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Biomedical subjects

Junichi Takayama

Publications and source records attributed to Junichi Takayama.

6 recordsLinked to original sources

[Observations on three dimensional images for cracks of doweled teeth--comparison of images from specimen sections and dental tomograms from small three dimensional X-ray CT].

PURPOSE: Intraoral views of teeth with dowel and post hole taken by small three-dimensional X-ray CT (3DX) were compared with three-dimensional images from specimen sections of the same extracted teeth. This comparison shows the usefulness of 3DX for examination of cracked teeth in the oral cavity. MATERIALS AND METHODS: After taking dental tomographic images using 3DX for fractured teeth in the oral cavity, the fractured teeth were extracted and three-dimensional images for them and their cracks were obtained from a set of photographed sections. Then both sets of three-dimensional images for the fractured teeth were compared in terms of the form and region of the cracks. DISCUSSION: The tooth cracks were observed at the root face region in the intraoral view. Also, in the extracted teeth, fracture lines were recognized from the three-dimensional images. Moreover, a discontinuous image was obtained in teeth from the dental tomographic image using 3DX. This discontinuous image in teeth was observed in the same region and direction as the cracks of the three dimensional image from specimen sections of the extracted teeth. CONCLUSIONS: The discontinuous images of teeth in the dental tomographic images from 3DX were observed in the same region and direction as the cracks of teeth in the three-dimensional images from specimen sections of the extracted teeth. It was confirmed that dental tomographic images from 3DX are useful for finding cracks in living teeth. However, dental tomographic images from small three-dimensional X-ray CT are not perfectly reliable because the discontinuous image is not found in some teeth where the cracks are recognized by images from specimen sections after extraction.

Humans↗

Clinical benefits in endoscopic thyroidectomy by the axillary approach.

BACKGROUND: Surgical treatments for thyroid diseases require skin incisions that can result in prominent scars, complaints resulting from adhesions, hypesthesia, and paresthesia in the neck. We have developed an endoscopic thyroidectomy using an axillary approach. In this article, we compare our original technique with conventional open surgery from the aspects of surgical invasiveness and patients' complaints after surgery. STUDY DESIGN: Each procedure was performed in 20 patients with follicular tumors. The two groups were similar for age, gender, and the mean diameter of the thyroid tumor. No statistically significant difference in the final pathological diagnosis was found between the two groups. Surgical invasiveness and patients' complaints after surgery were compared using results of the operation and a questionnaire. RESULTS: The operating time for open surgery was significantly shorter than that for endoscopic surgery (p < 0.01). In the endoscopic surgery group, the patient questionnaires revealed that 4 patients had severe anterior chest pain on the first postoperative day. The postoperative pain decreased after, and we could not find any difference between the two groups with regard to postoperative pain. Three months after surgery, one patient who had received an endoscopic procedure complained of slight hypesthesia, and none of the patients complained of discomfort while swallowing. Among the patients who underwent open surgery, 13 patients (65%; p < 0.01) complained of hypesthesia or paresthesia and 6 patients (30%; p < 0.05) complained of discomfort while swallowing. All of the patients treated using the endoscopic procedure were satisfied with the cosmetic results, but 15 patients who underwent open surgery complained of unsatisfactory cosmetic results (p < 0.01). CONCLUSIONS: The incidence of postoperative complaints after endoscopic surgery is considerably lower than that after open surgery.

Adult↗

Direct mini-incision thyroidectomy.

We recently developed a new surgical technique for carrying out thyroidectomy, to minimize surgical invasiveness and improve the cosmetic result. Our procedure differs from conventional thyroidectomy in requiring a 3-cm skin incision and no raising of the skin flap. Since this technique decreased tissue trauma by obviating unnecessary neck exploration, hypesthesia or paresthesia in the neck and discomfort while swallowing, related to a large skin incision and raising of the skin flap, are minimized. Since thyroidectomy is performed after delivering the thyroid gland through the small skin incision, sufficient exposure for dissection of the pretracheal and paratracheal space can be obtained. Therefore, injuring the recurrent laryngeal nerve and the parathyroid gland can be avoided. Although the number of patients that we have treated in this manner is still small, we believe that our new procedure constitutes a useful surgical treatment for patients with thyroid disease.

Adult↗

Direct mini-incision parathyroidectomy.

We describe our technique for performing a mini-incision parathyroidectomy in patients with hyperparathyroidism. Since our procedure differs from conventional parathyroidectomy in requiring a 2- or 3-cm skin incision and no raising of skin flap, this technique resulted in a good cosmetic status and less invasiveness. Hypesthesia or paresthesia in the neck and discomfort while swallowing related to a large skin incision and raising of skin flap are minimized. Although the cosmetic results of endoscopic techniques are better than those of our procedures, endoscopic instruments remain traumatic, can easily inflict iatrogenic lesions to parathyroid adenomas and enhance the risk of tumor cell exfoliation, especially if the parathyroid adenoma is manipulated by the instruments. Our surgical procedure can be less technically demanding and time-consuming. Although the number of patients whom we have treated in this manner is still small, we believe that our new procedure constitutes a useful surgical treatment for hyperparathyroidism.

Humans↗