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Yoshiko Hara,1 Ayako Nakane,2 Haruka Tohara,2 Kazumasa Kubota,1 Kazuharu Nakagawa,2 Koji Hara,2 Kohei Yamaguchi,2 Kanako Yoshimi,2 Shunsuke Minakuchi1 1Department of Gerodontology and Oral Rehabilitation, Division of Gerontology and Gerodontology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan; 2Department of Dysphagia Rehabilitation, Division of Gerontology and Gerodontology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, JapanCorrespondence: Ayako NakaneDepartment of Dysphagia Rehabilitation, Division of Gerontology and Gerodontology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8549, JapanTel/Fax +81-3-5803-5562Email fujigerd@tmd.ac.jpPurpose: We aimed to determine the efficacy of interferential current transcutaneous electrical sensory stimulation (IFC-TESS) in patients with dementia who were being treated for dysphagia in nursing homes under normal living conditions.Patients and Methods: This study recruited 54 nursing home residents (13 males, 41 females; mean age, 84.5 ± 10.7 years) with dysphagia and dementia. IFC-TESS was performed with Gentle Stim® (Careido Co. Ltd., Kanagawa, Japan) for 15 minutes. Two sessions per day were administered 5 days per week, for 3 weeks. The outcomes included the improvement of the patients’ cough reflexes and nutritional states across the 3 weeks of intervention; the former was evaluated with the cough test based on the changes in cough latency time and cough frequency, while the latter was assessed based on changes in the functional oral intake scale (FOIS) score and oral calorie intake.Results: The cough latency times before and after the 3-week intervention were 15.8 (7.0– 60.0) and 6.7 (3.6– 30.7) s/min, respectively; the cough frequencies were 5.0 (0.0– 5.0) and 5.0 (5.0– 5.0) t/min, respectively; the FOIS scores were 5.0 (5.0– 6.0) and 5.0 (5.0– 6.0), respectively; and oral calorie intakes were 1300.0 (862.5– 1420.0) and 1300.0 (1005.0– 1462.5) kcal/day, respectively. All parameters significantly improved across the intervention (p < 0.05). When the results were adjusted for age, sex, body mass index, mini nutritional assessment results, Barthel index, and mini-mental state examination scores, IFC-TESS improved the cough reflex and oral calorie intake in older nursing home residents with dementia.Conclusion: Cervical IFC-TESS can improve the cough reflexes and nutritional states of patients with dysphagia and dementia in nursing homes. As it has previously been difficult to perform active rehabilitation with dementia patients, IFC-TESS may be effective and practicable for the rehabilitation of this patient population.Keywords: cough frequency, cough latency time, FOIS, IFC-TESS, oral calorie intake

Yuko Kagifuku,1 Haruka Tohara,1 Yoko Wakasugi,1 Chiaki Susa,1 Ayako Nakane,1 Mizue Toyoshima,2 Koichi Nakakuki,3 Yuji Kabasawa,4 Hiroyuki Harada,5 Shunsuke Minakuchi1 1Department of Gerontology and Gerodontology, Division of Gerodontology and Oral Rehabilitation, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan; 2Section of Nutrition Management, Tokyo Medical and Dental University Dental Hospital, Tokyo, Japan; 3Department of Maxillofacial Surgery, Division of Maxillofacial and Neck Reconstruction, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan; 4Department of Oral Care for Systemic Health Support, Graduate School of Health Care Sciences, Tokyo Medical and Dental University, Tokyo, Japan; 5Department of Oral and Maxillofacial Surgery, Oral Restitution, Division of Oral Health Sciences, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, JapanCorrespondence: Haruka ToharaDepartment of Gerontology and Gerodontology, Division of Gerodontology and Oral Rehabilitation, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8510, JapanTel/Fax +81-3-5803-5559Email haruka-t@rd5.so-net.ne.jpPurpose: There are few studies about sarcopenia before and after surgery for oral cancer. Therefore, we examined body composition during hospitalization and factors affecting weight loss, skeletal muscle mass index (SMI) reduction, and swallowing function at discharge in this patient group.Patients and Methods: A prospective survey was conducted at Tokyo Medical and Dental University Dental Hospital for patients who underwent primary surgery for oral cancer and reconstruction using free flaps. We compared body weight, SMI, grip strength, and walking speed at admission and discharge. We also examined factors affecting weight loss and SMI reduction and the functional oral intake scale (FOIS) score at discharge.Results: There were 26 patients that we could survey during the period. As a result of Wilcoxon’s signed-rank test, body weight, SMI, and grip strength were significantly reduced during hospitalization, but no reduction was noted for sarcopenia. As a result of multiple regression analysis, postoperative chemoradiotherapy was a risk factor for weight loss, reduced SMI, and low FOIS score at discharge.Conclusion: Postoperative chemoradiotherapy is a risk factor for weight loss, muscle mass loss, and dysphagia at discharge, and chemoradiotherapy may affect rather than an invasion of surgery. After surgery, besides follow-ups for cancer, oral cancer patients should be followed up to assess dysphagia, undernutrition, and sarcopenia.Keywords: sarcopenia, chemoradiotherapy, dysphagia, head and neck cancer

