Tongue pressure and maxillofacial muscle activities during swallowing in patients with mandibular prognathism.

BACKGROUND: Coordination among lip, cheek and tongue movements during swallowing in patients with mandibular prognathism remains unclear. OBJECTIVES: This study aimed to identify the temporal sequences of tongue pressure and maxillofacial muscle activities during swallowing in patients with mandibular prognathism and compared characteristics with those of healthy volunteers. METHODS: Seven patients with mandibular prognathism (mandibular prognathism group) and 25 healthy volunteers with individual normal occlusion (control group) were recruited. Tongue pressures and masseter, orbicularis oris, mentalis and supra- and infrahyoid muscle activities while swallowing gel were measured simultaneously using a sensor sheet system with five measurement points and surface electromyography, respectively. Onset time, offset time and durations of tongue pressure and muscle activities were analysed. RESULTS: In the mandibular prognathism group, tongue pressure was often produced first in more peripheral parts of the palate. Offset of tongue pressure in the posteromedian and peripheral parts of the palate and maxillofacial muscle activities except for orbicularis oris were delayed. Duration of tongue pressure in the anteromedian part of the palate was significantly shorter and durations of masseter, mentalis and suprahyoid muscle activities were significantly longer. Times to onset of orbicularis oris and suprahyoid muscle activities based on first onset of tongue pressure were significantly shorter. CONCLUSION: These results suggest that patients with mandibular prognathism may exhibit specific patterns of tongue pressure production and maxillofacial muscle activities during swallowing.

Modulation of tongue motion and tongue pressure during liquid swallowing with different bolus volumes.

BACKGROUND: The tongue functions by modulating according to bolus volume when swallowing; however, associated tongue dynamics are unclear. OBJECTIVE: We aimed to clarify how tongue motion and tongue pressure change with bolus volume during swallowing. METHODS: Sixteen healthy volunteers (age 29.5 ± 3.8 years; 12 males, 4 females) were recruited. Two electromagnetic articulography markers were attached, one each on the anterior and posterior parts of the tongue, to measure motion. A sensor sheet, with five pressure-sensitive points, was attached to the hard palate to measure tongue pressure. Participants were asked to swallow 3 ml and 10 ml of water. Motion trajectory, maximum velocity, vertical displacement just before contact with the hard palate, and maximum magnitude and duration of tongue pressure were analysed. RESULTS: Tongue rotation was observed in the sagittal plane; its rate of appearance was significantly higher when swallowing 3 ml of water than when swallowing 10 ml, and the rate of rotation at posterior part was significantly higher than at the anterior part. The maximum velocity and vertical displacement were significantly greater when swallowing 10 ml of water than those when swallowing 3 ml of water. There was no significant difference in either the maximum magnitude of tongue pressure or maximum duration of tongue pressure between 3 ml and 10 ml. CONCLUSION: Bolus volume influenced the pattern of tongue motion; however, there was no difference in tongue pressure.

Update and review of the gerodontology prospective for 2020's: Linking the interactions of oral (hypo)-functions to health vs. systemic diseases.

New lines of evidence suggest that the oral-systemic medical links and oral hypo-function are progressively transcending beyond the traditional clinical signs and symptoms of oral diseases. Research into the dysbiotic microbiome, host immune/inflammatory regulations and patho-physiologic changes and subsequent adaptations through the oral-systemic measures under ageism points to pathways leading to mastication deficiency, dysphagia, signature brain activities for (neuro)-cognition circuitries, dementia and certain cancers of the digestive system as well. Therefore, the coming era of oral health-linked systemic disorders will likely reshape the future of diagnostics in oral geriatrics, treatment modalities and professional therapies in clinical disciplines. In parallel to these highlights, a recent international symposium was jointly held by the International Association of Gerontology and Geriatrics (IAGG), Japanese Society of Gerodontology (JSG), the representative of USA and Taiwan Academy of Geriatric Dentistry (TAGD) on Oct 25th, 2019. Herein, specific notes are briefly addressed and updated for a summative prospective from this symposium and the recent literature.

Coordination between lingual motion and pressure production during dipper/tipper type swallows.

