Stage Of Swallowing Research Articles

Autoimmune dysphagia.

Dysphagia is a complication of several autoimmune rheumatic diseases and otorhinolaryngologists are likely to be involved in the assessment and management of patients with such conditions. This review provides an update on rheumatic diseases that may cause swallowing impairment, with particular focus on the epidemiology, pathophysiology and management of dysphagia in these conditions. Dysphagia is a common complication of the following rheumatic diseases: idiopathic inflammatory myopathies, systemic sclerosis, Sjogren's syndrome, systemic lupus erythematosus and rheumatoid arthritis. It may also be a complication of rarer autoimmune conditions such as Bechet's syndrome, sarcoidosis and granulomatosis with polyangiitis. All three stages of swallowing (oral, pharyngeal and oesophageal) may be impaired in these conditions. Both medical therapy and surgical intervention play an important role in the management of autoimmune dysphagia. The investigation and management of autoimmune dysphagia requires close collaboration between rheumatologists and otorhinolaryngologists. There is a need for further research to establish standardised guidelines on the assessment and management of autoimmune dysphagia.

Evaluation of Swallowing Coordination in Infants with a History of Mechanical Ventilation Longer Than 7 Days in the Neonatal Period and Assessment of Response to Oral Stimulation Maneuver

Background: Dysphagia is a frequent complication defined as difficulty in any stage of swallowing. Infants with a history of mechanical ventilation might show difficulty in coordinating pharyngeal muscles resulting in dysphagia. Objectives: The present study aimed to show the prevalence of swallowing disorders and associated symptoms among high-risk infants with a history of prolonged mechanical ventilation. Methods: A quasi-experimental study was conducted at the Breastfeeding Research Center, Tehran, Iran. All the neonates with a history of prolonged mechanical ventilation entered the study. Parents were asked to respond to a provided questionnaire regarding their infants’ swallowing disorders. Accordingly, the infants with any symptoms were considered candidates for intervention. The parents also received simple training to perform oral sensorimotor stimulation protocol for their children. Through a follow-up visit, the questionnaire was filled up for every infant. Finally, all the data related to the responses before and after interventions were compared to show the possible effects of the interventions. Results: A total of 25 infants entered the study. The mean mechanical ventilation period was 15.95 ± 6.644 days. Concerning the frequency of swallowing complications, 24 infants (96%) had different degrees of dysphagia. After 3 - 6 months of interventions, the number of cases with symptoms of coughing (P = 0.016), spitting food out by mouth (P = 0.0001), choking (P = 0.016), humid breath (P = 0.031), poor weight gain (P = 0.002), and the need to cut food into small pieces (P = 0.004) was significantly lower than the number of cases suffering from such complications before the intervention. The results also showed that after 3 - 6 months of interventions, dysphagia symptoms in 10 out of 24 infants (41.66%) entirely and in others (38.44%) partially improved. Conclusions: The results of the present study delineated that infants with a history of prolonged mechanical ventilation were at greater risk of swallowing complications. The early diagnosis and implementation of oral sensorimotor interventions could improve different symptoms of dysphagia.

Automated assessment of hyoid movement during normal swallow using ultrasound.