Chizuru Namiki,1 Koji Hara,1 Haruka Tohara,1 Kenichiro Kobayashi,2 Ariya Chantaramanee,1 Kazuharu Nakagawa,1 Takayuki Saitou,2 Kohei Yamaguchi,1 Kanako Yoshimi,1 Ayako Nakane,1 Shunsuke Minakuchi1 1Department of Gerodontology, Division of Gerontology and Gerodontology, Tokyo Medical and Dental University, Tokyo, Japan; 2Kobayashi Dental Clinic, Tokyo, Japan Purpose: Producing tongue pressure (TP) by pushing the tongue against the palate consists of lifting the tongue muscles and elevating the floor of the mouth via suprahyoid muscle contraction. Though studies have shown that tongue-pressure resistance training (TPRT) increases tongue function, none have focused on suprahyoid muscle function enhancements. Our study aimed to verify whether TPRT improves both tongue function and hyoid movement during swallowing.Materials and methods: Eighteen patients (mean age: 76.8±6.2 years) with presbyphagia presenting with symptoms such as coughing and choking were enrolled. All patients performed daily living activities independently. None of the participants had diseases causing dysphagia or previous oral or pharyngeal surgery. Participants were instructed to push their tongues against the palate as hard as possible with their mouths closed for 10 seconds, and then resting for 10 seconds. A set consisted of five consecutive exercise and resting periods; two sets per day were performed for a month. TP and the oral diadochokinetic rate (ODKR), measured by repetitions of the syllables /ta/ and /ka/, assessed tongue function. The extent of anterior and superior hyoid movement and parameters related to swallowing, including the penetration aspiration scale (PAS) and the normalized residue ratio scale (NRRS) in the valleculae (NRRSv) and piriform sinus (NRRSp), were evaluated based on videofluoroscopic data.Results: The anterior (P=0.031) and superior hyoid movement (P=0.012), TP (P=0.002), ODKR/ta/ (P=0.034), ODKR/ka/ (P=0.009), and the width of the upper esophageal sphincter (P=0.001) were larger at follow-up than at baseline. NRRSp (P=0.022), PAS (P=0.016), and pharyngeal transit times (P=0.004) were smaller at follow-up than at baseline.Conclusion: TPRT improved tongue strength, dexterity, both anterior and superior hyoid elevation, and swallowing functions. Therefore, TPRT could improve tongue function and suprahyoid muscle function simultaneously and contribute to prevention of sarcopenic dysphagia. Keywords: sarcopenic dysphagia, swallowing muscle, tongue function, suprahyoid muscle

