In Sik Yun

Yonsei University Hospital | YUHS

Background Capsular contracture is a significant concern in patients undergoing post-mastectomy radiotherapy (PMRT) following implant-based breast reconstruction. It negatively impacts cosmetic outcomes and can have a profound effect on the individual's quality of life. Our study aimed to explore whether the degree of capsular contracture varies ba...

Background This study analyzed the demographic characteristics of patients with facial palsy who were treated using either dynamic or static procedures. This study aimed to compare the frequency of procedure implementation and age distribution between the two groups. Methods This study retrospectively analyzed the medical records of patients treat...

A 14-year-old girl had a mid-facial trauma event caused by hitting an opening door and experienced discomfort and swelling of the columella and upper lip. Physical examination revealed mild tenderness on light palpation without any discomfort with upper lip movement. A computed tomography scan of the maxillofacial bones with three-dimensional recon...

This study aims to confirm the effectiveness and safety of a prabotulinumtoxin type A (praBTX-A) injection in patients with bruxism and masseter hypertrophy. The study included patients who ground or clenched their teeth while sleeping and had computed tomography (CT) scans that showed a maximum thickness of the masseter muscle of 15 mm or more. Th...

Purpose: Ear reconstruction is one of the most difficult areas in the field of reconstructive surgery. Due to limitations of the current practice, a novel method of auricular reconstruction is needed. Major advancements in three-dimensional (3D) printing technique have rendered the process of ear reconstruction more favorable. Herein, we present o...

BACKGROUND Endoscopic transorbital approach (ETOA) has been proposed as a minimally invasive technique for the treatment of skull base lesions located around mesial temporal lobe (MTL), mostly extra-axial pathology. OBJECTIVE To explore the feasibility of ETOA in accessing intraparenchymal MTL with cadaveric specimens and describe our initial clin...

Background The endoscopic transorbital approach (ETOA) was recently added to the neurosurgical armamentarium. Although this approach could result in less injury to normal brain tissue, shorter operation times, and smaller scars, its clinical applications have not been fully investigated. We, therefore, sought to share our unique experiences of expl...

Chondroitin sulfate (CS), the main component of cartilage extracellular matrix, has attracted attention as a biomaterial for cartilage tissue engineering. However, current CS hydrogel systems still have limitations for application in successful cartilage tissue engineering owing to their unsuitable degradation kinetics, insufficient mechanical simi...

Background The early diagnosis and treatment of skin and soft tissue infections caused by nontuberculous mycobacteria (NTM) are important, especially as infections with rapidly growing mycobacteria (RGM) are rare and difficult to diagnose and treat. Recently, we identified 22 cases of NTM infections; in this study, we suggest treatment strategies b...

The biocompatible polyurethane acrylate (PUA) nanopillars were fabricated by soft lithography using three different sizes of nanobeads (350, 500, and 1000 nm), and the human adipose-derived stem cells (hASCs) were cultured on the nanopillars. The hASCs and their various behaviors, such as cytoplasmic projections, migration, and morphology, were obs...

Nanoparticle-enhanced coatings of bone implants are a promising method to facilitate sustainable wound healing, leading to an increase in patient well-being. This article describes the in vitro characterization of osteoblast cells interacting with polyelectrolyte multilayers, which contain detonation nanodiamonds (NDs), as a novel class of carbon-b...

In article number 2000092, In Sik Yun, Jong‐Souk Yeo, and co‐workers show the quantitative relationship between nanotopography and cell spreading mediated by focal adhesions (FAs) using adipose‐derived stem cells (ASCs). Since FAs require a constant adhesive area to maintain cell attachment on nanotopography, larger FAs are supported by many smalle...

Nanotopography mimicking extracellular environments reportedly impact cell morphological changes; however, elucidating this relationship has been challenging. To control cellular responses using nanostructures, in this study, the quantitative relationship between nanotopography and cell spreading mediated by focal adhesions (FAs) is demonstrated us...

Positional plagiocephaly is increasing in infants. Positional plagiocephaly is an asymmetric deformation of skull due to various reasons; first birth, assisted labor, multiple pregnancy, prematurity, congenital muscular torticollis and position of head. Positional plagiocephaly can mostly be diagnosed clinically and by physical examinations. The si...

