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Dive into the research topics where Hidemi Yoshimasu is active.

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Featured researches published by Hidemi Yoshimasu.


International Journal of Clinical Oncology | 2001

Clinicopathological study of carcinomas of the lip and the mucosa of the upper and lower lips

Ichiro Ogura; Teruo Amagasa; Hiroshi Iwaki; Takeshi Kijima; Tohru Kurabayashi; Hidemi Yoshimasu

AbstractBackground. Lip carcinomas are rare oral tumors, and there have been few reports of lip carcinoma in Japan. Methods. Of 914 patients with oral carcinomas treated between January 1980 and December 1998, 12 (1.3%) had lip carcinoma and 5 (0.5%) had lip mucosal carcinoma. We investigated the clinicopathological features of these 17 patients. Results. Of the 12 patients with carcinoma of the lip, 10 had squamous cell carcinomas (9, external lower lip; 1 commissures) and 2 had mucoepidermoid carcinomas (external upper lip). Of the 5 patients with lip mucosal carcinoma, 3 had squamous cell carcinomas (2, mucosa of the lower lip; 1, mucosa of the upper lip), 1 had mucoepidermoid carcinoma (mucosa of the lower lip), and 1 had acinic cell carcinoma (mucosa of the lower lip). Of the 12 patients with lip carcinoma, 9 were classified as stage I, 2 as stage II, and 1 as stage III; all 5 of the patients with lip mucosal carcinoma were stage I. Five patients with lip carcinoma were treated by resection, 5 by a combination of resection and reconstruction, and 2 by radiotherapy alone. All patients with lip mucosal carcinoma were treated by resection. After the initial therapy, 3 patients without neck dissection had regional recurrences and received delayed neck dissection, and 2 died with neck regional recurrence after dissection. The 5-year cumulative survival rates of the patients with lip carcinoma and those with lip mucosal carcinoma were 82.5% and 80.0%, respectively. Conclusion. We suggest that early-stage carcinomas of the lip and of the mucosa of the upper and lower lips are frequent, and we found that the outcome of these patients was excellent. However, an aggressive therapeutic approach to the lip carcinoma patient with cervical metastasis appears warranted, in an attempt to improve locoregional control and ultimate survival.


Journal of Cranio-maxillofacial Surgery | 1998

Quantitative evaluation of consistency of normal mucosa, leukoplakia and squamous cell carcinoma of the tongue

Ichiro Ogura; Teruo Amagasa; Eiji Fujii; Hidemi Yoshimasu

The quantitative differences in consistency of normal mucosa, leukoplakia and squamous cell carcinoma of the tongue were studied. Forty-five patients with squamous cell carcinoma of the tongue, 26 with leukoplakia and 80 with normal tongues were examined using an instrument capable of measuring consistency as a function of the load (in grams) needed to displace tongue mucosa by 2.0 mm using a probe 2.0 mm in diameter. The mean value for consistency in tongue carcinoma, leukoplakia and normal tongue was 22.1 +/- 8.0 g, 8.3 +/- 2.0 g and 4.8 +/- 0.7 g, respectively. Differences in consistency among these entities were significant (P < 0.001). Furthermore, consistency in tongue carcinoma was significantly correlated to tumour thickness (r = 0.954, P < 0.001). It was concluded that the consistency in tongue lesions was objectively and quantitatively evaluated by this method, and this technique could measure the thickness of the tumorous lesions preoperatively.


Biomaterials | 1994

Basic properties of superelastic Ni-Ti alloy ligature wires for a new intermaxillary fixation method

Takayuki Yoneyama; Hisashi Doi; Hitoshi Hamanaka; Kenichi Tomitsuka; Hidemi Yoshimasu; Nobuyuki Tanaka; Teruo Amagasa

A new continuous wiring method of intermaxillary fixation with super-elastic Ni-Ti alloy ligature wires was developed to avoid the risk in postoperative emergency. Differential scanning calorimetry, three-point bending tests and fastening tests were carried out to investigate basic properties of the wires. Transformation temperatures of the Ni-Ti alloy wires were in the range suitable for exhibiting super-elasticity at body temperature. The Ni-Ti alloy wires possessed enough bending flexibility to be used in the continuous wiring method and showed great recoverable displacement in the fastening test. With use of these properties, easy removal in an emergency and uniform fixation can be attained.


