T Yamada

Okayama University, Okayama-shi, Okayama-ken, Japan

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Publications (4)5.21 Total impact

  • Article: Application of a novel method to analyse lip motion of cleft lip patients before and after lip repair.
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    ABSTRACT: The aim of this study was to apply a novel method to the analysis of lip motion in patients with bilateral cleft lip and palate before and after lip repair with cross-lip flaps, and to compare lip motion between the patients and healthy volunteers. Two 17-year-old bilateral cleft lip patients (one male and one female) who underwent lip repair with an Abbé flap and six healthy volunteers were enrolled in the study. Motion images from three infrared and one colour digital video camera were captured on a personal computer. By applying a multiple-baseline stereo, range images were produced across the whole images. Lip motion during phonation was then analysed as follows. The lips were divided into eight areas as designated by landmarks and Bézier curved lines, and virtual grid intersections set on the range images were calculated. The lip motion was divided into four periods along a time axis and the velocities were then calculated. The mobility of the prolabium increased following surgery in both patients. Changes in the ratio of movement of the upper vermilion to the lower vermilion, before vs after surgery, differed in both patients. The timing of the maximal speed during lip motion varied in both patients before and after surgery, and in the healthy volunteers.
    Dentomaxillofacial Radiology 06/2009; 38(4):232-8. · 1.08 Impact Factor
  • Article: Effect of ENU (ethylnitrosourea) mutagenesis in cleft lip and/or palate pathogenesis in mice.
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    ABSTRACT: Cleft lip and/or palate (CL/P) are caused by many factors. The aim of this study was to investigate the effects of genetic point mutations in CL/P pathogenesis. ICR and AJ strain mice were used. Ethylnitrosourea (ENU) was injected into 10-week-old male mice (G0) intraperitoneally at a dose of 250 mg/kg. The males were bred with two untreated virgin females of the same strain on day 100 after injection. The uterine contents (G1) of one female were examined on day 18.5 of pregnancy. From the other female, the offspring were delivered naturally, and F3 mice (G3) were also examined in the same way. In ICR strain mice, cleft palate only (CPO) was increased in both the G1 and G3. The frequency was significantly higher in the G3 than the G1 generation. Cleft lip was not observed. In AJ strain mice, CL/P increased in both the G1 and G3. In the G3, the frequency of CPO was increased significantly. Genes related to CPO may be recessive in phenotype. CPO and cleft lip differ from a genetic viewpoint. Point mutations play a significant role in cleft lip and palate.
    International Journal of Oral and Maxillofacial Surgery 02/2005; 34(1):74-7. · 1.51 Impact Factor
  • Article: Evaluation of respiratory status and mandibular movement after total temporomandibular joint replacement in patients with rheumatoid arthritis.
    K Mishima, T Yamada, T Sugahara
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    ABSTRACT: We performed total TMJ replacement to improve respiratory status and correct occlusion in six patients with destruction of the temporomandibular joint (TMJ) caused by rheumatoid arthritis. Morphological changes were evaluated on lateral cephalograms before and after surgery. Respiratory function and mandibular movement were assessed with the use of an apnea-monitor and an LED mandibular tracking device, respectively. After surgery, symptoms such as snoring and daytime sleepiness improved, and solid food could be masticated. Postoperative cephalograms showed that both the posterior airway space and ramal height were significantly improved by surgery. Postoperative records of mandibular movement indicated stability of the occlusion and improvement of mandibular movement, as compared with the preoperative records. Mean oxygen saturation significantly improved 1 month after surgery, whereas apnea and apnea-hypopnea indices did not change significantly.
    International Journal of Oral and Maxillofacial Surgery 07/2003; 32(3):275-9. · 1.51 Impact Factor
  • Article: Lyapunov Exponents for Japanese Vowels in Normal Adult and Cleft Palate Speakers
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    ABSTRACT: Objective: The purpose of this study was to explore the possibility of using Lyapunov exponents (LE) to evaluate the voice and speech in cleft palate (CP) patients. Subjects and Methods: Fifty healthy adults (25 males and 25 females) and 17 adult patients (10 males and 7 females) with repaired CP, who had no hypernasality, were enrolled. Five Japanese vowels were recorded at 44.1 kHz. Nasalance scores were measured simultaneously. The first LE was computed for each 1-second interval, and the mean for the first LE from all intervals (mLE1) was then calculated. The delay time and embedding dimension were estimated at 13, 40, 34, 27 and 22 points for the vowels /a/, /i/, /u/, /e/ and /o/, respectively, and at 8 points for all vowels. Results: The mLE1s for all vowels did not differ between normal males and females. The mLE1s for /a/ were significantly higher both in males and females with CP than in normal individuals. The correlation coefficient between the mLE1s and nasalance scores for all vowels was not significant for both normal and CP subjects. Conclusion: The LE seemed to be related to pathological disorders of the vocal cords in CP patients, but was independent of resonance parameters.
    Folia Phoniatrica et Logopaedica 08/1970; 63(3):129-133. · 1.12 Impact Factor

Institutions

  • 2003–2009
    • Okayama University
      • Department of Oral and Maxillofacial Reconstructive Surgery
      Okayama-shi, Okayama-ken, Japan