BackgroundThe potential for using ultrasound by speech and language therapists (SLTs) as an adjunct clinical tool to assess swallowing function has received increased attention during the COVID‐19 pandemic, with a recent review highlighting the need for further research on normative data, objective measurement, elicitation protocol and training. The dynamic movement of the hyoid, visible in ultrasound, is crucial in facilitating bolus transition and protection of the airway during a swallow and has shown promise as a biomarker of swallowing function.AimsTo examine the kinematics of the hyoid during a swallow using ultrasound imaging and to relate the patterns to the different stages of a normal swallow. To evaluate the accuracy and robustness of two different automatic hyoid tracking methods relative to manual hyoid position estimation.Methods & ProceduresUltrasound data recorded from 15 healthy participants swallowing a 10 ml water bolus delivered by cup or spoon were analysed. The movement of the hyoid was tracked using manually marked frame‐to‐frame positions, automated hyoid shadow tracking and deep neural net (DNN) tracking. Hyoid displacement along the horizontal image axis (HxD) was charted throughout a swallow, and the maximum horizontal displacement (HxD max) and maximum hyoid velocity (HxV max) along the same axis were automatically calculated.Outcomes & ResultsThe HxD and HxV of 10 ml swallows are similar to values reported in the literature. The trajectory of the hyoid movement and its location at significant swallow event time points showed increased hyoid displacement towards the peak of the swallow. Using an interclass correlation coefficient, HxD max and HxV max values derived from the DNN tracker and shadow tracker are shown to be in high agreement and moderate agreement, respectively, when compared with values derived from manual tracking.Conclusions & ImplicationsThe similarity of the hyoid tracking results using ultrasound to previous reports based on different instrumental tools supports the possibility of using hyoid movement as a measure of swallowing function in ultrasound. The use of machine learning to automatically track the hyoid movement potentially provides a reliable and efficient way to quantify swallowing function. These findings contribute towards improving the clinical utility of ultrasound as a swallowing assessment tool. Further research on both normative and clinical populations is needed to validate hyoid movement metrics as a means of differentiating normal and abnormal swallows and to verify the reliability of automatic tracking.WHAT THIS PAPER ADDSWhat is already known on this subject There is growing interest in the use of ultrasound as an adjunct tool for assessing swallowing function. However, there is currently insufficient knowledge about the patterning and timing of lingual and hyoid movement in a typical swallow. We know that movement of the hyoid plays an essential role in bolus transition and airway protection. However, manual tracking of hyoid movement is time‐consuming and restricts the extent of large‐scale normative studies. What this study adds We show that hyoid movement can be tracked automatically, providing measurable continuous positional data. Measurements derived from this objective data are comparable with similar measures previously reported using videofluoroscopy and of the two automatic trackers assessed, the DNN approach demonstrates better robustness and higher agreement with manually derived measures. Using this kinematic data, hyoid movement can be related to different stages of swallowing. Clinical implications of this study This study contributes towards our understanding of the kinematics of a typical swallow by evaluating an automated hyoid tracking method, paving the way for future studies of typical and disordered swallow. The challenges of image acquisition highlight issues to be considered when establishing clinical protocols. The application of machine learning enhances the utility of ultrasound swallowing assessment by reducing the labour required and permitting a wider range of hyoid measurements. Further research in normative and clinical populations is facilitated by automatic data extraction allowing the validity of prospective hyoid measures in differentiating different types of swallows to be rigorously assessed.

Effect of the rheological properties of the liquid carrier on the in vitro swallowing of solid oral dosage forms

Solid oral dosage forms (SODF) are the most popular oral drug delivery forms, but they can be difficult to swallow, especially for patients suffering from swallowing disorders. This study investigated the dynamics of different combinations of liquid carriers and SODF during the oral phase of swallowing using an in vitro model. The rheological properties of the carriers were characterized using shear and extensional rheometry, and their effect on bolus velocity, bolus shape, post-swallow residues, and SODF position within the bolus was evaluated. The latter has been identified as a novel and promising variable to discriminate between alternative formulations. When swallowed with water, capsules and tablets did not impact significantly the velocity of the bolus, but they lagged behind the liquid bolus, suggesting that low viscosity Newtonian fluids are not efficient carriers for SODF. Increasing the viscosity of the carrier at high shear rates improved the ability of the liquid to transport the SODF but also increased the amount of post-swallow residues. At equivalent shear viscosity, elastic and extensional properties of carriers influenced positively the position of the SODF in the bolus. Capsules and tablets were transported toward the front of these boluses, during the oral phase of swallowing, which is considered beneficial to avoid SODF sticking to the mucosa in the following stages of swallowing. Thin elastic liquids appear as an interesting option to promote safe swallowing of capsules and tablets. Clinical studies are, however, necessary to confirm this positive effect in healthy and dysphagic patients.