International Journal of Clinical Oncology | 1999

Quantitative evaluation of consistency of early invasive carcinoma of the tongue

Ichiro Ogura; Teruo Amagasa; Takeshi Miyakura; Eiji Fujii; Masashi Sato; Hidemi Yoshimasu

AbstractBackground. This study quantitatively evaluated the consistency of early invasive carcinoma of the tongue to enable the early detection of tongue cancer. Methods. The study population comprised 18 patients with early invasive squamous cell carcinoma of the tongue, 8 with lichen planus, 27 with leukoplakia, and 56 with advanced squamous cell carcinoma. All patients were examined with an instrument that measured consistency as a function of the load (in grams) needed to displace tongue mucosa by 2.0 mm, with a probe 2.0 mm in diameter. The consistency of early invasive carcinoma was compared with the consistency of normal mucosa and the consistency of the other tongue disease lesions. Consistency was also analyzed in relation to lesion size (diameter), clinical type, and histologic characteristics (grade of keratinization in the surface keratinized layer, degree of lymphoplasmacytic infiltration, and tumor thickness). Results. The mean values for the consistency of early invasive carcinoma, normal mucosa, lichen planus, leukoplakia, and advanced carcinoma lesions were 11.6 ± 2.3, 4.9 ± 0.7, 5.1 ± 0.4, 8.3 ± 2.0, and 25.4 ± 8.5 g, respectively. Early invasive carcinoma was firmer than normal mucosa (P < 0.001), lichen planus (P = 0.017), and leukoplakia (P = 0.087). Advanced carcinoma was firmer than early invasive carcinoma (P < 0.001). In early invasive carcinoma, tumors more than 1-mm-thick were significantly firmer than those less than 1-mm-thick (P = 0.013). Conclusions. This study demonstrated differences in consistency between early invasive carcinoma of the tongue and the lesions of other tongue diseases. Preoperative quantification of tumor consistency by this method could be helpful for the clinical diagnosis of early carcinoma of the tongue.


Healthcare | 2018

A Comparative Study of Oral Health Status between International and Japanese University Student Patients in Japan

Ai Ohsato; Masanobu Abe; Kazumi Ohkubo; Hidemi Yoshimasu; Liang Zong; Kazuto Hoshi; Tsuyoshi Takato; Shintaro Yanagimoto; Kazuhiko Yamamoto

Background: The number of international students enrolled in universities in Japan is increasing. To provide better oral care services for international students, we have to understand their oral environment and dental health behaviors. However, few studies have investigated the oral health status of international university students. The object of the present study was to clarify the current oral status of international university students. Methods: The subjects were students who visited the dental department at the University of Tokyo’s Health Services Center between April 2012 and March 2013. Our medical records were reviewed with regard to the following items: attributes (nationality, gender, and age); chief complaint (reason for visit); history of dental treatment; mean number of decayed (D), missing (M) or filled (F) teeth as a single (DMFT) index; degree of calculus deposition; gingival condition; and oral hygiene status. Results: The records of 554 university students (138 international and 416 non-international students) were analyzed; 88.4% of the 138 international students were from Asian countries (n = 122), of which 47.1% were from China and 10.9% from Korea, followed by North America (5.8%), Europe (4.3%), and Africa (1.5%). Although no significant differences were found regarding the history of dental treatment between international and non-international students (49.3% and 48.8%, respectively), international students had a significantly higher dental caries morbidity rate (60.1%) than non-international students (49.0%). The international students showed a significantly higher DMFT value compared with the non-international students: 5.0 and 4.0 per individual, respectively. Severe calculus deposition was observed in international students compared with non-international students (51.9% and 31.7%, respectively). Conclusions: The international university students had poorer oral health status than the non-international students, even though the result might include many uncertainties and possible biases.


annals of maxillofacial surgery | 2015

Postoperative evaluation of the folded pharyngeal flap operation for cleft palate patients with velopharyngeal insufficiency.

