Electromyographic evaluation of masseter and anterior temporalis muscles in resting position and during maximum tooth clenching of edentulous patients before and after new complete dentures.
01 Dec 2007-Vol. 20, Iss: 2, pp 67-72
TL;DR: A period longer than five months of wearing the new complete dentures is required for adaptation and the acquisition of functional capacity, and electrical activity during tooth clenching exhibited a statistically significant reduction only in the right temporal muscle.
Abstract: The aim of this study was to assess the electrical activity of the masseter and anterior temporal muscles in patients with severe bone resorption, with complete dentures worn for over ten years, and five months after having new dentures put in place. The RDC questionnaire was applied to twelve asymptomatic patients, before and five months after new dentures were put in place. The electrical activity recordings were made in the mandibular position at rest, and during maximum tooth clenching. The electrical activity of the masseter and anterior temporal muscles in the position at rest presented no statistically significant difference after five months of wearing the new complete dentures. Electrical activity during tooth clenching exhibited a statistically significant reduction only in the right temporal muscle. A period longer than five months of wearing the new complete dentures is required for adaptation and the acquisition of functional capacity.
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TL;DR: The results of this study indicated that 5 months did not allow enough time to demonstrate improved muscular capacity and ability after receiving new dentures, and after 1 year, the duration of the masticatory cycle was reduced, and masticatories efficiency was significantly improved.
Abstract: Sao Paulo State Univ, Dept Dent Mat & Prosthodont, UNESP, BR-16050050 Aracatuba, SP, Brazil
42 citations
TL;DR: The follow-up and professional maintenance of function and hygiene facilitates long-term efficiency in elderly patients and makes the denture insertion an important step of treatment.
Abstract: UNESP Sao Paulo State Univ, Dept Dent Mat & Prosthodont, UNESP Aracatuba Dent Sch, BR-16015050 Sao Paulo, Brazil
21 citations
TL;DR: Comfort and stability improved during the treatment, demonstrated by the QoL and bite force results, and these results are positive for elderly patients who might refuse an implant-supported overdenture due to treatment length.
Abstract: Objectives
The aim of this study was to investigate the outcomes of the installation of two implant-supported overdentures until such treatment is complete. Although this treatment is well established in the literature, there are no studies comparing what happens to muscles and the quality of life (QoL) of patients during the treatment.
Methods
We selected 13 completely edentulous patients, according to inclusion and exclusion criteria, to rehabilitate with mandibular overdentures retained by two dental implants and a complete denture as antagonists. We evaluated the efficacy of the treatment and its evolution in five steps: (i) initially, with the old complete dentures, (ii) after the implants' placement with the mandibular prosthesis relined, (iii) after the placement of the healing abutments, (iv) after the installation and adaptation of new prostheses, and (v) after a 3-month follow-up period. At each stage, we evaluated patients via temporal and masseter electromyography (EMG), molar and incisive bite force, and QoL.
Results
The results for EMG found a decrease in muscle activity during rest, the mastication of raisins, and lateral movements when the overdentures were installed. For the bite force and QoL, there was a gradual improvement from the placement of the healing abutments period (P ˂ 0.05), which was sustained until the follow-up.
Conclusions
Comfort and stability improved during the treatment, demonstrated by the QoL and bite force results. These results are positive for elderly patients who might refuse an implant-supported overdenture due to treatment length.
18 citations
Cites background or result from "Electromyographic evaluation of mas..."
...The muscle activity is lower when the dentures are balanced and steady (Goiato et al. 2007, 2008)....
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...Thus, it has been more commonly reported in studies with longer follow-up periods (Goiato et al. 2007)....
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TL;DR: Electromyographic signals were recorded at rest on both sides, indicating the existence of electric activity of the masseter muscles during swallowing and at rest, and this activity is influenced by the volume of swallowed liquid, and showed significant differences among the tasks.
Abstract: Total laryngectomy is a surgical procedure that can change swallowing biomechanics, including muscle activity of the masseter; this muscle stabilizes the mandible. AIM: To characterize the electrical activity of the masseter muscle during swallowing after total laryngectomy. Series study. MATERIAL AND METHODS: An electromyographic evaluation of swallowing was carried out; three different volumes of water (14.5ml, 20ml and 100ml) were swallowed, and there was a rest condition. The electromyographic signal was normalized by Maximum Resisted Voluntary Activity - considered as 100% of electrical activity of muscles. All other values were calculated as a percentage of this parameter. RESULTS: There is moderate electrical activity of the masseter during swallowing with higher averages on the left. There was no difference between swallowing 14.5ml or 20ml. Natural swallowing of 100ml had the lowest average. Electromyographic signals were recorded at rest on both sides, indicating the existence of electric activity in this situation. CONCLUSION: Patients submitted to total laryngectomy present electrical activity of the masseter muscles during swallowing and at rest. This activity is influenced by the volume of swallowed liquid, and showed significant differences among the tasks. Clinical Trials: NCT01095289
14 citations
TL;DR: Masticator indexes are A/F, and A/t are a very important indicator of the masticatory efficiency and the level of the functional adaptation on complete dentures.