Is there a role of functional endoscopic evaluation of swallowing (FEES) in aiding tracheotomy decannulation post oral cancer surgery?

e18523 Background: A significant proportion of patients with oral cancer require perioperative tracheotomy. The altered oral anatomy post surgery significantly impairs the first and second stages of swallowing, resulting in swallowing dysfunction and potential aspiration. There is no priordata on utilization of FEES or other objective tools to predict successful tracheotomy decannulation in patients with oral cancer. Methods: This constituted a retrospective analysis of 237 patients with oral cancer treated at our institution between Feb 2017 and Dec 2019. Seventy two (30.4%)patients underwent perioperative tracheotomy. Post surgery,after excluding patients who were not considered candidates for early decannulation, 48 (65.7%) underwent FEES with the endpoint of tracheotomy decannulation. The number of FEES procedures required for decannulation was correlated with patient and disease-specific variables utilizing Chi square analysis. Results: The rate of successful decannulation was 100%. The mean number of days from tracheotomy to decannulation was 24.9. Thirty two (66.7%) patients underwent decannulation post the first FEES, notablyupon documentation of no penetration or aspiration to three bolus consistencies. However, 33.3% patients needed swallowing therapy followed by a second (18.8%) or a third (14.6%) FEES before they could be decannulated (late decannulation). No patients required a repeat tracheotomy. A significantly higher proportion of individuals at or younger than median age were decannulated earlier, compared with individuals above median age ( p= 0.01). There was no statistically significant difference between early (T1/2) and advanced (T3/4) primary lesions and timing of decannulation ( p= 0.83). The presence of comorbid diabetes mellitus did not correlate with decannulation timing ( p= 0.81). Conclusions: FEES constitutes a reliable, minimally invasive and cost-effective tool to aid successful decannulation across all stages of oral cancer. It may be indicated especially in older individuals. It helps guide swallowing therapy, and thus potentially augments quality of life by tailoring serial evaluations to aid early decannulation.

Mice Lacking Brain-Derived Serotonin Have Altered Swallowing Function.

The intricate sensorimotor neural circuits that control swallowing are heavily reliant on serotonin (5-hydroxytryptamine [5-HT]); however, the impact of 5-HT deficiency on swallow function remains largely unexplored. We investigated this using mice deficient in tryptophan-hydroxylase-2 (TPH2), the enzyme catalyzing the rate-limiting step in 5-HT synthesis. Videofluoroscopy was utilized to characterize the swallowing function of TPH2 knockout (TPH2-/-) mice as compared with littermate controls (TPH2+/+). Results showed that 5-HT deficiency altered all 3 stages of swallowing. As compared with controls, TPH2-/- mice had significantly slower lick and swallow rates and faster esophageal transit times. Future studies with this model are necessary to determine if 5-HT replacement may rescue abnormal swallowing function. If so, supplemental 5-HT therapy may have vast applications for a large population of patients with a variety of neurologic disorders resulting in life-diminishing dysphagia, particularly amyotrophic lateral sclerosis and Parkinson's disease, for which 5-HT deficiency is implicated in the disease pathogenesis.

New application of dynamic magnetic resonance imaging for the assessment of deglutitive tongue movement

BackgroundDeglutitive motion of the tongue may function to maintain tooth position. However, the causation between abnormal patterns of orofacial muscle function and dental malocclusion remains unclear. To clarify the pathogenic mechanism of malocclusion, it is important to determine the relative positional relationship between the tongue tip and incisor edge or the dorsal tongue and palate during deglutition. Here, we assessed the utility of 3-T segmented cine-magnetic resonance (MR) imaging, combined with static MR images for hard tissue visualization, in assessing the relationship between the tongue and the surrounding tissues during deglutitive tongue movement.MethodsCine-MR images were acquired from three healthy female volunteers during deglutition who had no history of swallowing disorder or other chronic illness, normal alignment and occlusion, and a skeletal class I relationship. Three cine-MR images were taken during deglutition in accordance with an auditory cue for each volunteer. During static imaging, custom-made, contrast-medium-filled clear retainers were positioned in the mouth to allow visualization of the upper and lower incisors and hard palate boundaries. Static images were superimposed onto images of the three stages in deglutitive tongue movement, which were selected from a series of cine-MR images. These superimpositions were assessed five times by tracing cephalometric parameters to examine the reproducibility of the method.ResultsTraces varied little across repeated measurements, and all subjects had a similar pattern of dorsal tongue movement. Tongue-to-palate contact increased slightly during the first to second stage of swallowing and abruptly increased during the second to third stage, while the tongue tip position remained constant.ConclusionsSegmented cine-MR imaging combined with static MR images is useful for assessing soft tissue motion during deglutition. This method is particularly useful in dentistry to evaluate the relationship between tongue function and maxillofacial morphology in terms of orthodontic treatment and orofacial myofunctional therapy, and for improving tongue movement during speech therapy.