Objective: Sphenoid wing meningiomas (SWMs) can be treated with complete surgical resection and recent endoscopic transorbital approach (ETOA) offers one of minimally invasive alternatives. The authors compare the surgical outcome of ETOA and extended mini-pterional approach (eMPTA) for SWMs with osseous involvement. Methods: From October 2015 t...

Purpose Non-activated platelet-rich plasma (nPRP) slowly releases growth factors that induce bone regeneration. Adipose tissue-derived stem cells (ASCs) are also known to induce osteoblast differentiation. In this study, we investigated the combined effect of nPRP and ASC treatment compared with single therapy on bone regeneration. Methods Thirty...

Purpose: Relaxin (RLX) is a transforming growth factor-β1 (TGF-β1) antagonist that is believed to function as a potent collagen re-arranger and a major suppressor of extracellular matrix components. Adenoviruses (Ads) are accepted vectors for cancer gene therapy. However, repeated treatments of Ad are limited by short-term biological activity in v...

Objective: Trigeminal schwannomas are rare neoplasms with an incidence of less than 1% that require a comprehensive surgical strategy. These tumors can occur anywhere along the path of the trigeminal nerve, capable of extending intradurally into the middle and posterior fossae, and extracranially into the orbital, pterygopalatine, and infratempora...

Background: Cryptotia is a congenital anomaly in which the upper part of the retroauricular sulcus is absent and buried underneath the temporal skin. Various surgical techniques have been reported for the correction of cryptotia following Kubo's V-Y plasty in 1933. Conventional methods using a local skin flap, skin grafting, tissue expansion, Z-pl...

Background An increasing number of patients undergo genioplasty for esthetic purposes to correct micrognathism or retrognathism. However, these conditions are considered an important risk factor for snoring. The purpose of this study was to evaluate both esthetic improvement and functional changes of snoring symptoms in patients who underwent hat-s...

Ear reconstruction using three‐dimensional (3D) printing technique has been considered as a good substitute for conventional surgery, because it can provide custom‐made 3D framework. However, there are difficulties with its application in clinical use. Researchers have reported 3D scaffolds for ear cartilage regeneration, but the designs of the 3D...

Patients with large or ptotic breasts who undergo nipple-sparing mastectomy and direct-to-implant (DTI) reconstruction tend to exhibit poor esthetic outcomes. We present a combined vertical mastopexy-DTI technique that can be used to raise the nipple position and to improve esthetic outcomes. Using the combined vertical mastopexy-DTI technique, it...

Parry-Romberg syndrome is a rare neurocutaneous syndrome characterized by progressive shrinkage and degeneration of the tissues usually on only one side of the face. It is usually difficult to restore the facial contour due to skin tightness. In this case report, we report a forehead reconstruction with custom-made three-dimensional (3D) titanium i...

Introduction: Augmentation mammoplasty is one of the most popular aesthetic operations in the world. In Korea, one of the fillers used for breast augmentation is AQUAfilling®gel (Biomedica. spol, s,r,o, Czech Republic). AQUAfilling®gel is a hydrophilic gel composed of 98% sodium chloride solution (0.9%) and 2% cation copolyamide. Methods: This i...

Background: Congenital muscular torticollis is a common childhood musculoskeletal anomaly that might result in permanent craniofacial deformity, facial asymmetry, and changes in the cervical vertebrae, if not treated during early childhood. Although there have been many studies on cervical vertebral changes, their onset in children has not been pr...

Bone regeneration is a complex process influenced by various physiological factors. Platelet-rich plasma (PRP) contains many growth factors and has shown osteogenic effects. The PRP is usually activated before use. However, the authors showed that nonactivated PRP (nPRP) and activated PRP have comparable osteogenic effects in the previous study. Ge...

Purpose: Posttraumatic edema in facial bone fracture patients may interfere with the operation field and delay the schedule. Thus, swiftly reducing the edema alleviates patient discomfort and advances the operation date. Ice packing and compression bandages are often used for such a purpose, but such methods are often inconvenient for the face. In...