BACKGROUND: Tongue motor biomechanics during swallowing was not fully elucidated due to the technical difficulty. OBJECTIVE: To evaluate the relationship between tongue motion and tongue pressure production by simultaneously measuring tongue motion and tongue pressure during water swallowing. METHODS: In 12 healthy male participants (mean age, 30.8 ± 4.2 years), tongue pressure and tongue motion trajectory during dipper- and tipper-type swallows of 3 mL of water were measured using a sensor sheet system equipped with five sensing points and an electromagnetic articulography, respectively. The temporal correlation between motion of anterior/posterior tongue and tongue pressure production during swallowing was evaluated on the synchronised waveforms. RESULTS: In the dipper-type swallow, a similar up-and-down motion pattern in vertical direction was observed among all participants before tongue pressure production. Those motion patterns were common at the anterior and posterior tongue locations with a temporal difference in some segment of tongue motion. On the other hand, tongue directly attached to hard palate with temporal synchronicity between the anterior and posterior parts. In both types of swallow, a strong temporal correlation was found between the timing of tongue-palate contact and the Onset of tongue pressure by intra-class correlation coefficients. CONCLUSION: From the simultaneous measurement of tongue motion and tongue pressure production, the tongue motion pattern during water swallowing and the temporal correlation between tongue motion and tongue pressure production were elucidated.

Evaluation of hyoid movement during swallowing using a bend sensor.

BACKGROUND: Movement of the hyoid and laryngeal complex is critical for preventing aspiration, as well as smooth bolus passage through the pharynx. We have developed a non-invasive system for measuring laryngeal movement during swallowing with a bend sensor and have already reported the time coordination between the signal waveform from the sensor and hyoid movement. OBJECTIVE: The aim of this study was to clarify the quantitative association between the output value of the sensor and hyoid movement during swallowing. METHODS: A small bend sensor was fixed on the skin surface along the midline of the neck of 13 healthy men (mean age, 30.8 ± 4.5 years). Laryngeal and hyoid movements during swallowing of 5 mL of water were recorded synchronously by the bend sensor and videofluorography. The relationship between the bend sensor output value (LM value) and hyoid position (x- and y-axis displacements) by videofluorography from the onset to the offset of the signal waveform was analysed for all tasks and for each task using Pearson's correlation coefficients. RESULTS: There was a positive correlation between the LM value and hyoid position for all tasks (x-axis displacement: r = .647, y-axis displacement: r = .233). In particular, there was a moderate to high correlation between the LM value and x-axis displacement for each task (.453 ≤ r ≤ .934). CONCLUSION: The LM value can be a quantitative parameter of anterior hyoid movement during swallowing that might be associated with bolus flow and upper oesophageal sphincter opening.

Influence of food adhesivity and quantity in lip closing pressure.

Lip closing is an important motor act in food acquisition. Appropriate food capture in anticipatory and early oral stages of feeding is essential for mastication and swallowing. The aim of this study was to investigate the effect of food type and quantity on lip closing pressure during food capture with a spoon, and to identify normal lip function during food acquisition in healthy young adults. Twenty young healthy males (age range: 22-30 years) participated in this study. They were asked to eat the test food freely with a spoon. Test foods were yogurt and cream cheese, which were given in quantities of 3, 5 and 10 g in weight; 3 ml water was included as a reference. A strain gauge transducer was embedded in the spoon in advance, and lip closing pressures during food capture were measured and recorded. The Vicon motion analysis system was used to collect three-dimensional kinematic data of spoon operation. Positive pressure with lip closing during capture of adhesive food, such as cream cheese, significantly increased (P < 0.001). Moreover, positive pressure significantly decreased when food quantity increased (P < 0.01), irrespective of food type. Negative pressure that preceded positive pressure appeared more frequently during cream cheese intake and increased when food quantity on the spoon increased (P < 0.001). These findings indicated that participants sucked or squeezed the spoon further during capture of adhesive food. Maximum mouth opening occurred predominantly during the spoon insertion period, while mouth closing occurred predominantly during the spoon withdrawal period. After mouth closing, all subsequent lip pressure events appeared in the withdrawal period. Our results may be useful for comprehending normal lip function during food acquisition in healthy young adults. They may also aid in the diagnosis and management of abnormal lip function in oral hypofunction and dysfunction, which can be examined in future studies.

The effect of tongue thrusting on tongue pressure production during swallowing in adult anterior open bite cases.