The value of oropharyngoesophageal scintigraphy in the management of aspiration into the tracheobronchial tree in neurological patients

AimDysphagia and bolus aspiration are two of the most frequent and invalidating symptoms of various neurological diseases. Swallowing disorders often lead to tracheobronchial aspiration with consequent pneumonia episodes. Aspiration pneumonia per se constitutes the most frequent cause of death in these patients, with mortality rate ranging from 20% to 62%. Oropharyngoesophageal scintigraphy (OPES) permits functional quantitative assessment of the different stages of swallowing, together with the detection and quantitative measurement of bolus aspiration. In this work, we analyzed the role of OPES in patients with different neurological conditions to evaluate swallowing and to detect and quantify bolus aspiration. Material and methodsWe enrolled 43 neurological patients (25 women and 18 men, mean age 67.3±12.4 yr) complaining of dysphagia with suspected inhalation. All patients underwent OPES with 99mTc-nanocolloid using a liquid bolus first, followed by a semi-solid bolus. We evaluated the following parameters: Oral, Pharyngeal and Esophageal Transit Time, Oro-Pharyngeal Retention Index, Esophageal Emptying Rate, and Aspiration Rate (% AR). ResultsOPES detected some airway aspiration in 26/43 patients. 19 patients had tracheal aspiration (with a mean 18.1% AR) and the remaining 7 patients had bilateral broncho-pulmonary aspiration (mean 44.9% AR). ConclusionsOPES is a feasible, repeatable and noninvasive method that allows quantitative assessment of bolus aspiration into the tracheobronchial tract, thus representing a useful and accurate tool to guide the most appropriate treatment and to monitor response to therapy in neurological patients with dysphagia.

Role of Occupational Therapy in Dysphagia Management for Children with Special Needs

Eating is the most basic ADL (Activities for Daily Living) necessary for survival from birth until death. Dysphagia is a swallowing disorder that can occur in any stage of swallowing. Occupational therapists are trained to assess and provide intervention in the process of eating. Occupational Therapy (OT) in Dysphagia Management includes assessment which provides performance issues involved in the task of eating (sensory motor, cognitive, behavioural, psycho-social etc) needed for the activity. This helps in the intervention, suggestion of an adaptation, modification or assistive technology device for a client as per the need.

Relationship between Class III malocclusion and hyoid bone displacement during swallowing: a cine-magnetic resonance imaging study

ObjectiveThe displacement of the hyoid bone (HB) is a critical biomechanical component of the swallowing function. The aim of this study was to evaluate the swallowing-induced vertical and horizontal displacements of the HB in subjects with 2 different magnitudes of skeletal Class III malocclusion, by means of real-time, balanced turbo-field-echo (B-TFE) cine-magnetic resonance imaging.MethodsThe study population comprised 19 patients with mild skeletal Class III malocclusion, 16 with severe skeletal Class III malocclusion, and 20 with a skeletal Class I relationship. Before the commencement of the study, all subjects underwent cephalometric analysis to identify the nature of skeletal malformations. B-TFE images were obtained for the 4 consecutive stages of deglutition as each patient swallowed 10 mL of water, and the vertical and horizontal displacements of the HB were measured at each stage.ResultsAt all stages of swallowing, the vertical position of the HB in the severe Class III malocclusion group was significantly lower than those in the mild Class III and Class I malocclusion groups. Similarly, the horizontal displacement of the HB was found to be significantly associated with the severity of malocclusion, i.e., the degree of Class III malocclusion, while the amount of anterior displacement of the HB decreased with an increase in the severity of the Class III deformity.ConclusionsOur findings indicate the existence of a relationship between the magnitude of Class III malocclusion and HB displacement during swallowing.