Background: Deformational plagiocephaly (DP) refers to cranial asymmetry resulting from uneven external forces. A strong association exists between DP and developmental delay. We investigated the effect of DP severity on developmental delay. Methods: Between 2010 and 2016, data from 155 patients with DP were reviewed retrospectively. Two indices...

Purpose: The combination of acellular dermal matrix (ADM) and split-thickness skin graft (STSG) has been widely adopted to overcome functional and cosmetic limitations of conventional STSG. In this study, we evaluated the efficacy of this combination using 2 types of ADM: cadaveric acellular dermal matrix (CDM) and bovine acellular dermal matrix (...

Background Relaxin is a transforming growth factor β1 antagonist. To determine the effects of relaxin on scar reduction, we investigated the scar remodeling process by injecting relaxin-expressing adenoviruses using a pig scar model. Methods Scars with full thickness were generated on the backs of Yorkshire pigs. Scars were divided into two groups...

Understanding the anatomy of the muscles and other structures of the chest is of great importance in breast surgery. We have conducted the first analysis of the overall variations and relationships among the pectoralis major (PM), inframammary fold (IMF), and pectoralis minor (Pm). We studied 30 patients and 10 cadavers, leading to a total of 50 br...

Background: Distraction osteogenesis has been used to correct sagittal craniosynostosis in various ways. The purpose of this study was to introduce three distraction osteogenesis procedures by describing four objective measurements. Methods: Fifty-four patients with sagittal synostosis were recruited and assigned to one of three therapeutic grou...

Background: Congenital muscular torticollis (CMT) is a benign condition. With early diagnosis and appropriate management, it can be cured completely, leaving no residual deformity. However, long-standing, untreated CMT can lead to permanent craniofacial deformities and asymmetry. Methods: Four adult patients presented to the author with long-sta...

Background: The purpose of this study was to determine the usefulness of serum alkaline phosphatase (ALP) and calcitonin in the follow-up of tumor volume changes in patients with craniofacial fibrous dysplasia. Methods: Twenty patients with isolated craniofacial fibrous dysplasia were included, who met our criteria for long-term follow-up. Three...

Background Studies of the ear-molding technique have emphasized the importance of initiating molding early to achieve the best results. In the present study, we describe the immediate effects and long-term outcomes of this technique, focusing on children who were older than the ideal age of treatment initiation. Methods Patients who visited our in...

Microcystic adnexal carcinoma (MAC) is a rare malignant cutaneous adenocarcinoma that typically occurs in the head and neck, particularly at the central face. There are only slightly more than 300 patients reported worldwide, and most patients occur in Caucasians. A 72-year-old man was referred to our hospital for definitive treatment of known MAC...

Purpose The effects of platelet-rich plasma (PRP) on improvement of bone regeneration have been widely investigated. However, use of a proper scaffold is also important to the delivery of bioactive materials. The aim of this study was to analyze the effects of PRP with acellular dermal matrix (ADM) as a bone substitute in a cranial defect model. Me...

Background: Perineal defects are commonly encountered during the treatment of conditions such as malignancy, infectious disease, and trauma. Covering large defects in the perineal area is challenging due to its complicated anatomy and the need for functional preservation. Methods: Fourteen patients who underwent reconstructive surgery with multi...

Red ginseng is well known for its angiogenic effects and its effect of increasing expression of vascular endothelial growth factors (VEGFs), but little experimental evidence has been published. In this study, we examined the effect of red ginseng using an ischemic flap model. Twenty male Sprague-Dawley rats were divided into two groups of 10. One g...

Background: Reduction malarplasty to correct prominent malar complex is popular in Asians. Despite the popularity of reduction malarplasty, most of the surgical methods applied are not selected according to the degree of zygoma protrusion. In this study, we analyzed the effectiveness of two different surgical procedures to clarify their appropriat...

The authors studied to demonstrate the efficacy of custom-made three-dimensional (3D)-printed titanium implants for reconstructing skull defects. From 2013 to 2015, 21 patients (8-62 years old, mean = 28.6-year old; 11 females and 10 males) with skull defects were treated. Total disease duration ranged from 6 to 168 months (mean = 33.6 months). The...

