• Maxillofacial Plastic and Reconstructive Surgery
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• v.42
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• pp.32.1-32.4
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• 2020

Background: Le Fort I osteotomy is a highly effective treatment for skeletal jaw deformities and is commonly performed. High Le Fort I osteotomy is a modified surgical procedure performed for improving the depression of the cheeks by setting the osteotomy higher than the conventional Le Fort I osteotomy. Developments in three-dimensional (3D) technology have popularized the use of 3D printers in various institutions, especially in orthognathic surgeries. In this study, we report a safe and inexpensive method of performing a high Le Fort I osteotomy using a novel 3D device and piezosurgery, which prevent tooth root injury without disturbing the operation field for patients with a short midface and long tooth roots. Results: A 17-year-old woman presented with facial asymmetry, mandibular protrusion, a short midface, and long tooth roots. We planned high Le Fort I osteotomy and bilateral sagittal split ramus osteotomy. Prevention of damage to the roots of the teeth and the infraorbital nerve and accurate determination of the posterior osteotomy line were crucial for clinical success. Le Fort I osteotomy using 3D devices has been reported previously but were particularly large in size for this case. Additionally, setting the fixing screw of the device was difficult, because of the risk of damage to the roots of the teeth. Therefore, a different surgical technique, other than the conventional Le Fort I osteotomy and 3D device, was required. The left and right parts of the 3D device were fabricated separately, to prevent any interference in the surgical field. Further, the 3D device was designed to accurately cover the bone surface from the piriform aperture to the infra-zygomatic crest with two fixation points (the anterior nasal spine and the piriform aperture), which ensured stabilization of the 3D device. The device is thin and does not interfere with the surgical field. Safe and accurate surgical performance is possible using this device and piezosurgery. The roots of the teeth and the infraorbital nerve were unharmed during the surgery. Conclusions: This device is considerably smaller than conventional devices and is a simple, low-cost, and efficient method for performing accurate high Le Fort I osteotomy.

• The korean journal of orthodontics
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• v.27 no.5 s.64
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• pp.683-696
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• 1997

Recently several growth factors such as $TGF-{\beta}1$, $TGF-{\beta}1$, PDGF, bFGF are known to play an important role in scar formation following adult tissue injury. But there is little known about the role of growth factors in fetal tissue healing without scar formation. Therefore the purpose of this study is to investigate the distribution of growth factors which we involved with scar formation in the artificially created cleft lip wound healing of fetuses. The author had undergone hysterotomy and created cleft lip-like defects on fetuses of New Zealand White Rabbit in mid-third trimester (24 days). Fetuses were divided into 3 groups (the repaired group, the unrepaired group and the sham-operated control group). At 1, 2, 3, 5, 7 days after procedure, the repaired, the unrepaired and the control groups were obtained by Caeserean section. After documenting the viability of fetuses, fetuses were photographed to compare size and facial morphology and sectioned for histological examination by H & E stain and spatial and temporal deposition of $TGF-{\beta}1$, $TGF-{\beta}2$, PDGF, bFGF by immunohistochemical method. The findings are summarized as follows 1. There were lack of inflammation and scar formation and neovascularity in the repaired and the unrepaired group during experimental periods. 2. The reepithelialization of the unrepaired group was slower than that of repaired group. 3. There were no differences of distribution of bFGF in the control, the repaired and the unrepaired group. 4. PDGF was increased at post-op. first and second day and decreased after post-op. third day. Eventually, there were no differences in the control, the repaired and the unrepaired group. 5. $TGF-{\beta}1$ and $TGF-{\beta}2$ were slightly increased at post-op. first and second day and decreased after post-op. third day. Eventually there were no differences in the control, the repaired and the unrepaired group. And $TGF-{\beta}2$ is more densely stained than $TGF-{\beta}1$.