VFS Interjudge Reliability Using a Free and Directed Search

Reports in the literature suggest that clinicians demonstrate poor reliability in rating videofluoroscopic swallow (VFS) variables. Contemporary perception theories suggest that the methods used in VFS reliability studies constrain subjects to make judgments in an abnormal way. The purpose of this study was to determine whether a directed search or a free search approach to rating swallow studies results in better interjudge reliability. Ten speech pathologists served as judges. Five clinical judges were assigned to the directed search group (use checklist) and five to the free search group (unguided observations). Clinical judges interpreted 20 VFS examinations of swallowing. Interjudge reliability of ratings of dysphagia severity, affected stage of swallow, dysphagia symptoms, and attributes identified by clinical judges using a directed search was compared with that using a free search approach. Interjudge reliability for rating the presence of aspiration and penetration was significantly better using a free search ("substantial" to "almost perfect" agreement) compared to a directed search ("moderate" agreement). Reliability of dysphagia severity ratings ranged from "moderate" to "almost perfect" agreement for both methods of search. Reliability for reporting all other symptoms and attributes of dysphagia was variable and was not significantly different between the groups.

An unusual case of dysphagia following routine electrical DC cardioversion.

Dysphagia can arise from a multitude of underlying pathologies affecting any of the three stages of swallowing; oral, pharyngeal and or oesophageal; and can be further classified as intraluminal, intramural or extramural. We discuss an unusual case of acute dysphagia secondary to haematoma formation within one of a number of potential neck spaces. We report on a novel precipitant; routine electrical cardioversion. A review of relevant anatomical boundaries, symptoms, precipitants and treatment options will be discussed.

Analysis of Swallowing Function Using DIPP‐Motion Pro 2D®

DIPP-Motion Pro 2D® software is a new computerized system for quantitative analysis of motion of an object on screen automatically. It has been reported that cineradiography has been performed to analyze hyoid and laryngeal movements during swallowing; however, due to cost and preparation time, this method has not yet reached the clinical application stage. To overcome these problems, we have devised a new computerized system for quantitative analysis of video fluorography images using commercial “DIPP-Motion Pro 2D” software. DIPP-Motion Pro 2D® enables the efficient analysis including motion image sequence analysis, automatic tracking, measurement of distance and velocity, and graph display. With this system, quantitative studies were performed to analyze swallowing movements in 6 subjects without dysphagia. The median hyoid bone movement is 1.03cm(X-axis),1.59cm(Y-axis). The median laryngeal movement is 0.91cm(X-axis),2.46cm(Yaxis).The maximum bolus speed is 99.15cm/sec. We can analyze swallowing function conveniently and effectively with this system. It also could display the data with visual information. Therefore, it may become a tool to analyze swallowing function quantitatively in clinical practice. It also allows us to effectively exchange information with other medical personnel and gain informed consent. We can analyze swallowing function conveniently and effectively with this system, and it displays the data with visual information. Therefore, it may become a tool to analyze swallowing function quantitatively in clinical practice. Furthermore, it helps us to effectively exchange information with other medical personnel and gain informed consent. Cineradiography has made it possible to perform detailed visual analysis of the second stage of swallowing (hyoid and laryngeal movements) . Due to cost and preparation time, this method has not yet reached the clinical application stage. To overcome these problems, we have devised a new computerized system for quantitative analysis of video fluorography images using commercial “DIPP-Motion Pro 2D® software.

