A simple method for evaluation of tongue position TSUIKI, S.; HANDA, S.; OHYAMA, K.
Journal of oral rehabilitation,
April 2007, 2007-Apr, 2007-04-00, 20070401, Letnik:
34, Številka:
4
Journal Article
Recenzirano
summary Neck extension because of contraction of cervical extensor muscles often brings about a lower‐positioned tongue secondary to jaw opening in patients with congenital myopathy (CM). We ...hypothesized that neck extension in control subjects would reproduce the lower position of the tongue similar to that found in a CM patient. A simple method was formulated to evaluate the tongue position in terms of tongue pressure on the maxillary molar. A pair of pressure sensors was attached to the buccal and lingual surfaces of the upper molar for both the CM patient and four control subjects. Changes in the buccal and tongue pressures were recorded at the neck extension position for the CM patient and during both the natural head position and neck extension for the control subjects. There was a remarkable difference between buccal and tongue pressures in the neck extension position in the CM patient: tongue pressure was not detected at all, indicating there was no contact between tongue and upper molar. The buccal and tongue pressures were approximately equal in the natural head position in the control subjects. However, both buccal and tongue pressures were reduced during neck extension in the control subjects, with a greater decrease in the tongue pressure than the buccal pressure. These findings suggest that neck extension in a control subject reproduces the lower position of the tongue observed in CM patients. We propose that the pressure sensor enables evaluation of the tongue position, but further investigation is required.
: This article presents numerical investigations of the effect of radial gap and volute tongue position on the circumferential pressure distribution and the magnitude of resulting imbalanced radial ...force. A series of volute models was designed using the constant mean velocity method. The results indicate that a radial clearance of 10% is a good practical value that gives a relatively high head across the pump for a small radial force. The results show that the tongue position at 30 degrees gives the lowest radial force and pressure head. The tongue position at 15 degrees appears to give the best compromise results producing a generated head only 5% less than the maximum value while the radial force is about 22% less than the maximum force.
The purpose of this study was to test whether the tongue position affects the electromyographic (EMG) activities of masticatory muscles. We recorded the EMG activities of the masseter and anterior ...temporalis muscles in 10 skeletal Class I adults. Tongue position was monitored by two pressure transducers embedded in the midpalatal region and the lingual flange of a custom-made acrylic monoblock. We instructed subjects to assume three different tongue positions: rest, superior, and anterior. Friedman's test and Sheffe's F-test were used to statistically examine differences in muscle activities induced by changes in tongue position. Significant differences were found in masseter muscle activity between the rest and anterior positions and in anterior temporalis muscle activity between the rest and both the anterior and the superior tongue positions. We concluded that masticatory muscle activity is affected by tongue position.
Objective
The Pierre Robin Sequence (PRS) is a good example of disturbed embryonic development of the secondary palate involving insufficient mandibular growth, failed forward tongue movement, and, ...in the case of a cleft, impeded fusion of the secondary palate. Discussion continues regarding which of the involved pathogenetic factors is the primary cause of the induced cascade of signs: insufficient mandibular growth or failed descent of the tongue.
Design
Forty-five randomly selected, 18-day-old formalin-fixed A/WySn mouse fetuses were investigated. The strain is known to have a basic genetic defect and as much as 44% clefts in the offspring. Twenty-four fetuses in the group had a cleft palate. Mandible position was measured relative to the head and to the presence or absence of a cleft. Cleft width and tongue position were also determined. Thirty-eight NMRI mouse fetuses of the same age served as controls.
Results
All A/WySn fetuses showed marked mandibular retrognathia, which was more severe in the cleft group (p < .05), but there was no correlation between the degree of retrognathia and cleft width. The median cleft width was 3.4 mm (1.6 through 6.3 mm). The tongue was in the cleft in all 12 fetuses with wide clefts (>3.4 mm wide), and free in the oral cavity in the other 12. Tongue position did not influence the degree of retrognathia (p < .05). Moreover, the tongue was free in all fetuses with severe retrognathia.