Hidemi Yoshimasu; Yutaka Sato; Takashi Mishimagi; Akihide Negishi

Background: Velopharyngeal function is very important for patients with cleft palate to acquire good speech. For patients with velopharyngeal insufficiency, prosthetic speech appliances and speech therapy are applied first, and then pharyngeal flap surgery to improve velopharyngeal function is performed in our hospital. The folded pharyngeal flap operation was first reported by Isshiki and Morimoto in 1975. We usually use a modification of the original method. Purpose: The purpose of this research was to introduce our method of the folded pharyngeal flap operation and report the results. Materials and Methods: The folded pharyngeal flap operation was performed for 110 patients with velopharyngeal insufficiency from 1982 to 2010. Of these, the 97 whose postoperative speech function was evaluated are reported. The cases included 61 males and 36 females, ranging in age from 7 to 50 years. The time from surgery to speech assessment ranged from 5 months to 6 years. In order to evaluate preoperative velopharyngeal function, assessment of speech by a trained speech pathologist, nasopharyngoscopy, and cephalometric radiography with contrast media were performed before surgery, and then the appropriate surgery was selected and performed. Postoperative velopharyngeal function was assessed by a trained speech pathologist. Results: Of the 97 patients who underwent the folded pharyngeal flap operation, 85 (87.6%) showed velopharyngeal competence, 8 (8.2%) showed marginal velopharyngeal incompetence, and only 2 (2.1%) showed velopharyngeal incompetence; in 2 cases (2.1%), hyponasality was present. Approximately 95% of patients showed improved velopharyngeal function. Conclusions: The folded pharyngeal flap operation based on appropriate preoperative assessment has been shown to be an effective method for the treatment of cleft palate patients with velopharyngeal insufficiency.


Oral Science International | 2005

Perception of Hypernasality and its Physical Correlates

Yukie Kozaki-Yamaguchi; Noriko Suzuki; Yukihiro Fujita; Hidemi Yoshimasu; Masato Akagi; Teruo Amagasa

Abstract To clarify the relationship between the perceptual diagnoses of hypernasality and its physical correlates, we conducted three experiments using the Japanese vowel /i/. We performed a spectral analysis of hypernasality on five cleft palate patients and six velum resection patients to investigate the spectral features related to hypernasality (experiment 1). Psychoacoustic experiments were conducted using various spectrally modified vowels to investigate the relationships between the spectral features and auditory perceptions of hypernasality (experiment 2). We analyzed the estimated spectral envelopes using an articulatory speech synthesis model to clarify the relationship between the spectral features and the velopharyngeal opening (experiment 3). Experiments 1 and 2 suggested four spectral features as the characteristics of hypernasality: (1) broadening of the F1 bandwidth, (2) an additional peak at around 1 kHz [P1], (3) a decrease in the magnitude of F2, and (4) a dip between F2 and F3 [D2]. In particular, the simultaneous modification of the decrease in the magnitudes of F2 and D2 is a very important cue for the auditory perception of hypernasality. Experiment 3 showed that the dips caused by nasal coupling resulted in the spectral modifications. In addition, the dip regions appeared to spread from the low-frequency region (around F1) to the high-frequency region (above F2), as the velopharyngeal opening enlarged. This suggests that the decrease in the magnitude of F2 and the dip between F2 and F3 [D2] are related to excessive acoustic coupling of the nasal cavity.


Journal of Japan Society for Oral Tumors | 1998

Postoperative speech function in patients of cancer of floor of mouth with immediate surgical reconstruction. An oncology group study.

