Background: Recording jaw movement rhythms in patients with jaw defects is challenging using conventional tracking devices. However, masticatory rhythm is crucial for masticatory performance and nutritional intake. Th...Background: Recording jaw movement rhythms in patients with jaw defects is challenging using conventional tracking devices. However, masticatory rhythm is crucial for masticatory performance and nutritional intake. This study aimed to explore the impact of using a maxillofacial prosthesis to restore masticatory rhythm in mandibulectomy patients with a novel wearable device. Methods: Twelve patients who underwent mandibulectomy and were rehabilitated with maxillofacial prosthesis were recruited. Chewing rate, cycle durations, coefficient of variation of cycle durations (CV), changing times of skin morphology on the back of the ear pinna area (SM), and masticatory performance were measured during gum chewing without and with a denture using a wearable jaw movement rhythm tracking device. A paired t-test and the Pearson correlation coefficient were used for statistical analysis. Results: The chewing rate increased by 8.6 cycles/min with dentures (P P = 0.01). The CV and SM decreased with dentures (P = 0.004 and P = 0.01, respectively). Significant correlations were found between the CV and SM without dentures (P = 0.004). Conclusion: 1. Wearing maxillofacial prostheses can improve masticatory rhythm in patients who undergo mandibulectomy with Eichner B2 occlusal supports. 2. The wearable device is available for measuring masticatory rhythm in patients with jaw defects in clinics. 3. Changing times of the skin morphology on the back of the ear pinna indicate jaw movement stability through a simpler process than the coefficient of variation of cycle durations.展开更多
To investigate whether masticatory fatigue affects the fracture resistance and pattern of lower premolars restored with quartz-fiber post-core and full crown, 44 single rooted lower premolars recently extracted from o...To investigate whether masticatory fatigue affects the fracture resistance and pattern of lower premolars restored with quartz-fiber post-core and full crown, 44 single rooted lower premolars recently extracted from orthodontic patients were divided into two groups of 22 each. The crowns of all teeth were removed and endodontically treated and then restored with quartz-fiber post-core and full crown. Twenty-two teeth in one group were selected randomly and circularly loaded at 45° to the long axis of the teeth of 127.4 N at a 6 Hz frequency, and the other group was not delivered to cyclic loading and considered as control. Subsequently, all teeth in two groups were continually loaded to fail at 45° to the long axis of the teeth at a crosshead speed of 1 mm.min-1. The mean destructive force values were （733.88±254.99） and （869.14±280.26） N for the experimental and the control group, respectively, and no statistically significant differences were found between two groups （P〉O.05）. Bevel fracture and horizontal fracture in the neck of root were the major fracture mode of the specimens. Under the circumstances of this study, it seems that cyclic loading does not affect the fracture strength and pattern of the quartz-fiber post-core-crown complex.展开更多
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
The purpose of this study is to analyse the neuromuscular balance of the masticatory muscles and the influence on the athlete respiratory parameters induced by custom-made mouthguard. Twenty-six athletes (24 males and...The purpose of this study is to analyse the neuromuscular balance of the masticatory muscles and the influence on the athlete respiratory parameters induced by custom-made mouthguard. Twenty-six athletes (24 males and 2 females), of different disciplines, average age of 32.12 ± 12.05, were recruited. Each athlete received a custom-made mouthguard in the Ethylene-Vinyl-Acetate (EVA) thermoplastic material and using surface electromyography, the masseter muscles and the frontal beams of the temporal muscles were analysed, with and without mouthguard. The athletes were then subjected to a medical examination and cardiopulmonary test, in the condition with and without mouthguard. The use of mouthguard caused an improvement of all the electromyographic indexes analysed. In particular, GLOBAL INDEX (p = 0.0021), BAR (p = 0.0005), IMPACT (p = 0.0076) and ASIM (p = 0.0290) showed an enhancement statistically significant. For the cardiopulmonary test indexes as maximum oxygen uptake (VO2max), minute ventilation (VE), breathing reserve (BR), not statistically differences (p > 0.05) were reported. The custom-made mouthguard improved the neuromuscular balance of the masticatory muscles, symmetrizing the masseters and temporalis muscles work. It produced a better balancing distribution of occlusal loads both in the anterior-posterior direction and in the lateral direction and offered the possibility to produce more muscular work. Moreover, it did not constitute an impediment that can significantly disturb the athlete’s breathing during physical activity.展开更多