Abstract: BACKGROUND: There are a lot of factors influencing the efficiency of mastication; therefore there are also a lot of methods for testing this efficiency.OBJECTIVE: The study aimed to test the efficiency of mastication and evaluate it in the function of time, based on previous experience with the complete dentures.METHODS: A total of 88 patients (42 female, 46 male, mean age 52.2, SD = 5.76), complete dentures wearers, participated in this study. Masticatory functions were investigated by using the method of electromyography (EMG), analyzing electromyomasticatiogram. For testing the masticator efficiency, the further parameters of the masticatiogram were used: duration of the Standard Masticatory Task (SMT) (t), number of the masticatory cycles within the masticator arch (F) and maximal amplitude within the masticatory arch (F). All data were statistically analysed by using standard software package BMDP (bio-medical Statistical package). Parametric data have been tested using One Way Repeated Measurement of ANOVA test.RESULTS: The changes of the relation A/t are evident in different time intervals in both measured sides: F-DS-time of the measurement = 34.86, P = 0.0000; F-NDS- time of the measurement = 26.1, P = 0.0000. There are also differences of the masticatory index A/t between sexes in both, dominant and non-dominant side: F-DS-gender = 237.05, P = 0.0000; F-NDS-gender = 12.90, P = 0.004. Masticatory index (A/F) varies in time, from first to the sixth measurement in both sides: F-DS-time of the measurement = 32.36, P = 0.0000; F-NDS-time of the measurement = 30.53, P = 0.0000. The interaction of the time and gender was also important: F-DS-interaction = 6.95, P = 0.0000; F-NDS-interaction = 14.9, P = 0.0000.CONCLUSION: Masticator indexes are A/F, and A/t are a very important indicator of the masticatory efficiency and the level of the functional adaptation on complete dentures. Both masticator indexes show the same dynamics (reaching the stationary condition after the 15th week after getting new dentures). After the observing period, all examinee express the same degree of masticator efficiency known as functional adaptation. Patients with previous experience with complete dentures reach faster the stationary condition, compared with those non-experienced.
9 citations
Cites background or methods from "Electromyographic evaluation of mas..."
...A lot of methods are in use for investigating the masticatory efficiency as Fluctuation of the food particles, tested by the system of nets (strainers) with different diameters; Photocolorimetry; Electromyography; Ultrasonography [17]....
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..., [17] concluded that after getting new dentures, the muscular balance of the masticatory system happens, by neuromuscular reprogramming....
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References
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650 citations
"Electromyographic evaluation of mas..." refers result in this paper
...This finding is in keeping with the fact that the masseter muscle is more active in raising the mandible, especially during masticatory function (21, 22), and according to Lippold (23), the mean electrical activities recorded at the surface of the muscles increases with the force of muscular contraction....
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Journal Article•
434 citations
TL;DR: The purpose of the study was to determine the effect of two occlusal schemes on the temporal and masseter muscles and the length of the roots of the canines and the anatomical structure of the supporting alveolar process gives testimony to nature’s intention as to the function intended.
Abstract: 1states: “When canines are in normal interlocking position, the lateral and forward movement is limited so that when an attempt is made to move the mandible laterally or forward, there is an involuntary reaction when the canines come in contact. The reaction is an immediate break in the tension of the temporal and masseter muscles, thus reducing the magnitude of the applied force. Regardless of how hard the individual tries to tense these muscles, as long as the canines are in contact, it is impossible for these muscles to assume full tension.” He continues: “The length of the roots of the canines and the anatomical structure of the supporting alveolar process gives testimony to nature’s intention as to the function intended. What may appear as trauma as they come in contact is not trauma at all, because when contact is made, muscular tension is involuntarily reduced, thus reducing the magnitude of applied force.” The purpose of our study was to determine the effect of two occlusal schemes on the temporal and masseter muscles. The first occlusal scheme used anterior guidance to eliminate all contact of posterior teeth in eccentric movements. The second occlusal scheme allowed selective posterior occlusal contact in eccentric movements. These occlusal schemes were developed using maxillary occlusal splints.
269 citations
"Electromyographic evaluation of mas..." refers background in this paper
...The main function of the temporal muscle is to maintain the mandible against the force of gravity, and it is therefore considered a postural muscle (17, 24-27)....
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TL;DR: Oral function was evaluated in complete denture wearers by using a questionnaire, clinical examination and bite force measurements and the maximal bite force was 5-6 times greater in the dentate subjects than in the Dentate wearers.
Abstract: Oral function was evaluated in complete denture wearers by using a questionnaire, clinical examination and bite force measurements. Ten patients with satisifactory and ten with unsatisfactory dentures were studied and six of the latter patients were reexamined 1 year after the insertion of new dentures. The bite force values were compared with those obtained in ten dentate controls. No significant differences in bite force were found between the satisfactory and unsatisfactory denture groups. Individual values varied much in both groups. The six patients re-examined were satisfied with their new dentures and thought they had improved chewing but no significant increase of bite force was found. The maximal bite force was 5-6 times greater in the dentate subjects than in the denture wearers. Edentulous persons are very handicapped in masticatory function and even clinically satisfactory complete dentures are poor substitutes for natural teeth.
202 citations
TL;DR: In both groups, the peak forces determined from electromyographic activity were larger than the estimated forces required for fragmenting the particles between the teeth.
153 citations
"Electromyographic evaluation of mas..." refers background in this paper
...Several authors state that the main cause of reduction in masseter muscle electrical activity during maximum tooth clenching, also found in the patients of the present study, may be related to the patient’s lack of muscular capacity and ability to adapt to the new complete dentures (24, 34, 36, 4042)....
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...The new denture with correctly positioned cusps, facilitates intercuspidation and demands a lower amount of force to grind the food (33-37)....
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