Biomedical subjects
Publications and source records attributed to T Takato.
The positive rate of infectious diseases (syphilis, hepatitis B and C) in in-patients at the department of oral surgery was investigated for five years. Each positive rate of them was 2.4% for STS, (1.3% for TPHA), 0.6% for HBs antigen, 3.2% for HCV antibody, respectively. These results suggest that it is important to perform universal precaution in the treatment room.
Recently, the Er: YAG laser has attracted attention because of its possibility of cutting hard tissue with extremely small thermal injuries. In this paper, eight cases (thirteen teeth) of apicoectomy using Er: YAG laser are reported. All procedures were performed without using air turbin or electric drill. The advantages of Er: YAG laser application include: absence of uncomfortable vibration: less chance for contamination of the surgical site: and reduced risk of trauma of adjacent tissue compared with ordinary methods.
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PURPOSE: The purpose of this study was to describe the clinical and radiographic observations on cantilever iliac bone grafts for reconstruction of cleft lip-associated nasal deformities. MATERIALS AND METHODS: Cantilever iliac bone grafts were performed on 14 patients with a severely deformed cleft lip-associated nose using the open rhinoplasty technique. An approximately 6-cm length of iliac bone was tightly inserted into a subperiosteal pocket over the nasal bones, and the nasal tip was elevated by the distal end of the graft. The clinical follow-up ranged from 7 months to 3 years. RESULTS: All patients were judged to have satisfactory results. The grafted bone decreased slightly in size during the first 2 to 3 months, and irregularities in contour became rounded. During the same period, bony union with the underlying nasal bones was observed in all cases. After about 6 months, further changes did not occur in the grafts. CONCLUSION: This type of bone graft can be used for additional structural support and to achieve the desired nasal projection and profile. Augmenting the nasal bridge creates the illusion of a narrower nose. The key to success of the operation seems to be the proper fixation of the grafted bone to the underlying nasal bones.
PURPOSE: This article describes the technique of columellar lengthening using a cartilaginous strut in patients with a severely deformed bilateral cleft lip-associated nose. MATERIALS AND METHODS: When the upper lip is not deficient, and especially when resection of lip scar tissue is indicated, the Millard forked flap technique is recommended. Advancement of the prolabium into the columella for lengthening, combined with an Abbé flap for upper lip reconstruction, is indicated when a deficient upper lip is unable to provide adequate donor tissue. A cartilaginous strut is inserted behind the forked flap or the advanced prolabium. According to the age of the patient, septal cartilage, costal cartilage, or ear cartilage is selected. Ten patients with a severely deformed bilateral cleft lip-associated nose underwent these procedures. RESULTS: In each case, the columella was lengthened satisfactorily. In four patients, the scar became hypertrophic at the base of the columella and scar revision was performed secondarily. CONCLUSIONS: A cartilaginous strut is the key to avoiding the tendency toward retraction or thickening of the lengthened columella. It gives a slight lift to the tip, provides more definition, and improves the columellar contour.
PURPOSE: To review a 10-year follow-up of cases with rhinoplasty for a cleft lip-associated nose deformity done during the preschool years. MATERIALS AND METHODS: Sixteen patients from 16 to 19 years of age were evaluated with two indices: the nasal index and the lobule portion of the columella index. RESULTS: Several years after surgery the results appeared to be reasonably satisfactory. However, as the patients approached their adolescent growth spurt at 15 years of age, undesirable features became obvious. Each patient showed a strikingly bulbous nose. The nasal index of male patients ranged from 68.8% to 82.7% (mean, 75.4%) and that of female patients ranged from 72.7% to 85.0% (mean, 79.2%). The mean value of the nasal index in the Japanese male and female is 58.5% +/- 1.5% and 59.0% +/- 1.0%, respectively. The lobule portion index of male patients ranged from 57.1% to 72.0% (mean, 65.1%) and that of female patients ranged from 62.5% to 82.0% (mean, 74.2%). The lobule portion of the columella constitutes 33% of the total columellar length on average. CONCLUSIONS: A possible cause of the undesirable deformities is use of an open surgical method. A second possible cause is mobilization and suspension of the alar cartilages. These undesirable features may occur only in Oriental noses.
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We describe our technique for correcting a cleft lip nasal deformity using L-shaped iliac bone grafts to achieve additional structural support and the desired nasal projection and profile. Augmenting the nasal bridge creates the illusion of a narrower nose. Further, the columellar portion of the L-shaped graft provides stabilization, eliminating the "see-saw" effect of the bridge graft on the fulcrum of the bony bridge, which can lead to a depressed tip and loss of the root indentation. Clinical and radiographic observation has revealed that this method of correction has consistently produced satisfactory results.