Objective: This study was analyzed adult individuals rehabilitated with different types of dentures, with the purpose of verifying the effect that different types of denture rehabilitation have on maximal bite force a...Objective: This study was analyzed adult individuals rehabilitated with different types of dentures, with the purpose of verifying the effect that different types of denture rehabilitation have on maximal bite force and masticatory efficiency. The aim of this study is to facilitate diagnosis and prognosis, bringing contributions to the quality and stability of treatments Materials and Methods: Fifty individuals were divided into five groups: one control group with ten dentate individuals and another four groups formed according to the type of rehabilitation treatment. Maximal bite force was recorded on the first molar regions, and masticatory efficiency rates were recorded on the right, left and habitual sides. Results: Data related to the maximal bite force recordings were statistically significant across the analyzed groups [ANOVA for p ≤ 0.01]. The data related to masticatory efficiency rates also showed statistical significance across all groups [ANOVA for p ≤ 0.05] in the three tested conditions [mastication on the right, left and habitual sides]. Conclusion: The group of individuals rehabilitated with implants and single crowns showed greater bite force values and masticatory efficiency rates compared to the other groups, and the treatment with implantsupported mandibular overdenture improved the function compared to conventional complete dentures, thus evincing that the stomatognathic system has different functional behaviors depending on the type of oral rehabilitation.展开更多
Dental implants have restored masticatory function to over 100000000 individuals,yet almost 1000000 implants fail each year due to peri-implantitis,a disease triggered by peri-implant microbial dysbiosis.Our ability t...Dental implants have restored masticatory function to over 100000000 individuals,yet almost 1000000 implants fail each year due to peri-implantitis,a disease triggered by peri-implant microbial dysbiosis.Our ability to prevent and treat peri-implantitis is hampered by a paucity of knowledge of how these biomes are acquired and the factors that engender normobiosis.Therefore,we combined a 3-month interventional study of 15 systemically and periodontally healthy adults with whole genome sequencing,finescale enumeration and graph theoretics to interrogate colonization dynamics in the pristine peri-implant sulcus.We discovered that colonization trajectories of implants differ substantially from adjoining teeth in acquisition of new members and development of functional synergies.Source-tracking algorithms revealed that this niche is initially seeded by bacteria trapped within the coverscrew chamber during implant placement.These pioneer species stably colonize the microbiome and exert a sustained influence on the ecosystem by serving as anchors of influential hubs and by providing functions that enable cell replication and biofilm maturation.Unlike the periodontal microbiome,recruitment of new members to the peri-implant community occurs on nepotistic principles.Maturation is accompanied by a progressive increase in anaerobiosis,however,the predominant functionalities are oxygen-dependent over the 12-weeks.The peri-implant community is easily perturbed following crown placement,but demonstrates remarkable resilience;returning to pre-perturbation states within three weeks.This study highlights important differences in the development of the periodontal and peri-implant ecosystems,and signposts the importance of placing implants in periodontally healthy individuals or following the successful resolution of periodontal disease.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