Flow properties of oral contrast medium formulations depend on the temperature

During the therapeutic videofluoroscopic examination of swallowing, gradation of bolus volume, texture, and viscosity can be implemented to determine the optimal bolus characteristics in that particular patient. When a thickened liquid is given to a dysphagic patient it is served at room temperature. However, in these patients with a delayed oral and/or pharyngeal stage of swallow, the bolus is held for a long time in the oral cavity. The temperature of the thickened liquid thereby increases. To study the rheological exploration (variation of viscosity with temperature) of thickened food used for radiologic swallowing examinations in patients with oral and pharyngeal dysfunction, in particular in mixtures of barium sulfate suspensions and in iodine solutions. Deep-frozen mango purée was thawed at room temperature. It was then mixed with barium sulfate contrast medium to a density of 25% w/w. Resorce Thicken Up was mixed at room temperature at two concentrations: 4.3% w/w (4.5 g thickener + 100 g distilled water) and 6.0% w/w (4.5 g thickener + 70 g distilled water). The thickener consisted of modified corn starch. Resorce Thicken Up was also mixed at room temperature with two concentrations of an iodine contrast material, iohexol (Omnipaque, 350 mg I/ml). The two concentrations were: 4.3% w/w (4.5 g thickener + 100 g iohexol) and 6% w/w (6 g thickener + 100 g iohexol). Measurements were carried out from 20 degrees C to 37 degrees C using a Stresstech HR rheometer. The rheometer was equipped with a concentric cylinder measuring system (inner cylinder 15 mm). The samples containing thickener in water as well as in iohexol showed a dependence on thickener concentration and temperature. The mango purée with barium sulfate displayed very small temperature dependence. The thickener solutions in iohexol had significantly higher viscosity compared with the other thickener solutions and the mango purée. The relative decrease shows that mango purée, the 6% thickener solution in water, and solutions with iohexol exhibited similar relative viscosity change at different temperatures. Our conclusion is therefore that it is important always to make the solution with high precision. It is also of importance to observe how long the patient keeps the bolus in the mouth. This might vary and actually it may not be possible to influence this factor. When different types of thickeners are compared, it is important to take into account the temperature at which the thickener is observed.

Assessment of Swallowing by Oropharyngoesophageal Scintigraphy in Patients with Amyotrophic Lateral Sclerosis

Amyotrophic lateral sclerosis (ALS) is the most common degenerative motor neuron disease in adults, and dysphagia is one of its most frequent and disabling symptoms. Oropharyngoesophageal scintigraphy (OPES) permits a functional and semiquantitative study of the various stages of swallowing. We studied 28 ALS patients (12 females and 16 males; mean age = 63.57 +/- 10.39 yr SD), who were clinically rated against the ALSFRS scale (Amyotrophic Lateral Sclerosis Functioning Rating Scale) and underwent OPES with (99m)Tc-nanocolloid using either a liquid or a semisolid bolus. The semiquantitative parameters we analyzed were Oral Transit Time (OTT), Pharyngeal Transit Time (PTT), Esophageal Transit Time (ETT), Retention Index (RI), and Esophageal Emptying Rate (EER(10s)). Hence, the OPES performed with a semisolid bolus produced a higher proportion of pathologic values for the swallowing variables than when liquid bolus was used. Analyzed by grouping the patients into classes according to their bulbar ALSFRS scores, we found a significant increase in the OTT (p < 0.005), PTT (p < 0.02), and Oropharyngeal Retention Index (OPRI) (p < 0.0004) variables in ALS patients with more severe bulbar involvement. OPES has turned out to be a very important examination for detecting tracheal-bronchial inhalation and it also offers the possibility of acquiring a semiquantitative evaluation of the amount of food inhaled. In our experience, OPES in patients with ALS has been easy to use, economic, well tolerated, and capable of supplying precise indications with regard to the extent of the swallowing disorder, which permits a better clinical definition of the ALS patient.

Handy measurement for tongue motion and coordination with laryngeal elevation at swallowing.