Conclusion
The results support the primary role of retroposition of the mandible in the development of cardinal symptoms of Pierre Robin Sequence.
We take advantages of abundant text resource on the Internet and information about English phonetics for assisting human teachers to prepare test items for listening and dictation in English. In this ...preliminary exploration, we built an environment in which teachers choose words that they want to have test items for, and teachers compose the final test items based on the test items that are algorithmically generated by our system. The output of the current system indicates that computers can play active roles in assisting the composition of test items, though we have not done a field test over the usability issues.
summary The prevalence of abnormal (retracted) position of the tongue at rest was examined in subjects with varying number of natural lower teeth. The aim of the study was to explore the ...relationship between tongue retraction and state of dentition and to identify potentially related parameters. The resting tongue positions were recorded in subjects partially edentulous in the lower jaw (n = 164) and compared with those met in dentate (n = 57) and completely edentulous participants (n = 84). Potentially related parameters, such as age, sex, duration of edentulism, palate vault and signs of temporomandibular disorders were also recorded. Tongue retraction was observed in a small percentage (12·3%) of the dentate, almost half (45·7%) of the partially edentulous and in the majority (67·8%) of the completely edentulous participants. The number of natural lower teeth correlated with the resting tongue position in the partially edentulous group. The tongue position at rest was also found weakly related to signs of temporomandibular disorders in the dentate group and to the sex and duration of edentulism in the partially edentulous group. It was concluded that the abnormal positioning of the resting tongue is increasingly observed with decreasing number of natural teeth, possibly in accordance with the morphological and functional alterations that result from teeth loss. The presence of a retracted tongue affects the complete denture construction; however, its effect on denture function remains questionable.
Artifacts are electrical activities that are detected along the scalp by an electroencephalography (EEG) but that originate from non-cerebral origin, which often need to be eliminated before further ...processing of EEG signals. Glossokinetic potentials are artifacts related to tongue movements. In this paper we use these glossokinetic artifacts (instead of eliminating them) to automatically detect and classify tongue positions, which is important in developing a tongue-machine interface. We observe that with a specific selection of a few electrode positions, glossokinetic potentials show contralateral patterns, so that the magnitude of potentials is linearly proportional to the tongue positions flicking at the left to the right inside of cheek. We design a simple linear model based on principal component analysis (PCA) to translate glossokinetic potentials into tongue positions. Experiments on cursor control confirm the validity of our method for tongue position detection using glossokinetic potentials.
Past studies have shown that malposition of the tongue is recognized as a major cause of anterior open bite, and many studies have investigated the relationship between open bite and the tongue. ...However, no studies have measured changes of the tongue position for a long period after orthognathic surgery. A new wireless telemeter system was developed to measure the tongue position and head posture in skeletal mandibular prognathism with anterior open bite before and after orthognathic surgery. The purpose of this study was to investigate the mechanism of adaptation of the peri-oral soft tissue to the new jaw relationship that had been reconstructed by orthognathic surgery. Data were obtained presurgically and after a debonding period for three cases whose occlusions were stable, and they were compared with the corresponding data of 23 normal occlusions. The results were as follows: 1) Change in the tongue-contacting area The tongue-contacting area was larger in two cases before orthognathic surgery than that of the normal occlusions. In another case, at the area of the mandible, similar results were obtained, but at the maxilla, the presurgical tongue-contacting area was smaller than that of the normal occlusions. In all cases, the tongue-contacting area before orthognathic surgery became similar to that of normal occlusions by correction of the jaw-relationship and occlusion. 2) Change of head posture In all cases, the head posture was not significantly different from that in normal occlusions. However, the head posture showed a slight backward inclination after orthognathic surgery. The results suggest that head posture and the peri-oral soft tissues, including the tongue, might have adapted to the jaw-relationship and occlusion that is newly reconstructed by orthognathic surgery.
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