Masticatory robots are an effective in vitro performance testing device for dental material and mandibular prostheses.A cable-driven linear actuator(CDLA)capable of bidirectional motion is proposed in this study to de...Masticatory robots are an effective in vitro performance testing device for dental material and mandibular prostheses.A cable-driven linear actuator(CDLA)capable of bidirectional motion is proposed in this study to design a masticatory robot that can achieve increasingly human-like chewing motion.The CDLA presents remarkable advantages,such as lightweight and high stiffness structure,in using cable amplification and pulley systems.This work also exploits the proposed CDLA and designs a masticatory robot called Southeast University masticatory robot(SMAR)to solve existing problems,such as bulky driving linkage and position change of the muscle’s origin.Stiffness analysis and performance experiment validate the CDLA’s efficiency,with its stiffness reaching 1379.6 N/mm(number of cable parts n=4),which is 21.4 times the input wire stiffness.Accordingly,the CDLA’s force transmission efficiencies in two directions are 84.5%and 85.9%.Chewing experiments are carried out on the developed masticatory robot to verify whether the CDLA can help SMAR achieve a natural human-like chewing motion and sufficient chewing forces for potential applications in performance tests of dental materials or prostheses.展开更多
The occlusal force and masticatory efficiency in twenty-one patients (mandibular prognathism =11, mandibular retrognathism = 10) undergone sagittal split
BACKGROUND Dentition defect,a common clinical oral disease developed in humans,not only causes masticatory dysfunction and articulation difficulties but also affects facial appearance and increases the burden on the i...BACKGROUND Dentition defect,a common clinical oral disease developed in humans,not only causes masticatory dysfunction and articulation difficulties but also affects facial appearance and increases the burden on the intestinal tract.Restorative treatment is the primary option for this disease.However,traditional restorations have many drawbacks,such as mismatch with the body,low reliability,and incomplete occlusal function recovery.AIM to analyze the efficacy of orthodontics combined with 3D printing guide plate implant restoration in treating patients with dentition defects and its influence on masticatory and phonic functions.METHODS A prospective study was carried out in 86 patients with dentition defects who received implant prosthesis after orthodontic treatment in our hospital between January 2018 and January 2019.Those patients were divided into a control group and an intervention group with 43 patients in each group using a random number table.The control group received traditional implant restoration,whereas the intervention group received 3D printing guide plate implant restoration.Treatment outcomes,cosmetic appearance,dental function,implant deviation,and quality of life were compared between the two groups.RESULTS The overall response rate in the intervention group was significantly higher than that in the control group(95.35%vs 81.40%,χ^(2)=4.071,P=0.044).The number of cases with neatly trimmed cosmetic appearance(χ^(2)=4.497,P=0.034),complete coverage(χ^(2)=4.170,P=0.041),and normal occlusion(χ^(2)=5.512,P=0.019)in the intervention group was higher than that in the control group.After treatment,mastication,swallowing,and articulation were significantly improved in both groups.Masticatory(t=2.980,P=0.004),swallowing(t=2.199,P=0.031),and phonic functions(t=3.950,P=0.004)were better in the intervention group than those in the control group.The deviation value and the deviation angle(t=5.440,P=0.000)at the top(t=6.320,P=0.000)and middle parts of the implants(t=22.295,P=0.000)in the intervention group were lower than those in the control group after treatment.Functional limitations,psychosocial and physical pain and discomfort,and total scores decreased in both groups.The functional limitation(t=2.379,P=0.020),psychosocial(t=2.420,P=0.000),physical pain and discomfort(t=6.581,P=0.000),and total scores(t=2.140,P=0.035)were lower in the intervention group than those in the control group.CONCLUSION Orthodontic treatment combined with 3D printing guide plate implant restoration can significantly improve the masticatory and phonic functions,quality of life,and psychological health of patients with dentition defects.Therefore,it is highly recommended in clinic application.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
