BACKGROUND Bruxism is a rhythmic masticatory muscle activity that occurs involuntarily in a non-physiologically functional state.There is a lack of research classifying the functional status of masticatory muscles in ...BACKGROUND Bruxism is a rhythmic masticatory muscle activity that occurs involuntarily in a non-physiologically functional state.There is a lack of research classifying the functional status of masticatory muscles in patients with different mandibular movement types(centric clenching or eccentric grinding)of bruxism.AIM To assess the differences of the masticatory muscle activity in patients with different types of bruxism.METHODS A total of 21 subjects with centric bruxism(CB)and 21 subjects with eccentric bruxism(ECB)were screened from college students according to a questionnaire and their tooth wear features.Sixteen subjects with no bruxism were also recruited.The surface electromyography(EMG)signals of the temporalis anterior(TA)and superficial masseter muscle(MM)were measured in different mandibular positions and during the chewing task.The EMG amplitude and chewing cycle duration parameters were then analyzed.RESULTS The CB group showed fewer muscle maximal motor units,with the MM being more pronounced,a higher proportion of muscle contractions to be recruited for the same load of chewing activity,and a longer chewing cycle.The ECB group showed more TA maximal motor units and higher MM activity on the nonworking side in unilateral chewing.CONCLUSION CB mainly affects the MM,and patients with CB show reduced masticatory muscle contraction efficiency and chewing cycle efficiency.ECB mainly affects the TA,and patients with ECB show enhanced contraction of non-functional lateral muscle bundles.展开更多
Craniofacial muscles are essential components of the skeletal muscular system that contribute to important physiological processes.Severe trauma can induce craniofacial volumetric muscle loss(VML),which impairs muscle...Craniofacial muscles are essential components of the skeletal muscular system that contribute to important physiological processes.Severe trauma can induce craniofacial volumetric muscle loss(VML),which impairs muscle regeneration,causes facial muscular deformities and functional disability,and leads to psychosocial consequences such as isolation and depression.Conventional therapies involving muscle flap transposition or autologous tissue grafting achieve morphological repair but are ineffective in restoring muscle function,resulting in donor site injury and sensory deficit.In this study,we successfully constructed a biomimetically engineered muscle tissue that integrates myofiber alignment,effective innervation,and blood perfusion to promote multi-tissue regeneration in the masseter area in vivo,enabling functional regeneration.Using light-controlled micropatterning technology,we constructed mature muscle fibers with oriented alignment and established a neuromuscular co-culture system for in vitro neuromuscular junction reconstruction.Furthermore,we designed and fabricated a vascular network structure to promote tissue vascularization using hydrogel as the vehicle for assembling the composite engineered tissue.Using this technology,the shape and dimension of the constructed entity can be customized to address various muscle defects,enabling individualized repair.This study offers a promising novel strategy for tissue regeneration that breaks through the current challenges in the treatment of craniofacial VML.展开更多
The purpose of this study was to evaluate the electromyographic (EMG) activity of the masseter and temporalis muscles and the skeletal and dental behavior of children having slow maxillary expansion with a quadhelix a...The purpose of this study was to evaluate the electromyographic (EMG) activity of the masseter and temporalis muscles and the skeletal and dental behavior of children having slow maxillary expansion with a quadhelix appliance. The study sample consisted of 30 children (mean age = 7 years 4 months;17 girls/13 boys) diagnosed with a unilateral posterior crossbite. Lateral cephalometric tracing and EMG analyses were carried out before orthodontic treatment (T1) and 1 month after removal of the appliance (T2). The EMG activity of the masseter and temporalis muscles was analyzed in two clinical situations: at muscular rest and during habitual chewing. Differences in the measurements were evaluated by using paired t tests. Maxillary expansion with the quadhelix appliance did not promote significant anteroposterior and vertical skeletal alterations. Among the cephalometric variables related to dental pattern, only 1-ANS-PNS values presented a significant increase at T2. At muscular rest, EMG analysis indicated a significant increase in the activity of the temporalis muscle. During habitual chewing, EMG activity decreased significantly for both evaluated muscles after removal of the quadhelix appliance. These alterations suggest an adaptation and reprogramming of the musculature to the new occlusal condition.展开更多
Objective: This study was performed with the purpose a report clinical cases involving condylar position and Nóbilo’s sliding plates. Background: Patients may present temporomandibular disorder (TMD), which is c...Objective: This study was performed with the purpose a report clinical cases involving condylar position and Nóbilo’s sliding plates. Background: Patients may present temporomandibular disorder (TMD), which is characterized by pain in masticatory muscles, temporomandibular joints and limited mandible movements. Treatment involving oral rehabilitation with the use of complete dentures with Nóbilo’s sliding plates has been an alternative for the treatment of TMD. Materials and Methods: Nine patients with a history of TMD signs and symptoms (RDC/TMD)—in particular, muscular and articular pain—received pain evaluations, mandibular movement analysis, transcranial radiography and an electromyographic analysis of the masseter and temporalis muscles before and after the use of complete dentures with Nóbilo’s sliding plates. Results: After treatment, the patients had reduced painful symptoms, an increase in mandibular movement and adequate electromyographic activity. The normalized EMG data were ta-bulated and analyzed statistically using SPSS version 17.0 for Windows (SPSS Inc., Chicago, IL, USA), and the values were compared by umpaired independent Student’s t-test. Conclusion: The use of Nóbilo’s sliding plates promoted improvements in electromyographic activity, muscular pain and man-dibular movement.展开更多
文摘BACKGROUND Bruxism is a rhythmic masticatory muscle activity that occurs involuntarily in a non-physiologically functional state.There is a lack of research classifying the functional status of masticatory muscles in patients with different mandibular movement types(centric clenching or eccentric grinding)of bruxism.AIM To assess the differences of the masticatory muscle activity in patients with different types of bruxism.METHODS A total of 21 subjects with centric bruxism(CB)and 21 subjects with eccentric bruxism(ECB)were screened from college students according to a questionnaire and their tooth wear features.Sixteen subjects with no bruxism were also recruited.The surface electromyography(EMG)signals of the temporalis anterior(TA)and superficial masseter muscle(MM)were measured in different mandibular positions and during the chewing task.The EMG amplitude and chewing cycle duration parameters were then analyzed.RESULTS The CB group showed fewer muscle maximal motor units,with the MM being more pronounced,a higher proportion of muscle contractions to be recruited for the same load of chewing activity,and a longer chewing cycle.The ECB group showed more TA maximal motor units and higher MM activity on the nonworking side in unilateral chewing.CONCLUSION CB mainly affects the MM,and patients with CB show reduced masticatory muscle contraction efficiency and chewing cycle efficiency.ECB mainly affects the TA,and patients with ECB show enhanced contraction of non-functional lateral muscle bundles.
