalogger Prototype device) (GC4-β)) and a conventional EMG (cEMG) device.
METHODS
EMG activity of 30 standardised oral tasks was recorded unilaterally from the masseter and anterior temporalis muscle in 24 healthy volunteers using GC4-β and a cEMG device. To compare the EMG data, signal-to-noise ratios (SNR) were calculated as a way to normalise EMG activity across tasks. Analysis of variance was used to compare the SNR between the devices, muscles and oral tasks.
RESULTS
SNR measured from GC4-β was overall significantly higher than the cEMG device (p =.001). The SNR for maximum voluntary contraction (MVC) was significantly higher than all other tasks (p <.001). SNR for temporalis with GC4-β was significantly higher for MVC, hard food, soft food, gum chewing (dominant side), rhythmic clenching and upper lip biting compared to the cEMG device (p <.021). The SNR for masseter with GC4-β was significantly higher for hard food and gum chewing (dominant side), rhythmic clenching, rhythmic biting of an object and yawning compared to the cEMG device (p <.022).
CONCLUSIONS
This study provides novel insight into the EMG patterns of numerous oral tasks enhancing knowledge of physiological differences between the masticatory muscles. Further, single channel EMG devices can effectively measure the EMG activity of various oral tasks during wakefulness.
PubMed: 38837445
DOI: 10.1111/joor.13714 -
Intelligent bell facial paralysis assessment: a facial recognition model using improved SSD network.Scientific Reports Jun 2024With the continuous progress of technology, the subject of life science plays an increasingly important role, among which the application of artificial intelligence in...
With the continuous progress of technology, the subject of life science plays an increasingly important role, among which the application of artificial intelligence in the medical field has attracted more and more attention. Bell facial palsy, a neurological ailment characterized by facial muscle weakness or paralysis, exerts a profound impact on patients' facial expressions and masticatory abilities, thereby inflicting considerable distress upon their overall quality of life and mental well-being. In this study, we designed a facial attribute recognition model specifically for individuals with Bell's facial palsy. The model utilizes an enhanced SSD network and scientific computing to perform a graded assessment of the patients' condition. By replacing the VGG network with a more efficient backbone, we improved the model's accuracy and significantly reduced its computational burden. The results show that the improved SSD network has an average precision of 87.9% in the classification of light, middle and severe facial palsy, and effectively performs the classification of patients with facial palsy, where scientific calculations also increase the precision of the classification. This is also one of the most significant contributions of this article, which provides intelligent means and objective data for future research on intelligent diagnosis and treatment as well as progressive rehabilitation.
Topics: Humans; Bell Palsy; Neural Networks, Computer; Female; Male; Facial Expression; Adult; Artificial Intelligence; Middle Aged; Facial Paralysis; Facial Recognition; Automated Facial Recognition
PubMed: 38834661
DOI: 10.1038/s41598-024-63478-x -
Journal of International Society of... 2024Temporomandibular joint disorder (TMD), which affects the masticatory muscles, temporomandibular joint, and surrounding tissues, can manifest as inflammation. This study...
AIM
Temporomandibular joint disorder (TMD), which affects the masticatory muscles, temporomandibular joint, and surrounding tissues, can manifest as inflammation. This study aims to explore the expression levels of the inflammatory biomarkers, interleukin (IL)-1β and C-reactive protein (CRP), in TMD patients who have undergone orthodontic treatment.
MATERIALS AND METHODS
Buccal swabs from 105 postorthodontic treatment patients were analyzed using real-time polymerase chain reaction to assess the expression levels of IL-1β and CRP in each group after messenger ribonucleic acid extraction. Patients were also examined using the Diagnostic Criteria for TMD (DC/TMD) to determine if they met the criteria for a TMD diagnosis. The TMD group was subdivided into three categories based on the DC/TMD.
RESULTS
The study included 37 patients who did not develop TMD (group 0) and 68 participants who developed TMD after orthodontic treatment, including 17 with pain-related TMDs (group 1), 29 with intra-articular TMDs (Group 2), and 22 with combined pain-related and intra-articular TMDs (group 3). CRP expression was higher than IL-1β in groups 1 and 2, and IL-1β expression was higher than CRP in group 3. The Kruskal-Wallis test showed that IL-1β and CRP expression levels in groups 1, 2, and 3 were not statistically different. Sex and adult age had considerable effects on the occurrence of TMD in patients after orthodontic treatment.
CONCLUSIONS
Higher IL-1β expression was found in postorthodontic treatment patients with more complex TMD. This study strengthens the evidence of inflammation through IL-1β and CRP expression in individuals with TMD, especially after orthodontic treatment.