The occlusal design plays a decisive role in the fabrication of dental restorations.Dentists and dental technicians depend on mechanical simulations of mandibular movement that are as accurate as possible,in particula...The occlusal design plays a decisive role in the fabrication of dental restorations.Dentists and dental technicians depend on mechanical simulations of mandibular movement that are as accurate as possible,in particular,to produce interference-free yet chewing-efficient dental restorations.For this,kinetic data must be available,i.e.,movements and deformations under the influence of forces and stresses.In the present study,so-called functional data were collected from healthy volunteers to provide consistent information for proper kinetics.For the latter purpose,biting and chewing forces,electrical muscle activity and jaw movements were registered synchronously,and individual magnetic resonance tomograms(MRI)were prepared.The acquired data were then added to a large complex finite element model of the complete masticatory system using the functional information obtained and individual anatomical geometries so that the kinetics of the chewing process and teeth grinding could be realistically simulated.This allows developing algorithms that optimize computer-aided manufacturing of dental prostheses close to occlusion.In this way,a failure-free function of the dental prosthesis can be guaranteed and its damage during usage can be reduced or prevented even including endosseous implants.展开更多
This study aimed to analyze frequencies of flavor detection signals occurring in any of the three respiratory phases and either of the two masticatory phases. Flavors of three fruity (grape, orange, and strawberry) gu...This study aimed to analyze frequencies of flavor detection signals occurring in any of the three respiratory phases and either of the two masticatory phases. Flavors of three fruity (grape, orange, and strawberry) gummy candies in the mouth were detected after chewing in 24 young healthy participants. The results revealed that: 1) more detection signals occurred in the expiratory phase than in the inspiratory or pausing phases and 2) more detection signals occurred in the jaw-closing phase than in the jaw-opening phase. Statistical analysis showed that the difference between the frequencies among the three respiratory phases was significant (P < 0.001) but not between the two masticatory phases. Further analysis showed that the frequencies occurring within individual respiratory phases were not significantly biased. The present results suggest that flavor detection during chewing depends more on the expiratory phase rather than the inspiratory and pausing phases, whereas detection is dependent to a lesser extent on either of the masticatory phases.展开更多
Nowadays mandibular advancement appliances (MA- As) are available and distributed widely in the field of dentistry for the treatment of snoring and ob- structtive sleep apnea (OSA). However, a few stud- ies discussed ...Nowadays mandibular advancement appliances (MA- As) are available and distributed widely in the field of dentistry for the treatment of snoring and ob- structtive sleep apnea (OSA). However, a few stud- ies discussed temporomandibular joint (TMJ) discom- fort and masticatory muscle stiffness during wearing MAAs are found. A new appliance that we introduced in this pilot study has shown significant jaw move- ment and could diminish TMJ and masticatory side effects.展开更多
文摘Background: Recording jaw movement rhythms in patients with jaw defects is challenging using conventional tracking devices. However, masticatory rhythm is crucial for masticatory performance and nutritional intake. This study aimed to explore the impact of using a maxillofacial prosthesis to restore masticatory rhythm in mandibulectomy patients with a novel wearable device. Methods: Twelve patients who underwent mandibulectomy and were rehabilitated with maxillofacial prosthesis were recruited. Chewing rate, cycle durations, coefficient of variation of cycle durations (CV), changing times of skin morphology on the back of the ear pinna area (SM), and masticatory performance were measured during gum chewing without and with a denture using a wearable jaw movement rhythm tracking device. A paired t-test and the Pearson correlation coefficient were used for statistical analysis. Results: The chewing rate increased by 8.6 cycles/min with dentures (P P = 0.01). The CV and SM decreased with dentures (P = 0.004 and P = 0.01, respectively). Significant correlations were found between the CV and SM without dentures (P = 0.004). Conclusion: 1. Wearing maxillofacial prostheses can improve masticatory rhythm in patients who undergo mandibulectomy with Eichner B2 occlusal supports. 2. The wearable device is available for measuring masticatory rhythm in patients with jaw defects in clinics. 3. Changing times of the skin morphology on the back of the ear pinna indicate jaw movement stability through a simpler process than the coefficient of variation of cycle durations.