At the oral stage of swallowing, the tongue plays a major role and proper tongue performance is necessary to form the bolus and transfer it to the pharynx. For the present study we built a prototype device for safe and handy objective estimation of tongue motion and coordination with laryngeal elevation at swallowing. The device records tongue pressure by means of two strain gauge pressure transducers aligned 20 mm apart on a brass strap placed along the palatal midline. Laryngeal vibration is recorded with piezo-electric acceleration transducers. Time differences between pressure onset at the anterior and posterior transducers and the first spike from laryngeal vibration are measured. Ten healthy subjects were asked five times to swallow 5 mL of water. Pressure onset at the anterior transducer preceded posterior pressure by 294 +/- 164 ms. Given the distance between the transducers, the tongue contracted (squeezed) at a speed of 93 +/- 60 mm s(-1). Laryngeal vibration occurred 671 +/- 175 ms after the onset of anterior pressure. There was considerable variation in these parameters between subjects. Though the data is limited, the device successfully and easily revealed certain aspects of tongue motion and coordination with laryngeal elevation.

Considerations in Evaluating and Treating the Oral Stage of Swallowing

Considerations in Evaluating and Treating the Oral Stage of Swallowing

The management of drooling problems in children with neurological dysfunction: a review and case report

Drooling in children with neurological dysfunction indicates neurogenic failure to coordinate the muscles of the tongue, soft palate, and face which act in the first stage of swallowing. This causes excessive pooling of saliva in the anterior part of the mouth and consequent overspill. Treatment for drooling includes behavioral, pharmacological, and surgical modalities. Correcting a malocclusion has also been reported to help eliminate drooling. This paper describes the treatment of a child with neurofibromatosis, psychomotor, developmental, and neurologic retardation, and difficulty with speech. The patient was referred to our clinic to correct his drooling. Simple orthodontic treatment succeeded in eliminating the drooling and improving his speech.

上下顎同時印象による総義歯の臨床

Swallowing is the most important movement in the oral cavity as an inret of nutrition essential to the maintenance of the human life. At that time, patients wearing full dentures due to edentulous jaw have comparable movements to those observed in the dentulous jaw. Namely, the tongue press its tip against the rugae of palate in the first stage of swallowing, and then gradually establishes contact between its back and the posterior portion of palate with pressure to transport the food into the pharynx. During this couse, the contact of the posterior portion of tongue with dentures plays an important role in stabilization of dentures.Strack has proposed that arrangement of artificial teeth in the same place as that of the natural dentition is the best way to maintain the stability of denture.In recent years, techniques of making dentures have been improved with the advancement of dental materials. I devised a method of simultaneously making impressions of upper and lower jaws using a injection device and a silicon impression material. I have routinely used this new system to make full dentures for clinical cases.On this occasion, registration of interocclusal relation, gothic arch tracing, simultaneoustaking of upper and lower impressions, and face bow transfer will be performed in front of you using patients, from the initial examination to the setting of full dentures.

Physiology of oropharyngeal swallow in the cat: a videofluoroscopic and electromyographic study.

The majority of animal studies of deglutition have examined electrically stimulated swallows in sedated animals. This present investigation examined oropharyngeal and cervical esophageal swallow physiology in three awake normal domestic cats using concurrent electromyography (EMG) and videofluorography (VFG). Hooked wire electrodes were surgically implanted into six oropharyngeal muscles in each cat. During collection of VFG and EMG data, each cat ate barium-impregnated cat food while the fluorography tube focused on a lateral view of the oral cavity, pharynx, and cervical esophagus. A number of significant differences in the physiology of swallowing were found between the cat and human adult. The oral stage of swallow is much longer in the cat with bolus accumulation in the valleculae. Duration and components of the pharyngeal stage of swallow are much faster, and the pharyngeal stage occurs earlier in relation to bolus passage through the cricopharyngeus. In addition, the cat exhibits a marked superior constrictor bulge at the onset of the pharyngeal contractile wave and summation of the peristaltic waves in the esophagus, whereas the human adult does not. Feline swallow physiology is more similar to that of the human infant than that of human adults.