The process of bone formation in mandibular lengthening by distraction was studied in 30 rabbits. The mandible was subjected to a corticotomy, held in a neutral position for 2 weeks, and then lengthened at 0.18 mm per 12 hours for 24 days using a unilateral external fixation device (Orthofix M-100). On completion of the distraction, x-ray analysis showed that the distracted gap was filled with callus organized into three zones, namely, two sclerotic zones with a central radiolucent zone. These zones became indistinguishable from the adjacent preexisting mandible at 10 weeks after distraction. Histologically, new bone, which was formed by both intramembranous and endochondral ossification, underwent remodeling and resulted in cortical bone by 8 to 10 weeks after completion of distraction.
The patients referred from our hospital at the Department of Oral Surgery, University of Tokyo, during the two years from January 1990 to December 1991 were analyzed statistically. The results were as follows: 1. Our subjects were 1,152 patients (24.2% of first-time patients), 540 males and 612 females. 2. Concerning age distribution, the majority was in their forties, fifties and sixties. 3. More patients were from internal medicine, ENT clinic, plastic surgery and cardiothoracic surgery. 4. On the number of patients categorized by disease at other departments, the largest number was cardiovascular disease. 5. On the number of patients categorized by disease at our department, the majority were dental diseases (dental caries, marginal periodontitis and missing teeth).
Emergency patients at the Department of Oral Surgery, University of Tokyo, during the three years from January 1990 to December 1992 were analyzed statistically. The results were as follows: 1. The total number of emergency patients was 209 and tended to increase with the advance in years. 2. There were a few more males than females and most of the patients ages were in the twenties. 3. The disease causes were dental caries or periodontal disease in 95 (45.5%), trauma in 58 (27.8%), and inflammation in 32 patients (15.3%). 4. It is clear that a system of oral emergency treatment is necessary.
The growth potential of a free graft of an epiphysial plate was investigated in rabbits. Two epiphysial plate grafts were harvested from each iliac crest. One was grafted to the head (onto bone) and the other to the ear (onto cartilage). Both of the epiphysial plates enlarged to a maximum height of 1.4 cm and became similar to iliac crests. Enchondral ossification was observed up till approximately 28 weeks of age. We conclude that an epiphysial plate has growth potential after free heterotopic transplantation.
Prefabrication is a method for creating donor flaps by implantation of a nourishing pedicle prior to harvesting the flap. Based on the concept that implantation of a "flow-through" vein results in sufficient vascularisation to support a skin flap, we used a rabbit model to investigate the viability of prefabricated total venous perfusion (TVP) flaps. Prefabrication of an abdominal wall donor site was performed using the left epigastric vein in 25 male New Zealand white rabbits. An 8 x 10 cm skin flap was elevated 1, 2, 3, 4, and 6 weeks after prefabrication (n = 5 per group). A silicone sheet was implanted under the skin flap. The mean survival rate of skin flaps was 24%, 52%, 87%, 83%, 84%, respectively. Results of this study show that reproducible survival of a prefabricated TVP flap can be obtained when the flap is elevated more than 3 weeks after prefabrication.
Bone lengthening in the upper and lower extremities by gradual distraction has become an accepted procedure. We have used an extraoral device to lengthen the mandible in four patients with unilateral mandibular hypoplasia. Using an accurate skull replica, the proposed corticotomy line, intended direction of lengthening, and appropriate position for the screws were determined. Following distraction, a significant increase in the dimensions of the affected mandible was obtained in each case. In this series, accurate skull replicas proved very useful for defining the anatomy, for surgical simulation and for pre- and postoperative evaluation.
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Prefabrication of a flap may represent a new alternative, not limited by natural vascular territories, for creating donor sites. Experimental procedures in which an A-V shunt results in sufficient flap neovascularization have been reported. This study was undertaken to investigate how neovascularization from the recipient bed affects survival of this type of flap. An 8-cm x 10-cm prefabricated skin flap, nourished by the left epigastric vein, was constructed in a rabbit abdomen. In half the models, a silicone sheet was placed under the flap, to impede neovascularization from the bed. The flaps of both experimental groups showed excellent viability, and no statistically significant difference in survival rate was recognized. This flap was found to be independent of the vascularity of the underlying bed.
The gluteal thigh flap first reported by Hurwitz in 1980 can provide a large reliable flap for coverage of the sacrogluteal and perineal regions. This flap can be extended quite some way along its axial inferior gluteal vessels, but its width is limited to approximately 10 cm if direct approximation of the donor site defect is required. In this article, we report a U-shaped modification of the gluteal thigh flap for efficient use of the flap in covering a large defect in the sacrogluteal region.