基金supported by the Guangdong Province Science and Technology Commission (2008B080703019, 2011B080701010 and 2011B080701086)
文摘To investigate whether masticatory fatigue affects the fracture resistance and pattern of lower premolars restored with quartz-fiber post-core and full crown, 44 single rooted lower premolars recently extracted from orthodontic patients were divided into two groups of 22 each. The crowns of all teeth were removed and endodontically treated and then restored with quartz-fiber post-core and full crown. Twenty-two teeth in one group were selected randomly and circularly loaded at 45° to the long axis of the teeth of 127.4 N at a 6 Hz frequency, and the other group was not delivered to cyclic loading and considered as control. Subsequently, all teeth in two groups were continually loaded to fail at 45° to the long axis of the teeth at a crosshead speed of 1 mm.min-1. The mean destructive force values were （733.88±254.99） and （869.14±280.26） N for the experimental and the control group, respectively, and no statistically significant differences were found between two groups （P〉O.05）. Bevel fracture and horizontal fracture in the neck of root were the major fracture mode of the specimens. Under the circumstances of this study, it seems that cyclic loading does not affect the fracture strength and pattern of the quartz-fiber post-core-crown complex.
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.
文摘The purpose of this study is to analyse the neuromuscular balance of the masticatory muscles and the influence on the athlete respiratory parameters induced by custom-made mouthguard. Twenty-six athletes (24 males and 2 females), of different disciplines, average age of 32.12 ± 12.05, were recruited. Each athlete received a custom-made mouthguard in the Ethylene-Vinyl-Acetate (EVA) thermoplastic material and using surface electromyography, the masseter muscles and the frontal beams of the temporal muscles were analysed, with and without mouthguard. The athletes were then subjected to a medical examination and cardiopulmonary test, in the condition with and without mouthguard. The use of mouthguard caused an improvement of all the electromyographic indexes analysed. In particular, GLOBAL INDEX (p = 0.0021), BAR (p = 0.0005), IMPACT (p = 0.0076) and ASIM (p = 0.0290) showed an enhancement statistically significant. For the cardiopulmonary test indexes as maximum oxygen uptake (VO2max), minute ventilation (VE), breathing reserve (BR), not statistically differences (p > 0.05) were reported. The custom-made mouthguard improved the neuromuscular balance of the masticatory muscles, symmetrizing the masseters and temporalis muscles work. It produced a better balancing distribution of occlusal loads both in the anterior-posterior direction and in the lateral direction and offered the possibility to produce more muscular work. Moreover, it did not constitute an impediment that can significantly disturb the athlete’s breathing during physical activity.
基金The authors wish to thank FAPESP(2008/51409-8)for financially supporting this research.
文摘Objective: This study was analyzed adult individuals rehabilitated with different types of dentures, with the purpose of verifying the effect that different types of denture rehabilitation have on maximal bite force and masticatory efficiency. The aim of this study is to facilitate diagnosis and prognosis, bringing contributions to the quality and stability of treatments Materials and Methods: Fifty individuals were divided into five groups: one control group with ten dentate individuals and another four groups formed according to the type of rehabilitation treatment. Maximal bite force was recorded on the first molar regions, and masticatory efficiency rates were recorded on the right, left and habitual sides. Results: Data related to the maximal bite force recordings were statistically significant across the analyzed groups [ANOVA for p ≤ 0.01]. The data related to masticatory efficiency rates also showed statistical significance across all groups [ANOVA for p ≤ 0.05] in the three tested conditions [mastication on the right, left and habitual sides]. Conclusion: The group of individuals rehabilitated with implants and single crowns showed greater bite force values and masticatory efficiency rates compared to the other groups, and the treatment with implantsupported mandibular overdenture improved the function compared to conventional complete dentures, thus evincing that the stomatognathic system has different functional behaviors depending on the type of oral rehabilitation.
基金supported by National Institutes of Health R03DE027492 to Shareef Dabdoubsupported by National Institutes of Health,project number 7R01DE027857-06supported by National Institutes of Health R56DE033913 awarded to Purnima Kumar.