Mariko Matsubara,1,2 Haruka Tohara,1 Koji Hara,1 Hiromichi Shinozaki,1 Yasuhiro Yamazaki,1 Chiaki Susa,1 Ayako Nakane,1 Yoko Wakasugi,1 Shunsuke Minakuchi1 1Gerodontology and Oral Rehabilitation, Department of Gerontology and Gerodontology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, 2Department of Oral Surgery, Ichigao Carillon Hospital, Kanagawa, Japan Purpose: This study was aimed to examine the effectiveness of a high-speed jaw-opening exercise, which targets the contraction of fast-twitch muscle fibers, in improving swallowing function.Subjects and methods: Twenty-one subjects (mean age 74.0±5.7 years) with dysphagia-related symptoms, such as coughing or choking during eating, performed the exercise. None of the included subjects had neurological symptoms or history of surgery that could cause significant dysphagia. All subjects took regular meals, and maintained independent activities of daily life. The exercise schedule consisted of 3 sets of 20 repetitions each of rapid and maximum jaw-opening movement with a 10-second interval between sets. The exercise was performed twice daily for 4 weeks.Results: Following the intervention, there was a significant increase in the vertical position of the hyoid bone at rest. Furthermore, during swallowing, the elevation of the hyoid bone and the velocity of its movement and esophageal sphincter opening increased significantly while the duration of the hyoid elevation and the pharyngeal transit time reduced significantly.Conclusions: Our results demonstrated that high-speed jaw-opening exercise resulted in increased elevation velocity of the hyoid bone during swallowing, indicating its role in effectively strengthening the fast-twitch muscle fibers of suprahyoid muscles. Furthermore, since the rest position of the hyoid bone appeared to have improved, this exercise may be especially useful in elderly individuals with a lower position of the hyoid bone at rest and those with decreased elevation of the hyoid bone during swallowing, which are known to be associated with an increased risk of aspiration. Keywords: deglutition disorders, jaw, exercise, rehabilitation, fast-twitch muscle fibers, high speed

Yasuhiro Yamazaki, Haruka Tohara, Koji Hara, Ayako Nakane, Yoko Wakasugi, Kohei Yamaguchi, Shunsuke Minakuchi Department of Gerodontology, Tokyo Medical and Dental University, Tokyo, Japan Purpose: This study aimed to determine whether excessive neck muscle tone affects hyoid bone kinetics during swallowing using videofluorography (VF) in an unnatural posture in healthy individuals. Subjects and methods: Subjects were 28 healthy adults (12 men, 16 women; mean age, 39.75±9.50 years) without any history or present complaints of swallowing disorders. We first established the participant’s posture a reclining wheelchair that was adjusted to a 30-degree angle with the headrest (without excessive neck muscle tone) or without headrest (with excessive neck muscle tone), used an electromyogram above the mylohyoid muscle to represent the suprahyoid muscles and above the sternohyoid muscle to represent the infrahyoid muscles to confirm neck muscle tone, and then conducted VF of swallowing measurements. Videofluorographic images were obtained when 5 mL of 50% (w/v) barium sulfate was being swallowed, and hyoid bone coordinate (the resting position and the elevated position), extent of horizontal and vertical hyoid bone elevation, as well as duration and velocity of hyoid bone elevation were evaluated (x-axis and y-axis coordinates for the resting position of hyoid bone are referred to as Xr and Yr, respectively; those for the elevated hyoid bone position induced during swallowing are referred to as Xs and Ys, respectively). Results: In the resting position of the hyoid bone, the Yr coordinates in those with excessive neck muscle tone were significantly lower than in those without excessive neck muscle tone. Vertical hyoid bone elevation and hyoid bone elevation velocity were significantly higher with excessive neck muscle tone than without excessive neck muscle tone, whereas horizontal elevation showed no significant differences. Conclusion: Our findings suggest that the generation of neck muscle tone due to inappropriate posture may encourage hyoid depression and increase the extent of hyoid bone elevation, thereby increasing the risk of aspiration. Keywords: dysphagia, swallow, muscle tone, hyoid bone, infrahyoid muscles, suprahyoid muscles