Background: One of the most common complications of total auricular reconstruction is delayed wound healing, which results in skin necrosis and exposure of the ear framework. Various options exist for salvage of the exposed ear framework. Methods: From January 2009 to May 2014, 149 patients underwent total auricular reconstruction using an autog...

Although platelet-rich plasma (PRP) is widely used to enhance bone graft survival, the effect of PRP itself on bone regeneration is unclear. Because activated PRP releases many growth factors in a bolus, there are controversies regarding the effect of activation of the PRP on bone regeneration. Thus, we studied the effect of activated versus nonact...

Purpose: Reconstruction after total maxillectomy with extensive orbital floor defects poses a significant challenge for the reconstruction. The aim of this study is to present the outcomes of orbital floor reconstruction using tensor fascia lata slings after total maxillectomy and to compare these results to orbital floor reconstruction using allo...

The regulation of apoptosis, proliferation, and migration of fibroblasts is altered in keloids. The 90-kDa heat shock protein (heat shock protein 90) is known to play a key role in such regulation. Therefore, the authors investigated whether the inhibition of heat shock protein 90 in keloid fibroblasts could induce apoptosis and attenuate keloid fi...

The fibula free flap has now become the most reliable and frequently used option for mandible reconstruction. Recently, three dimensional images and printing technologies are applied to mandibular reconstruction. We introduce our recent experience of mandibular reconstruction using three dimensionally planned fibula free flap in a patient with guns...

Distraction osteogenesis (DO) is a less daunting procedure than extensive cranial vault remodeling and has been used to correct sagittal craniosynostosis. The purposes of this study are to describe DO in combination with expansion and compression procedures and to report analytic results based on the cranial index (CI), volumetric measurement, and...

The regulation of apoptosis, proliferation, and migration of fibroblasts is altered in keloids. The 90-kDa heat shock protein (heat shock protein 90) is known to play a key role in such regulation. Therefore, the authors investigated whether the inhibition of heat shock protein 90 in keloid fibroblasts could induce apoptosis and attenuate keloid fi...

The purpose of this study is to evaluate the long-term results of flap volume change, swallowing capacity, speech intelligibility, and differences between vertical rectus musculocutaneous (VRAM) and anterolateral musculocutaneous (ALT) free flaps in total tongue reconstruction. We retrospectively analyzed the medical records of 31 patients who unde...

Background Source material used to fill calvarial defects includes autologous bones and synthetic alternatives. While autologous bone is preferable to synthetic material, autologous reconstruction is not always feasible due to defect size, unacceptable donor-site morbidity, and other issues. Today, advanced three-dimensional (3D) printing technique...

Helmet therapy is a non-surgical option for treating positional plagiocephaly, and its effectiveness has been validated by various researches. In addition to cranial flattening and asymmetry, ipsilateral prominence of the mid-face and relative anterior transposition of the ipsilateral ear is also common. Hence, we investigated the impact of helmet...

Purpose Microtia is congenital anomaly of external ear and the reconstruction method for the external ear of microtia patient was based on autogenous costal cartilage framework. The application of 3D printing technique in medical science has made more possibility of human tissue restoration, and we tried to apply this technique in auricular reconst...

Hepatocyte growth factor (HGF) is a potent angiogenic factor that can stimulate the production of blood vessels in ischemic tissue. We investigated whether gene therapy using HGF-expressing adenovirus could enhance skin flap survival. Sprague-Dawley rats were randomly divided into three groups. Rats were subdermally injected with HGF-expressing ade...

Background Currently, breast conservation therapy is commonly performed for the treatment of early breast cancer. Depending on the volume excised, patients may require volume replacement, even in cases of partial mastectomy. The use of the latissimus dorsi muscle is the standard method, but this procedure leaves an unfavorable scar on the donor sit...

Background Many options are available to cover a palatal defect, including local or free flaps. The objective of this study was to evaluate the usefulness of palatal mucoperiosteal island flap in covering a palatal defect after tumor excision. Methods Between October 2006 and July 2013, we identified 19 patients who underwent palatal reconstructio...