文摘Dental implants have restored masticatory function to over 100000000 individuals,yet almost 1000000 implants fail each year due to peri-implantitis,a disease triggered by peri-implant microbial dysbiosis.Our ability to prevent and treat peri-implantitis is hampered by a paucity of knowledge of how these biomes are acquired and the factors that engender normobiosis.Therefore,we combined a 3-month interventional study of 15 systemically and periodontally healthy adults with whole genome sequencing,finescale enumeration and graph theoretics to interrogate colonization dynamics in the pristine peri-implant sulcus.We discovered that colonization trajectories of implants differ substantially from adjoining teeth in acquisition of new members and development of functional synergies.Source-tracking algorithms revealed that this niche is initially seeded by bacteria trapped within the coverscrew chamber during implant placement.These pioneer species stably colonize the microbiome and exert a sustained influence on the ecosystem by serving as anchors of influential hubs and by providing functions that enable cell replication and biofilm maturation.Unlike the periodontal microbiome,recruitment of new members to the peri-implant community occurs on nepotistic principles.Maturation is accompanied by a progressive increase in anaerobiosis,however,the predominant functionalities are oxygen-dependent over the 12-weeks.The peri-implant community is easily perturbed following crown placement,but demonstrates remarkable resilience;returning to pre-perturbation states within three weeks.This study highlights important differences in the development of the periodontal and peri-implant ecosystems,and signposts the importance of placing implants in periodontally healthy individuals or following the successful resolution of periodontal disease.
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supported by the Natural Science Foundation of Jiangsu Province,China(Grant No.BK20190368)the National Natural Science Foundation of China(Grant No.51705063)the Fundamental Research Funds for the Central Universities,and Zhishan Scholar Program of Southeast University,China.The authors declare no conflictofinterest.
文摘Masticatory robots are an effective in vitro performance testing device for dental material and mandibular prostheses.A cable-driven linear actuator(CDLA)capable of bidirectional motion is proposed in this study to design a masticatory robot that can achieve increasingly human-like chewing motion.The CDLA presents remarkable advantages,such as lightweight and high stiffness structure,in using cable amplification and pulley systems.This work also exploits the proposed CDLA and designs a masticatory robot called Southeast University masticatory robot(SMAR)to solve existing problems,such as bulky driving linkage and position change of the muscle’s origin.Stiffness analysis and performance experiment validate the CDLA’s efficiency,with its stiffness reaching 1379.6 N/mm(number of cable parts n=4),which is 21.4 times the input wire stiffness.Accordingly,the CDLA’s force transmission efficiencies in two directions are 84.5%and 85.9%.Chewing experiments are carried out on the developed masticatory robot to verify whether the CDLA can help SMAR achieve a natural human-like chewing motion and sufficient chewing forces for potential applications in performance tests of dental materials or prostheses.
