Biomedical subjects

T Yamaga

Publications and source records attributed to T Yamaga.

At least 37 records · Page 2Linked to original sources

PubMed1993

[An adult case of left ventricular-right atrial communication with a false aneurysm of membranous septum].

A case of left ventricular-right atrial (LV-RA) communication associated with a false aneurysm of membranous septum is presented. The patient was a 51-year-old woman. Using a left ventriculography this case was diagnosed preoperatively as LV-RA communication. We found that the right atrium was directly communicated with the left ventricle through a fibrous membranous aneurysm adhering to the septal leaflet of the tricuspid valve. It was suggested that a false aneurysm, made by jet lesion from the left ventricle, perforated to the right atrium. So the current case was considered an acquired infravaluvular type LV-RA communication formed in the course of the natural closure of the membranous ventricular septal defect.

Aneurysm, False↗

PubMed1993

A new sectional partial denture utilizing lock mechanism for an upper removable partial denture.

A new sectional partial denture utilizing lock mechanism (lock denture) has been developed. Utilizing the lock mechanism, two parts of sectional partial denture are locked together easily and tightly. A lock denture has been constructed for an upper removable partial denture, has been worn for over three months and has clinically been proven to obtain good function and esthetics.

Ameloblastoma↗

PubMed1993

Clinical studies on marginal gingiva around abutment tooth (Part 3). Effect of tannin-fluoride preparation on gingival health.

It was examined whether the tannin-fluoride preparation (HY preparation), which might have a caries-reductive, plaque inhibiting and astringent action, could reduce the incidence of gingival inflammation around abutment teeth. Zinc oxide eugenol cement mixed with the HY preparation was packed in the cavity prepared in the resin base facing the abutment tooth. Gingival crevicular fluid (Periotron units:GCF), gingival index (GI), plaque index (PlI) and probing depth around the abutment teeth were measured over a 3 month period. The following results were obtained: 1. GCF decreased at month 1 and showed low values at months 2 and 3. 2. GI showed a decreasing tendency. 3. PlI and probing depth did not show obvious changes. These results indicate that the tannin-fluoride preparation reduces gingival inflammation around abutment teeth.

Adolescent↗

PubMed1990

[Clinical studies on crevicular fluid of abutment tooth. 3. Effect of tannin-fluoride preparation on gingival health].

It was examined, in this study, whether the tannin-fluoride preparation (HY preparation), which might have a caries reductive, plaque inhibiting and astringent action, could reduce the incidence of gingival inflammation around abutment teeth for removable partial dentures. Zinc oxide eugenol cement mixed with HY preparation filled in the cavity prepared in the resin base facing the abutment tooth. Crevicular fluid (Periotron unit: GCF), gingival index (GI), plaque index (PII), probing depth and caries activity around the abutment tooth were measured during 12 months. The following results were obtained: 1. GCF decreased at 1 month later and showed low values at 2, 3, 6 and 12 months. 2. The percentage of low GI value showed an increasing tendency during the experimental period. 3. There was slight variation in PII and probing depth during the experimental period. 4. Caries activity showed a decreasing tendency. These results indicate that the tannin-fluoride preparation reduces not only caries activity but also gingival inflammation around abutment tooth.

Dental Abutments↗

PubMed1990

Clasping system with rotational path of insertion. 2. Relation between mesio-distal distance of edentulous space and retentive force.

The rotational path of insertion differs substantially from the conventional path or perpendicular path of insertion. With a rotational path, one segment of the partial denture is seated first, then the remainder of it is rotated into position. One segment of this system is the rigid retentive component with a long occlusal rest and the other is the conventional clasp. This study examined the influence of mesio-distal distance of the edentulous space, the point of the displacing force, the undercut of rigid retentive component and the inclination of the abutment tooth on the retention of this system. The following results were obtained: 1) Retention of the denture was the lowest when a displacing force was applied at the conventional clasp part under the conditions of mesio-distal distances with edentulous spaces of 10, 20 and 30 mm, respectively. 3) Retention showed a tendency to decrease progressively as the proximal undercut on the rigid retentive component was changed to 2.0, 1.5, 1.0 and 0.5 mm, respectively. The values of the decreasing ratio of retentive forces were almost the same regardless of the mesio-distal distance of the edentulous space. 4) Retention of the denture was improved when a tilted tooth was used as an abutment tooth on the rigid retentive component side.