Hiromichi Shinozaki, Haruka Tohara, Mariko Matsubara, Nobuhiro Inokuchi, Yasuhiro Yamazaki, Ayako Nakane, Yoko Wakasugi, Shunsuke Minakuchi Department of Gerodontology, Tokyo Medical and Dental University, Tokyo, Japan Purpose: This study aimed to examine the relationship between jaw opening force and hyoid bone dynamics and resting position in elderly individuals based on gender. Subjects and methods: Subjects were 36 healthy elderly individuals aged ≥65 years without dysphagia (16 men and 20 women; mean age 75.5 years, range 65–88 years). Videofluorographic images during the swallowing of 10 mL of 40% (w/v) barium sulfate were obtained and the degrees of anterior, superior, and hypotenuse displacements of the hyoid bone and maximum/resting hyoid position were evaluated. Jaw opening force was measured three times using a jaw opening force sthenometer; the mean of these three measurements was used for analysis. Results: In men, there was a positive correlation between jaw opening force and resting hyoid position and negative correlations among all the degrees of anterior, superior, and hypotenuse displacements of the hyoid bone. In women, there was no statistically significant correlation between jaw opening force and any of the measurement items. There was no statistically significant correlation between jaw opening force and maximum hyoid position in either men or women. Conclusion: Our findings suggest that low jaw opening force leads to low resting hyoid position only in elderly men, and a lower hyoid position in healthy elderly men results in a larger total amount of hyoid displacement during swallowing. Moreover, a maximum hyoid position in healthy individuals of either gender does not differ depending on their jaw opening force. Keywords: aging, deglutition disorders, dysphasia, gender differences

Tomohito Sato,1 Shinya Minakuchi,1 Manabu Mochizuki,2 Masaru Takeuchi11Department of Ophthalmology, National Defense Medical College, Saitama, Japan; 2Department of Ophthalmology and Visual Science, Tokyo Medical and Dental University Graduate School of Medicine, Tokyo, JapanBackground: Tocilizumab is a humanized monoclonal anti-interleukin-6 (IL-6) receptor antibody and has been approved in Japan for the treatment of Castleman's disease, rheumatoid arthritis (RA), and systemic juvenile idiopathic arthritis. Conjunctivitis and dry eye are known ocular adverse effects, but uveitis has not been reported.Case report: A 72-year-old woman had undergone bilateral cataract surgery without complications. Six months after the surgery, she was diagnosed with RA and treated with tocilizumab infusion every 4 weeks. However, severe malaise and dizziness occurred after the third tocilizumab infusion, and the treatment was suspended. Since the symptoms associated with RA had resolved, she was followed without any medication thereafter. At 5 weeks after the third tocilizumab infusion, she developed severe anterior inflammation with hypopyon in her left eye, and her visual acuity dropped to less than 2/200. Considering her age and history of cataract surgery, endophthalmitis was suspected and a vitrectomy was performed, but no pathogens were detected from the intraocular fluid samples collected during surgery. The ocular inflammation was gradually resolved with systemic antibiotics and corticosteroids. However, severe anterior uveitis recurred in the same eye during the tapering of the systemic corticosteroids, when the aqueous humor IL-6 level was 46,100 pg/mL. The recurrent ocular inflammation was resolved with increased doses of topical and systemic corticosteroids, and the patient has since remained relapse-free. No symptom of inflammation was observed in the right eye during the follow-up period.Conclusion: This case indicates a possibility that acute anterior uveitis may have been an adverse effect after the discontinuation of anti-IL-6 receptor antibody therapy in a patient with RA.Keyword: interleukin-6