Nowadays, with advanced 3D printing techniques, the custom-made implant can be manufactured for the patient. Especially in skull reconstruction, it is difficult to design the implant due to complicated geometry. In large defect, an autograft is inappropriate to cover the defect due to donor morbidity. We present the process of manufacturing the 3D...

Background For patients with full thickness skin defects, autologous Split-thickness skin grafts (STSG) are generally regarded as the mainstay of treatment. However, skin grafts have some limitations, including undesirable outcomes resulting from scars, poor elasticity, and limitations in joint movement due to contractures. In this study, we presen...

Background Reconstruction of ischial pressure sore defects is challenging due to extensive bursas and high recurrence rates. In this study, we simultaneously applied a muscle flap that covered the exposed ischium and large bursa with sufficient muscular volume and a profunda femoris artery perforator fasciocutaneous flap for the management of ischi...

A number of factors can cause dark circles around the eyes including excessive pigmentation, thin and translucent lower eyelid skin overlying the orbicularis oculi muscle, and shadowing due to skin laxity and tear trough. Autologous fat graft is an effective method for the treatment of lower lid dark circles, but irregularities caused by leaving vi...

Composite grafts are suitable for facial reconstruction because of good color matching, low donor site morbidity, acceptable texture, and easy surgical techniques. However, their use is limited to small-sized defects and by unpredictable survival rates. As platelet-rich plasma (PRP) contains large numbers of growth factors and has been widely used...

Transport distraction osteogenesis (TDO) has been used in attempts to treat large calvarial defects but has, until now, lacked consistency and reliability. To achieve sufficient bone formation, the effect of TDO was compared to the effect of TDO combined with recombinant human bone morphogenic protein-2 (rhBMP-2). Fourteen dogs were divided into 2...

The shape of the hairline and the ratio of the forehead to the face are both important factors for a balanced and attractive face. Because males primarily have a hairline with a rectangular or M shape (a frontotemporal-recessed shape), females with such shapes often have a strong masculine image and appear older. Follicular unit (FU) transplantatio...

Classical flaps for perinasal defect reconstruction, such as forehead or nasolabial flaps, have some disadvantages involving limitations of the arc of rotation and two stages of surgery. However, a perforator-based flap is more versatile and allows freedom in flap design. We introduced our experience with reconstruction using a facial artery perfor...

In Asians, facial scars, even fine surgical scars, often can be conspicuous and uncomfortable. The authors used a topical silicone gel containing vitamin C on facial scars for the purpose of making the scar less distinct. The study enrolled 80 patients. For the experimental group, the topical silicone gel mixture containing vitamin C was applied fr...

In order to improve osseointegration for biomedical implants, it is crucial to understand the interactions between nanostructured surfaces and cells. In this study, TiO_2 nanowires were prepared via Vapor-Liquid-Solid (VLS) process with Sn as a metal catalyst in the tube furnace. Nanowires were grown with N_2 heat treatment with their size controll...

Robots have allowed head and neck surgeons to extirpate oropharyngeal tumors safely without the need for lip-split incision or mandibulotomy. Using robots in oropharyngeal reconstruction is new but essential for oropharyngeal defects that result from robotic tumor excision. We report our experience with robotic free-flap reconstruction of head and...

The typical clinical symptoms of glomus tumors are pain, tenderness, and sensitivity to temperature change, and the presence of these clinical findings is helpful in diagnosis. However, the tumors often pose diagnostic difficulty because of variations in presentation and the nonspecific symptoms of glomus tumors. To the best of our knowledge, few s...

Purpose: Asymmetric nostrils that develop after rhinoplasty may result in nasal tip deformity and result in patient dissatisfaction. No systemic study on methods for the correction of transformed nostrils has been reported. In the current study, asymmetric nostrils were classified according to the degree of asymmetry and the authors' experiences o...

Background: We performed robot-assisted neck dissection (RAND) via a modified face-lift (MFLA) or retroauricular approach for neck management and carried out free flap reconstruction via these approaches in patients with head and neck cancer. We assessed the feasibility of free flap reconstruction in patients who had undergone transoral resection...

Adipose-derived stem cells (ASCs) have positive effects in the wound healing process. To clarify whether ASCs positively mitigate scar formation in the wound remodeling process. Full-thickness skin defects were created on the dorsal skin of Yorkshire pigs. After the defects were transformed into early scars, ASCs were injected, and the same amount...