PubMed: 38827355
DOI: 10.4103/jispcd.jispcd_197_23 -
The Journal of Prosthetic Dentistry Jun 2024Temporomandibular joint dysfunctions (TMDs) are complex problems affecting the temporomandibular joints (TMJs), masticatory muscles, or both. TMDs are considered muscle...
STATEMENT OF PROBLEM
Temporomandibular joint dysfunctions (TMDs) are complex problems affecting the temporomandibular joints (TMJs), masticatory muscles, or both. TMDs are considered muscle pain caused by contraction and ischemia in the masticatory muscles, but evaluation of the efficacy of pharmacological treatment is lacking.
PURPOSE
The purpose of this clinical study was to evaluate the changes in masticatory muscles, joint space, and main arteries supplying the TMJs after pharmacological therapy in patients with TMDs using ultrasonography (USG).
MATERIAL AND METHODS
The TMJ space, masseter and temporal muscles, temporal superficial artery (TSA), and facial artery (FA) were examined using USG in 30 participants with acute TMD pain before and after 10 days of symptomatic treatment with analgesic and myorelaxant. The bilateral masseter and temporal muscle thicknesses, joint space, and end-diastolic minimum velocity (Ved), minimum end-diastolic minimum velocity (Vmin), peak systolic maximum velocity (Vmax), pulsatility index (PI), and resistance index (RI) values of the TSA and FA were measured and compared before and after pharmacological treatment. The relationship between the masseter muscle thickness and the Ved and Vmin values of the TSA and FA before and after pharmacological treatment was analyzed using the paired sample t test; the relationship between the temporal muscle thickness, TMJ spaces, and Vmax, PI, and RI values of the TSA and FA was analyzed using the Wilcoxon signed-rank test (α=.05).
RESULTS
A significant difference was found between the right temporal muscle thickness before and after medication (P=.01), whereas no statistically significant difference was found in the left temporal muscle thickness (P>.05). A significant difference was found between pretreatment and posttreatment bilateral masseter thicknesses at rest (right P=.014; left P=.004). No statistically significant difference was found in the bilateral joint space or Vmax, Vmin, Ved, PI, and RI values of the TSA and FA before and after treatment (P>.05).
CONCLUSIONS
Pharmacological treatment in participants with acute TMD led to a reduction in masseter and temporal muscle thickness but did not significantly affect joint space and local blood flow. USG is a useful diagnostic tool in the diagnosis and follow-up of TMDs.
PubMed: 38825430
DOI: 10.1016/j.prosdent.2024.04.024 -
PloS One 2024[This corrects the article DOI: 10.1371/journal.pone.0251455.].
[This corrects the article DOI: 10.1371/journal.pone.0251455.].
PubMed: 38820312
DOI: 10.1371/journal.pone.0304880 -
Archives of Oral Biology Aug 2024The aim of this study was to understand the temporal and spatial distribution of canonical endochondral ossification (CEO) and non-canonical endochondral ossification...
OBJECTIVE
The aim of this study was to understand the temporal and spatial distribution of canonical endochondral ossification (CEO) and non-canonical endochondral ossification (NCEO) of the normal growing rat condyle, and to evaluate their histomorphological changes following the simultaneous hypotrophy of the unilateral masticatory closing muscles with botulinum toxin (BTX).
DESIGN
46 rats at postnatal 4 weeks were used for the experiment and euthanized at postnatal 4, 8, and 16 weeks. The right masticatory muscles of rats in experimental group were injected with BTX, the left being injected with saline as a control. The samples were evaluated using 3D morphometric, histological, and immunohistochemical analysis with three-dimensional regional mapping of endochondral ossifications.
RESULTS
The results showed that condylar endochondral ossification changed from CEO to NCEO at the main articulating surface during the experimental period and that the BTX-treated condyle presented a retroclined smaller condyle with an anteriorly-shifted narrower articulating surface. This articulating region showed a thinner layer of the endochondral cells, and a compact distribution of flattened cells. These were related to the load concentration, decreased cellular proliferation with thin cellular layers, reduced extracellular matrix, increased cellular differentiation toward the osteoblastic bone formation, and accelerated transition of the ossification types from CEO to NCEO.
CONCLUSION
The results suggest that endochondral ossification under loading tended to show more NCEO, and that masticatory muscular hypofunction by BTX had deleterious effects on endochondral bone formation and changed the condylar growth vector, resulting in a retroclined, smaller, asymmetrical, and deformed condyle with thin cartilage.
Topics: Animals; Mandibular Condyle; Rats; Osteogenesis; Masticatory Muscles; Rats, Wistar; Botulinum Toxins; Immunohistochemistry; Male; Botulinum Toxins, Type A
PubMed: 38815512
DOI: 10.1016/j.archoralbio.2024.105999