Yamazaki Y, Tohara H, Hara K, Nakane A, Wakasugi Y, Yamaguchi K, Minakuchi S. Clin Interv Aging. 2017;12: 1903–1910.Page 1903, the title, “Excessive anterior cervical muscle tone affects hyoid bone kinetics during swallowing in healthy individuals” should read “Excessive anterior cervical muscle tone affects hyoid bone kinetics during swallowing in adults”.Page 1903, Abstract, Purpose, line 3, “healthy individuals” should read “adults”.Page 1903, Abstract, Subjects and methods, “28 healthy adults (12 men, 16 women; mean age, 39.75±9.50 years) without any history or present complaints of swallowing disorders” should read “28 adults (12 men, 16 women; mean age, 39.75±9.50 years) who were suspected to have some symptom of swallowing disorders but did not have swallowing dysfunctional from the result of videofluorography”.Page 1904, right column, line 10, “healthy individuals” should read “adults”.Page 1904, Methods, Study participants, “The present study evaluated 28 healthy adults (12 men, 16 women; mean age, 39.75±9.50 years) without any history or present complaints of swallowing disorders” should read “The present study evaluated 28 adults (12 men, 16 women; mean age, 39.75±9.50 years) who were suspected to have some symptom of swallowing disorders but did not have swallowing dysfunctional from the result of videofluorography”.Read the original article

Purpose: The purpose of this study was to examine the effect of stress-breaking attachments at the connections between maxillary palateless overdentures and implants. Materials and Methods: Three-dimensional finite element models were used to reproduce an edentulous human maxilla with an implant-retained overdenture. Two-implant models (in the canine tooth positions on both sides) and four-implant models (in the canine and second premolar tooth positions on both sides) were examined. Stress-breaking material connecting the implants and denture was included around each abutment. Axial loads of 100 N were applied to the occlusal surface at the left first molar tooth positions. In each model, the influence of the stress-breaking attachments was compared by changing the elastic modulus from 1 to 3,000 MPa and the thickness of the stress-breaking material from 1 to 3 mm. Maximum stress at the implant-bone interface and stress at the cortical bone surface just under the loading point were calculated. Results: In all models, maximum stress at the implant-bone interface with implants located in the canine tooth position was generated at the peri-implant bone on the loading side. As the elastic modulus of the stress-breaking materials increased, the stress increased at the implant-bone interface and decreased at the cortical bone surface. Moreover, stress at the implant-bone interface with 3-mm-thick stress-breaking material was smaller than that with 1-mm-thick material. Conclusion: Within the limitations of this experiment, stress generated at the implant-bone interface could be controlled by altering the elastic modulus and thickness of the stress-breaking materials. [ABSTRACT FROM AUTHOR]

One of the difficulties in composite structural application is joining components. A T-joint is one of the important elements in aircraft structures. T-joints often fail at low load in the curved region of the L-shaped parts or the deltoid area because of its low throughthickness strength properties and cure-induced residual stress. Previous works mainly focused on properties of T-joints under mechanical loads, not considering the effect of residual deformation caused in the manufacturing process. In this current study, we applied the asymmetric lamination to the L-shaped parts to suppress spring-in deformation. We evaluated the effectiveness of the proposed design using a threedimensional shape measurement. It was revealed that spring-in deformation can be reduced without distortion in the planar parts using the asymmetric laminate design. In addition, the deltoid region is important from the view point of strength and its fracture often leads to the final failure of T-joints. In this current research, we proposed a new deltoid structure, which has looped fibers in the deltoid region, to improve the strength of T-joints. Tensile tests were conducted while measuring cross-sectional strain distribution using digital image correlation (DIC). We used asymmetric laminate design, fiber-looped deltoid, and hybrid structure that combined them. All types of the specimens showed improvement in initial failure load and maximum load compared to the conventional ones, confirming the effectiveness of the proposed design. [ABSTRACT FROM AUTHOR]