Dental Clasps↗

PubMed1990

[Gypsum temporary filling material containing HY-agent. The effects of the HY-agent on the dentin].

The effects of the Tannin-Fluoride preparation, called the HY-agent, on dentin substrate were examined by immersion of the dentin previously treated with HY-agent into the calcifying fluid at 37 degrees C. The changes in the nature of the dentin surface and penetration of elements in the dentin were observed. CaF2 was formed on the dentin as a result of a reaction between F, an element of the HY-agent, and Ca which precipitated from the calcifying fluid. This observation was confirmed by means of the X-ray diffraction method. Penetration of F, Zn, Sr and Ca into dentin was confirmed by the use of an electron probe X-ray microanalyser (EPMA). Application of the HY-agent to the dentin for sevendays increased the hardness of the dentin about 10%. Application of the HY-agent to the dentin for sevendays increased the contact angle about 3%. These results suggested that the organic and inorganic matter in dentin can be stabilized effectively both chemically and physically by treatment with an HY-agent.

Calcium Sulfate↗

PubMed1990

[Three cases of spontaneous rupture of the oesophagus (Boerhaave's syndrome)].

We reported three cases of spontaneous rupture which were surgically treated with direct suture method. One patient was operated on within eight hours after rupture with good results. In two patients diagnoses were made more than two days after rupture. One had esophageal fistula, but completely recovered after cervical oesophageal fistula, and another died of multiple organ failure. In this syndrome, early diagnosis and surgical treatment are essential for acceptable results. For early diagnosis, we emphasized on the presence of roentgenologic mediastinal and cervical emphysema. In patients for whom diagnosis was delayed and post-operative leakage at the oesophageal suture line occurred, temporarily fistulation of the cervical oesophagus proved to be effective in exclusion and diversion of the ruptured segment.

Adult↗

PubMed1989

Clinical studies on marginal gingiva around the abutment tooth. 2. Gingival health around proximal surface area adjacent to edentulous space.

Sixty subjects (42 subjects with dentures and 18 subjects without dentures) participated in this study. Crevicular fluid flow (Periotron unit: CGF), gingival index (GI), plaque index (P1I) and probing depth (PD) of 209 marginal gingiva around the proximal surface area adjacent to the edentulous space of natural and crowned abutment teeth were measured to evaluate gingival health. The following results were obtained. 1. The GI, P1I and PD in the subjects with dentures were higher than those in the subjects without dentures. The GCF in the subjects with dentures was inclined to be higher when compared to that in the subjects without dentures. 2. In the subjects with dentures, the GCF, GI and PD of crowned teeth were higher than those of natural teeth. On the other hand, in the subjects without dentures, the GCF, GI and PD of crowned teeth were almost equal to those of natural teeth.

Adult↗

PubMed1989

[A case of dumbbell neurogenic tumors of the mediastinum].

A 49-year-old man was admitted for the further examination of the abnormal shadow of the left posterior mediastinum, which was incidentally detected on routine chest X-ray. He has no complaints, and no abnormalities on neurological examination. Thoracic spine X-ray showed the destruction of the T12 vertebral body and the dilatation of the left intervertebral foramen between T12 and L1. Myelography showed no abnormalities, but contrast-enhanced CT scanned just after myelography revealed the extradural dumbbell-formed tumor. One stage removal of the tumor was safely performed through left posterolateral thoracotomy and transthoracic partial laminectomy. Postoperative course was uneventful. The tumor was histologically schwannoma, originated from the left thoracic sympathetic trunk. We think that this procedure is available for the operation of a kind of dumbbell tumor of the posterior mediastinum.

Humans↗

PubMed1989

[A case report of complete heart block by metastatic cardiac involvement from lung cancer].

A 77-year-old man who developed Adams-Stokes syndrome due to metastatic squamous cell carcinoma of the His-bundle was reported. There was a small primary lesion in the left upper lobe (S5) of the lung, and it widely invaded to the chest wall and metastasized to the spleen and the ventricular septum of the heart. The clinical diagnosis of the metastatic cardiac involvement is often elusive. But some literatures suggested that the careful observation of serial ECGs and UCGs were very useful not only to diagnose the metastasis but to indicate the invasive style to the heart.

Aged↗

PubMed1988