基金supported by the National Natural Science Foundation of China(Nos.82122014,82071085,82020108011,and 82301031)the Zhejiang Provincial Natural Science Foundation of China(No.LR21H140001)+2 种基金the National Key Research and Development Program of China(No.2018YFA0703000)the Medical Technology and Education of Zhejiang Province of China(No.2018KY501)the Fundamental Research Funds for the Central Universities(No.2022QZJH55).
文摘Craniofacial muscles are essential components of the skeletal muscular system that contribute to important physiological processes.Severe trauma can induce craniofacial volumetric muscle loss(VML),which impairs muscle regeneration,causes facial muscular deformities and functional disability,and leads to psychosocial consequences such as isolation and depression.Conventional therapies involving muscle flap transposition or autologous tissue grafting achieve morphological repair but are ineffective in restoring muscle function,resulting in donor site injury and sensory deficit.In this study,we successfully constructed a biomimetically engineered muscle tissue that integrates myofiber alignment,effective innervation,and blood perfusion to promote multi-tissue regeneration in the masseter area in vivo,enabling functional regeneration.Using light-controlled micropatterning technology,we constructed mature muscle fibers with oriented alignment and established a neuromuscular co-culture system for in vitro neuromuscular junction reconstruction.Furthermore,we designed and fabricated a vascular network structure to promote tissue vascularization using hydrogel as the vehicle for assembling the composite engineered tissue.Using this technology,the shape and dimension of the constructed entity can be customized to address various muscle defects,enabling individualized repair.This study offers a promising novel strategy for tissue regeneration that breaks through the current challenges in the treatment of craniofacial VML.
基金the Brazilian agencie CAPES for scholarship financial support.
文摘The purpose of this study was to evaluate the electromyographic (EMG) activity of the masseter and temporalis muscles and the skeletal and dental behavior of children having slow maxillary expansion with a quadhelix appliance. The study sample consisted of 30 children (mean age = 7 years 4 months;17 girls/13 boys) diagnosed with a unilateral posterior crossbite. Lateral cephalometric tracing and EMG analyses were carried out before orthodontic treatment (T1) and 1 month after removal of the appliance (T2). The EMG activity of the masseter and temporalis muscles was analyzed in two clinical situations: at muscular rest and during habitual chewing. Differences in the measurements were evaluated by using paired t tests. Maxillary expansion with the quadhelix appliance did not promote significant anteroposterior and vertical skeletal alterations. Among the cephalometric variables related to dental pattern, only 1-ANS-PNS values presented a significant increase at T2. At muscular rest, EMG analysis indicated a significant increase in the activity of the temporalis muscle. During habitual chewing, EMG activity decreased significantly for both evaluated muscles after removal of the quadhelix appliance. These alterations suggest an adaptation and reprogramming of the musculature to the new occlusal condition.
基金This study was supported by the Foundation for Research Support of São Paulo (FAPESP).
文摘Objective: This study was performed with the purpose a report clinical cases involving condylar position and Nóbilo’s sliding plates. Background: Patients may present temporomandibular disorder (TMD), which is characterized by pain in masticatory muscles, temporomandibular joints and limited mandible movements. Treatment involving oral rehabilitation with the use of complete dentures with Nóbilo’s sliding plates has been an alternative for the treatment of TMD. Materials and Methods: Nine patients with a history of TMD signs and symptoms (RDC/TMD)—in particular, muscular and articular pain—received pain evaluations, mandibular movement analysis, transcranial radiography and an electromyographic analysis of the masseter and temporalis muscles before and after the use of complete dentures with Nóbilo’s sliding plates. Results: After treatment, the patients had reduced painful symptoms, an increase in mandibular movement and adequate electromyographic activity. The normalized EMG data were ta-bulated and analyzed statistically using SPSS version 17.0 for Windows (SPSS Inc., Chicago, IL, USA), and the values were compared by umpaired independent Student’s t-test. Conclusion: The use of Nóbilo’s sliding plates promoted improvements in electromyographic activity, muscular pain and man-dibular movement.