The interfacial interaction of veneering ceramic with zirconia is still not fully understood. This study aimed to characterize morphologically and chemically the zirconia-veneering ceramic interface. Three zirconia-veneering conditions were investigated: 1) zirconia-veneering ceramic fired on sandblasted zirconia, 2) zirconia-veneering ceramic on as-sintered zirconia, and 3) alumina-veneering ceramic (lower coefficient of thermal expansion [CTE]) on as-sintered zirconia. Polished cross-sectioned ceramic-veneered zirconia specimens were examined using field emission gun scanning electron microscopy (Feg-SEM). In addition, argon-ion thinned zirconia-veneering ceramic interface cross sections were examined using scanning transmission electron microscopy (STEM)-energy dispersive X-ray spectrometry (EDS) at high resolution. Finally, the zirconia-veneering ceramic interface was quantitatively analyzed for tetragonal-to-monoclinic phase transformation and residual stress using micro-Raman spectroscopy (µRaman). Feg-SEM revealed tight interfaces for all 3 veneering conditions. High-resolution transmission electron microscopy (HRTEM) disclosed an approximately 1.0-µm transformed zone at sandblasted zirconia, in which distinct zirconia grains were no longer observable. Straight grain boundaries and angular grain corners were detected up to the interface of zirconia- and alumina-veneering ceramic with as-sintered zirconia. EDS mapping disclosed within the zirconia-veneering ceramic a few nanometers thick calcium/aluminum-rich layer, touching the as-sintered zirconia base, with an equally thick silicon-rich/aluminum-poor layer on top. µRaman revealed t-ZrO2-to-m-ZrO2 phase transformation and residual compressive stress at the sandblasted zirconia surface. The difference in CTE between zirconia- and the alumina-veneering ceramic resulted in residual tensile stress within the zirconia immediately adjacent to its interface with the veneering ceramic. The rather minor chemical elemental shifts recorded in the veneering ceramic did not suffice to draw definitive conclusions regarding potential chemical interaction of the veneering ceramic with zirconia. Sandblasting damaged the zirconia surface and induced phase transformation that also resulted in residual compressive stress. Difference in CTE of zirconia versus that of the veneering ceramic resulted in an unfavorable residual tensile stress at the zirconia-veneering ceramic interface. [ABSTRACT FROM AUTHOR]

This study seeks to clarify the mechanism of strain development in curing a thick composite structure with a temperature distribution in the thickness direction. Strain developed during curing can be separated into two parts according to the causes. One is chemical cure shrinkage of the matrix; the other is thermal shrinkage (or expansion) of the cured composite. Therefore, this study consists of a cure-shrinkage part and a thermal-shrinkage part. In both parts, the curing was monitored with an embedded distributed optical-fiber sensor (pulse-pre-pump Brillouin optical-time-domain analysis, PPP-BOTDA) and analyzed. In the cure-shrinkage strain part, the strain distribution caused by different temperature histories was observed. We confirmed that the lower viscosity part was influenced by the cure shrinkage of the other part and that these phenomena can be analyzed by the visco-elastic cure model. In the thermal-strain part, the amount of total shrinkage strain and the apparent coefficient of temperature expansion distribution were observed in the thickness direction. Warpage of the specimen was also observed. These results were confirmed to be caused by the distribution of temperature and of the fiber volume fraction,Vf. [ABSTRACT FROM AUTHOR]

This study establishes an innovative composite cure monitoring technique by utilizing a newly developed hybrid Brillouin–Rayleigh optical fiber sensing system. The new system can separately measure strain and temperature distribution with only one optical fiber. This study began by evaluating the measurement accuracy of the hybrid system in a composite application in a step-by-step manner. A single optical fiber was then embedded in a carbon–epoxy specimen, and thermal residual strain development and temperature change were measured during the cooling period of the curing process. The temperature and residual strain obtained by the hybrid Brillouin–Rayleigh system agreed well with the results measured by a conventional sensor set (i.e. fiber Bragg grating sensors and thermocouples). Furthermore, the system could identify a nonuniform thermal residual strain field induced by a nonuniform cure temperature. These results clearly demonstrated that the proposed technique is quite useful for cure monitoring of large-scale composite structures. Quality assurance for whole parts of actual products can be effectively accomplished by applying the proposed technique. [ABSTRACT FROM PUBLISHER]