BACKGROUND: Tongue thrusting, which often occurs during swallowing in patients with anterior open bite, is considered to show different tongue dynamics from healthy individuals, but the details are still unclear. OBJECTIVE: This study aimed to identify the effect of tongue thrusting on tongue pressure production during swallowing in patients with anterior open bite. METHODS: The subjects were 11 patients with an anterior open bite and 8 healthy volunteers with individual normal occlusion. The patients were divided into a tongue-thrusting group (n = 8) and a non-thrusting group (n = 3). Tongue pressures while swallowing jelly (4 mL) were recorded by a sensor sheet system with five measuring points (Chs1-5) attached to the palatal mucosa. The time sequences, maximum magnitude and duration of tongue pressure, and swallowing time of tongue pressure were analysed. RESULTS: Tongue pressure waveforms in the tongue-thrusting group were quite diverse compared with the other two groups. The duration at the posterior-median part in the tongue-thrusting group was significantly shorter, and the maximum magnitudes at the mid-median, posterior-median and the peripheral part were also significantly lower than in the healthy group. These results suggest that the compensatory tongue thrust action by which the tongue closes the front part of the oral cavity may make it difficult to lift the tongue and transfer the bolus. CONCLUSION: Patients with an anterior open bite and tongue thrusting at swallowing showed diversity of tongue pressure waveforms and noticeably weaker tongue pressures from mid-median to posterior-median regions than healthy individuals.

Tongue Pressure Measurement and Videofluoroscopic Study of Swallowing in Patients with Parkinson's Disease.

This study investigated the relationship between tongue pressure during swallowing and dysphagia in patients with Parkinson's disease (PD). A total of 24 patients with PD (12 men and 12 women, mean age 70.4 years) were studied. Their mean Hoehn and Yahr scale was 3.0 ± 1.3 (range 1-5). All participants underwent tongue pressure measurement and videofluorography during swallowing. Tongue pressure when swallowing 5 mL of barium on videofluorography was measured using a sensor sheet with five sensors. Based on the findings of videofluorography, the patients were divided into two groups: dysphagic PD group (n = 9) and non-dysphagic PD group (n = 15). The maximal magnitude (kPa), duration (s), time to peak pressure (s), and pressure gradient (kPa/s) of tongue pressure were analyzed for each part. For duration, time to peak pressure, and pressure gradient, similar values were calculated from the total waveform. There was no significant difference in maximal tongue pressure between the groups. The dysphagic PD group had prolonged duration of tongue pressure and time to peak pressure and a reduced pressure gradient compared with the non-dysphagic PD group. These results indicate that there is a clear difference in the temporal aspects of tongue pressure between the non-dysphagic and dysphagic PD patients. These differences provide the characteristics of tongue movement during swallowing in PD patients with dysphagia, which may be useful for the diagnosis and treatment of dysphagia.

[Effects of tongue pressure sensor sheet on the signal waveform of laryngeal movement produced by bend sensor during deglutition].

OBJECTIVE: To evaluate the effects of the application of tongue pressure sensor sheet on the signal waveform of laryngeal movement produced by the bend sensor during deglutition. METHODS: Twelve adult male subjects were recruited to perform a single swallow of 5 ml water when sitting on the dental chair with upright position. The data recorded by bend sensor was obtained with attaching tongue pressure sensor sheet simultaneously or not. Then the measured parameters by bend sensor with or without concurrent application of tongue pressure sensor sheet were compared. RESULTS: There were no significant differences between the same time point on the signal waveform produced by bend sensor whether concurrently attaching tongue pressure sensor sheet or not (P > 0.05). Additionally, we found no statistical significances between matched phases on the signal waveform recorded by bend sensor with or without application of tongue pressure sensor sheet (P > 0.05). CONCLUSION: The findings in this study suggest us that the usage of tongue pressure sensor sheet exerted no influences on the waveform of the laryngeal movement produced by bend sensor during deglutition, facilitating us to further apply tongue pressure sensor sheet and bend sensor simultaneously to record tongue pressure production and hyoid activity during deglutition.

One step polymerizing technique for fabricating a hollow obturator.

PURPOSE: Although a closed hollow obturator is often applied to post maxillectomy patients, it has a few problems such as complexity of fabrication and water leakage to inside. A one step curing technique to fabricate a closed hollow obturator by constructing a small hollow bulb made by two thermoplastic resin sheets is described in the present report. METHODS: In the one step curing technique, after dewaxing the wax denture fabricated conventionally, one size smaller hollow body was fabricated with two thermoplastic resin sheets and set into the investment mold as a core. Then the circumferential part of obturator was cured by the pour type resin. This technique was used to fabricate an obturator prosthesis in a 60-year-old post-maxillectomy patient. The weight of this obturator was well controlled and the definitive prosthesis weighed 22 g. At a one year follow-up, the obturator fared well without any water leakage or breakage. CONCLUSIONS: This technique allows the fabricator to control the thickness and weight of the obturator by the amount of relief provided by the hollow bulb. It also rectifies the disadvantages of the closed hollow obturator such as water leakage and complexity of fabrication.