Yukihiro Michiwaki; Ken-ichi Saitoh; Kohsuke Ohno; Kimie Mori; Yoshizumi Yamazaki; Harunobu Shima; Futoaki Matsubara; Mika Yokoyama; Ken-ichi Michi; Teruo Amagasa; Hidemi Yoshimasu; Hiroshi Iwaki; Takashi Fujibayashi; Yukihiko Kinoshita; Yoshiro Honma; Kanichi Seto; Masaro Matsuura; Katsunori Ishibashi; Kohichi Asada; Toru Satoh; Kiyohide Fujita; Satoshi Umino; Sadao Okabe

根治手術後に即時再建手術を行った口底癌19症例の術後の構音機能と手術との関連性を分析した。評価方法は日本語100語音による発語明瞭度検査である。対象症例の内訳を軟組織の再建方法別にみると, 遊離前腕皮弁移植症例が12例, 大胸筋皮弁移植症例と腹直筋皮弁移植症例がそれぞれ3例, 前腕皮弁と大胸筋皮弁の併用症例が1例であった。舌の切除範囲別では, 舌部分切除症例が14例, 可動部半側切除症例が1例, 半側切除症例が1例, 亜全摘出症例が3例であった。これらの症例について原発腫瘍の大きさ, 切除範囲, 切除様式, 軟組織の再建方法, 下顎骨の再建方法と術後の構音機能の関連について検討した。その結果, 原発腫瘍の大きさによる術後の構音機能の差は少なかったが, 舌の切除範囲が大きくなると構音機能は低下していた。切除様式については側方型の切除を受けた症例の明瞭度は前方型の切除を受けた症例よりも明らかに高く, 切除様式による発音機能の差異が明らかであった。前方型の切除を行った症例の術後の発音障害を防ぐためには, 手術法の改善が必要であり補綴物の応用が有用であることが示唆された。


The Journal of the Stomatological Society, Japan | 1988

[Clinical cytogenetic studies in patients with cleft lip and/or cleft palate. 1. G-banding technique].

Kenji Hashimoto; Ichiro Yamada; Hidemi Yoshimasu; Yasuo Kobayashi; Shigetoshi Shioda; Takashi Tamura; Yoshiyuki Hiraishi; Takayuki Nagaoka; Hisashi Hagiwara; Toshiyuki Furusho

Judging from the studies on twins with cleft lip and/or palate, it seems to be a fact that the disease is hereditary. According to previous studies, they reported that patients with cleft lip and/or palate showed almost the same pattern of inheritance as the multifactorial inheritance. However, as shown in the report (Tanaka et al., 1973) in which it assumed that it was the multifactorial inheritance, with regard to the morbidity rate there is a great difference between the observed value and the expected value. This does not always satisfy the assumption of multifactorial inheritance. We considered this point and tried the chromosome analysis using the G-band technique on three groups of cleft lip, cleft palate, and cleft lip and palate on included twelve subjects (two males and two females in each group) . That is, in this study approximately 550 bands were analyzed in detail and the results that they had no chromosome aberration were obtained. We think that the results do not mean that patients with clefts have no chromosome aberration, the problem being the chromosome banding technique we used. In order to investigate this point, we will make a study using the high-resolution banding technique to in the families which have sibs with cleft lip and/or palate and cases of twins with clefts.


Journal of medical and dental sciences | 2003

Effects of autologous serum on osteoblastic differentiation in human bone marrow cells

Noriyuki Yamamoto; Masatsugu Isobe; Akihide Negishi; Hidemi Yoshimasu; Hitoyata Shimokawa; Keiichi Ohya; Teruo Amagasa; Shohei Kasugai

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Teruo Amagasa

Tokyo Medical and Dental University

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Hiroshi Iwaki

Tokyo Medical and Dental University

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Shigetoshi Shioda

Tokyo Medical and Dental University

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Akiko Kobayashi

Tokyo Medical and Dental University

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Koji Kino

Tokyo Medical and Dental University

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Nobuyuki Tanaka

Tokyo Medical and Dental University

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Junichi Ishii

Tokyo Medical and Dental University

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Kenichi Tomitsuka

Tokyo Medical and Dental University

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Ichiro Ogura

Tokyo Medical and Dental University

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Masashi Yamashiro

Tokyo Medical and Dental University

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