The anterolateral thigh (ALT) perforator flap has become a popular option for treating soft tissue defects of lower extremity reconstruction and can be combined with a segment of the vastus lateralis muscle. We present a comparison of the use of the ALT fasciocutaneous (ALT-FC) and myocutaneous flaps. We retrospectively reviewed patients in whom fr...

The world's first face transplantation was performed in France, in 2005. Since then, 21 cases of face transplantation have been performed. Face transplantation is one of the most prominent part of composite tissue allotransplantation (CTA) along with hand transplantation. Since these fields are not deal with life-saving organs, there are many argum...

Relaxin (RLX) has multiple vascular actions, including vasodilation and angiogenesis, which occur via induction of vascular endothelial growth factor (VEGF) expression. We generated a RLX-expressing (dE1-RGD/lacZ/RLX) adenovirus and investigated whether it enhances skin flap survival. Thirty Sprague-Dawley rats were divided into three groups: RLX-e...

Hair transplantation has been a highly effective technique in reducing wide foreheads and recontouring the hairline. To classify hairline contour in Asian women and to find a way to make an ideal and refined female hairline. The hairline contours of 234 female volunteers were classified into five groups. We measured the height and width of forehead...

After distraction osteogenesis of the midface using a rigid external distraction (RED) system, there is a high possibility that a relapse might occur due to an incomplete fixation during the consolidation period, and it is uncomfortable for the patients to wear a head frame for 2 to 3 months. There are also risks of trauma that are developing. To o...

Although there are many reports on the measurement of the paranasal sinuses, few studies examined the development of frontal sinus with three-dimensional computed tomography (CT), especially in children. In this study, we evaluated the normal development of frontal sinus in Asian children, and we also analyzed the height, length, and width of the f...

According to previous reports about the experimental study of transport disk distraction osteogenesis (TDDO) for the reconstruction of bone defects, TDDO showed great feasibility of successful bone regeneration. However, those studies had some limitations in their design and analysis of the results, either. In this report, we intended to verify the...

In many cases, Asians' noses are shorter; their nasal tips have a bulbous shape and typically lack the projection. To correct these problems, we completely dissected the alar cartilage in a three-dimensional manner by which the alar cartilage could be repositioned. Thus, no external force was exerted to the alar cartilage. For approximately 4 years...

To reconstruct the perineal region, including the urogenital and anal triangle that differ from each other in tissue characteristics and function, we applied pudendal artery perforator flaps with a bilobed flap design. This bilobed flap design could improve the arc of flap rotation and the mobility of the flap so it could cover wide and deep defect...

In head and neck cancer reconstruction, the transverse cervical artery is a good alternative vessel when the appropriate recipient vessels cannot be identified because of preoperative radiation and radical neck dissection. Selecting the appropriate recipient vein is essential for a successful intraoral reconstruction. We attempted to determine whic...

To objectively describe skin color, the Commission International d'Eclairage (CIE) L*a*b* color coordinates and melanin and erythema indexes are used. However, it was difficult to understand the relationship among these parameters and to convert them into each other. We introduced a new technique to measure L*a*b* color coordinates and the melanin...

We have introduced a less invasive, simple, and effective method for zygomatic fractures using percutaneous reduction with a Steinmann pin (S-pin) and temporary external suspension with a Kirschner wire (K-wire).For 2 years, 51 patients underwent first percutaneous reductions and then fixations, which is a method that we developed. After the S-pin...

Despite numerous improvements in the palatoplasty procedure, speech dysfunction tends to develop in many patients, requiring another surgery. In addition, vomer flaps have been used in palatoplasty in various shapes and on purposes. Nonetheless, they have been used mostly to cover the defect in wide and complete type of cleft palate. We introduce t...

As the survival rate of tongue cancer has increased, longer-term results of tongue reconstruction are also being considered. The aim of this study was to report the long-term outcomes of total glossectomy.Of 14 patients who underwent total glossectomy, 11 were reconstructed with the rectus abdominis musculocutaneous free flap and 3 with the anterol...