文摘BACKGROUND Dentition defect,a common clinical oral disease developed in humans,not only causes masticatory dysfunction and articulation difficulties but also affects facial appearance and increases the burden on the intestinal tract.Restorative treatment is the primary option for this disease.However,traditional restorations have many drawbacks,such as mismatch with the body,low reliability,and incomplete occlusal function recovery.AIM to analyze the efficacy of orthodontics combined with 3D printing guide plate implant restoration in treating patients with dentition defects and its influence on masticatory and phonic functions.METHODS A prospective study was carried out in 86 patients with dentition defects who received implant prosthesis after orthodontic treatment in our hospital between January 2018 and January 2019.Those patients were divided into a control group and an intervention group with 43 patients in each group using a random number table.The control group received traditional implant restoration,whereas the intervention group received 3D printing guide plate implant restoration.Treatment outcomes,cosmetic appearance,dental function,implant deviation,and quality of life were compared between the two groups.RESULTS The overall response rate in the intervention group was significantly higher than that in the control group(95.35%vs 81.40%,χ^(2)=4.071,P=0.044).The number of cases with neatly trimmed cosmetic appearance(χ^(2)=4.497,P=0.034),complete coverage(χ^(2)=4.170,P=0.041),and normal occlusion(χ^(2)=5.512,P=0.019)in the intervention group was higher than that in the control group.After treatment,mastication,swallowing,and articulation were significantly improved in both groups.Masticatory(t=2.980,P=0.004),swallowing(t=2.199,P=0.031),and phonic functions(t=3.950,P=0.004)were better in the intervention group than those in the control group.The deviation value and the deviation angle(t=5.440,P=0.000)at the top(t=6.320,P=0.000)and middle parts of the implants(t=22.295,P=0.000)in the intervention group were lower than those in the control group after treatment.Functional limitations,psychosocial and physical pain and discomfort,and total scores decreased in both groups.The functional limitation(t=2.379,P=0.020),psychosocial(t=2.420,P=0.000),physical pain and discomfort(t=6.581,P=0.000),and total scores(t=2.140,P=0.035)were lower in the intervention group than those in the control group.CONCLUSION Orthodontic treatment combined with 3D printing guide plate implant restoration can significantly improve the masticatory and phonic functions,quality of life,and psychological health of patients with dentition defects.Therefore,it is highly recommended in clinic application.
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.
基金We acknowledge the support of the German Research Foundation Grant Nos.SCHM 2456/5-1 and SCHW 307/30-1together with funding for the project initial phase from the German Federal Ministry for Economy and Technology Grant No.KF 2875101WM.(Bundesministerium für Wirtschaft und Technologie)according to a decision of the German Bundestag.
文摘The occlusal design plays a decisive role in the fabrication of dental restorations.Dentists and dental technicians depend on mechanical simulations of mandibular movement that are as accurate as possible,in particular,to produce interference-free yet chewing-efficient dental restorations.For this,kinetic data must be available,i.e.,movements and deformations under the influence of forces and stresses.In the present study,so-called functional data were collected from healthy volunteers to provide consistent information for proper kinetics.For the latter purpose,biting and chewing forces,electrical muscle activity and jaw movements were registered synchronously,and individual magnetic resonance tomograms(MRI)were prepared.The acquired data were then added to a large complex finite element model of the complete masticatory system using the functional information obtained and individual anatomical geometries so that the kinetics of the chewing process and teeth grinding could be realistically simulated.This allows developing algorithms that optimize computer-aided manufacturing of dental prostheses close to occlusion.In this way,a failure-free function of the dental prosthesis can be guaranteed and its damage during usage can be reduced or prevented even including endosseous implants.
文摘This study aimed to analyze frequencies of flavor detection signals occurring in any of the three respiratory phases and either of the two masticatory phases. Flavors of three fruity (grape, orange, and strawberry) gummy candies in the mouth were detected after chewing in 24 young healthy participants. The results revealed that: 1) more detection signals occurred in the expiratory phase than in the inspiratory or pausing phases and 2) more detection signals occurred in the jaw-closing phase than in the jaw-opening phase. Statistical analysis showed that the difference between the frequencies among the three respiratory phases was significant (P < 0.001) but not between the two masticatory phases. Further analysis showed that the frequencies occurring within individual respiratory phases were not significantly biased. The present results suggest that flavor detection during chewing depends more on the expiratory phase rather than the inspiratory and pausing phases, whereas detection is dependent to a lesser extent on either of the masticatory phases.
文摘Nowadays mandibular advancement appliances (MA- As) are available and distributed widely in the field of dentistry for the treatment of snoring and ob- structtive sleep apnea (OSA). However, a few stud- ies discussed temporomandibular joint (TMJ) discom- fort and masticatory muscle stiffness during wearing MAAs are found. A new appliance that we introduced in this pilot study has shown significant jaw move- ment and could diminish TMJ and masticatory side effects.