Relationship between tongue pressure and dysphagia in stroke patients.

BACKGROUND: Although poststroke dysphagia is an important issue for determining prognosis, the pathophysiology of oral-phase dysphagia has yet to be clarified due to a lack of adequate devices and protocols. The present study investigated the relationships between swallowing pressure production by the tongue and dysphagia in stroke patients using a newly developed method of tongue pressure measurement with a sensor sheet system. METHODS: Subjects were 64 stroke patients, including 30 patients with dysphagia. A T-shaped sensor sheet with 5 measuring points was attached to the hard palate to record tongue pressure while swallowing 5 ml of water. The average maximal magnitude and incidence of abnormalities such as asynchronous and/or polyphasic patterns in tongue pressure waves in 5 locations were compared between patients with and without dysphagia. RESULTS: The average maximal tongue pressure was significantly smaller in patients with dysphagia than in those without dysphagia. Asynchronous and polyphasic patterns showed a sensitivity of 63 and 87%, and a specificity of 91 and 71%, respectively, for identifying patients with dysphagia. CONCLUSION: Tongue pressure production during swallowing appears closely related to poststroke dysphagia. Tongue pressure measurement appears useful for evaluating the pathophysiology of oral-phase dysphagia in stroke patients.

Widening a narrow posterior mandibular alveolus following extirpation of a large cyst: a case treated with a titanium mesh-plate type distractor.

Vertical alveolar augmentation by distraction osteogenesis has become a standard pretreatment of dental implants due to the main benefit of lack of donor site complications, and many reports have shown its benefit with various types of alveolar distractors. However, autogenous bone transplantation and/or guided bone regeneration techniques are still the standard treatment for correcting a narrow alveolar ridge because of few commercially available distractors for alveolar widening. In this article, we treated a case by a mesh-plate type of alveolar widening distractor for a narrow posterior mandibular alveolar ridge after extirpation of a large jaw cyst.

Masticatory performance in postmaxillectomy patients with edentulous maxillae fitted with obturator prostheses.

PURPOSE: Oral cancer develops frequently in older populations. In Japan, the incidence of oral and pharyngeal cancer is 9,201 per year, with such tumors accounting for 1.74% of all cancers. Although obturator prostheses play an important role in the rehabilitation of postmaxillectomy patients, clinicians sometimes experience difficulty in placing obturator prostheses in edentulous maxillae, and criteria for the objective evaluation of treatment outcome have yet to be established. The present study aimed to investigate postsurgical factors influencing the masticatory performance of postmaxillectomy patients with edentulous maxillae fitted with obturator prostheses. MATERIALS AND METHODS: The extent of the hard palate defect, status of the mandibular dentition, mouth-opening distance, and maximum occlusal force were investigated, and masticatory performance was measured using a testing gummy jelly in 27 postmaxillectomy patients with edentulous maxillae fitted with obturator prostheses. The influence of these items was evaluated quantitatively, and theoretical masticatory performance for each subject was calculated using multiple-regression analysis (quantification method type 1). RESULTS: Although average masticatory performance was almost equivalent to that of healthy, independent older patients with occlusal support classified as Eichner C, considerable individual variation was noted among subjects. The order of strength of influence on masticatory performance was identified by category weight: extent of hard palate defect > status of posterior mandibular teeth > maximum occlusal force > mouth-opening distance. A relatively high correlation (R2 = 0.78, P < .01, Pearson correlation coefficient) was evident between theoretical and actual values. CONCLUSION: Masticatory performance could be predicted by evaluating postsurgical factors in patients with edentulous maxillae fitted with obturator prostheses.

Dysgerminoma in a patient with a tumor of the neck. Empiric treatment of stage IV dysgerminoma.

The evolution of therapy for malignant ovarian germ cell tumors is one of the true success stories in oncology. Treatment outcome has improved greatly thanks to cisplatin-based combination chemotherapy. According to the well-established treatment guidelines for advanced cases, we treated a case of stage IV undifferentiated germ cell tumor in which we were able to preserve the patient's fertility. We concluded that the PEP regimen is an effective treatment for the patient with metastatic germ cell tumor.