Biomedical subjects

Kun Hwang

Publications and source records attributed to Kun Hwang.

At least 19 recordsLinked to original sources

PubMed2006

Analysis of nasal bone fractures; a six-year study of 503 patients.

The aim of this study is to classify the nasal bone fractures based on computed tomography (CT) analysis and patterns of the nasal bone fractures, and review 503 cases treated between 1998-2004 at the Department of Plastic Surgery, Inha University Hospital, Incheon, South Korea. The age, sex, etiology, associated injuries, pattern of fractures and treatments were reviewed and a radiographic study was analyzed. Plain simple radiographs of lateral and Waters view of the nasal bones combined with computed tomography scans were done. Nasal bone fractures were classified into six types: Type I) Simple without displacement; Type II) Simple with displacement/without telescoping; IIA; Unilateral; IIAs) Unilateral with septal fracture; IIB) Bilateral; IIBs) Bilateral with septal fracture; Type III) Comminuted with telescoping or depression. Diagnosis of nasal bone fractures were made positively by plain x-ray films in 82% of cases, negative finding was 9.5% and 8.5% of cases were suspicious of the fractures. Reliability of the plain film radiographs of the nasal bone fracture was 82% in this study. In the most of the fractured nasal bones (93%) the closed reduction was done, open reduction in 4% and no surgical intervention in 3%. Nasal reduction was carried out in average 6.5 days post the injury. The patterns of the nasal bones fractures classified by CT findings were type IIA (182 cases, 36%), IIBs (105 cases, 21%), IIB (90 cases, 18%), IIAs (66 cases, 13%), I (39 cases, 8%) and III (21 cases, 4.3%). We think the CT is necessary for diagnosing nasal bone fracture because the reliability of the plain film was only 82%.

Adolescent↗

PubMed2006

Relationship between depressor septi nasi muscle and dermocartilagenous ligament; anatomic study and clinical application.

The aim of this study is to elucidate the anatomical and functional relationship between dermocartilagenous ligament and depressor septi nasi muscle. The noses of four Korean adult cadavers were studied and total of 123 patients (96 women, 27 men) were operated. The Depressor septi nasi muscle inserted to the base and lateral surface of the medial crus of lower alar cartilage. Dermocartilagenous ligament extended posteriorly and met depressor septi nasi muscle. It was pulled downward by the depressor septi nasi muscle. In all 123 cases the nasal tips were elevated after the dermocartilagenous ligaments were severed. Nasolabial angles increased from 5 - 15 degrees and the noses were shortened. Our morphological study and clinical experience suggest strongly the dermocatilagenous ligament was pulled downward by the depressor septi nasal muscle. We believe the dermocatilagenous ligament acts as a depressor.

Adult↗

PubMed2006

Does the upper eyelid skin become thinner with age?

The aim of this study was to elucidate whether the thickness of the upper eyelid skin is affected by aging. The upper eyelid skins of 61 Korean women were subject to the study. Fusiform pieces of the skin, 3-mm wide, were obtained at the midpupillary line, 7 mm above the eyelashes, during blepharoplasty. The specimens were stained with hematoxylin and eosin. Thickness of the skin was measured by a micrometer under a microscope. It was substantially the same in all of the age groups. The thickness varied from 818 +/- 85 microm in subjects 60 years or older to 884 +/- 112 microm in subjects between 21-and 30-years old; the mean was 860 +/- 305 microm. Thickness of the epidermis varied from 46 +/- 6 microm in subjects between 41- and 50-years old to 52 +/- 10 microm in subjects between 31- and 40-years old; the mean was 49 +/- 9 microm. There were no significant differences among the age groups (P = 0.440). Thickness of the dermis varied from 771 +/- 78 microm in subjects older than 61 years to 834 +/- 112 microm in subjects between 21-and 30-years old; the mean was 811 +/- 117 microm. There were no significant differences between the age groups (P = 0.553). It is noticeable that upper eyelid skin thickness is not affected remarkably by aging.

Adolescent↗

PubMed2006

Innervation of the procerus muscle.

The aim of this study is to elucidate innervation of the procerus muscle, which is attributed mainly to transverse lines on the radix nasi and indirectly to glabella frown line. Twenty-three hemifaces of Korean adult cadavers were dissected. In all specimens, the procerus muscle was supplied by the buccal branch of the facial nerve, which coursed infraorbitally. The number of the buccal branches varied: three in 47.8%, two in 47.8%, and one in 4.4% of the specimens. The buccal branch crosses the intercanthal line (nasion to the medial canthus) at approximately lateral one third. The nerve entrance was within a circle with a diameter of 5 mm and its center located 9 mm lateral and 10 mm superior from nasion. It was about a midpoint of lateral half of intercanthal line and lower one third between the intercanthal line and tangential line of the supraorbital rim. The anatomical knowledge might be contributive to depletion of transverse lines on the nasal bridge and function of the procerus muscle.

Adult↗

PubMed2006

Facial-hypoglossal nerve anastomosis using laser nerve welding.

The aim of this study is to compare laser nerve welding to microsurgical suturing of hypoglossal-facial nerve anastomosis (HFA), and a result of immediate to delayed repair, and to evaluate the effect of laser nerve welding on HFA for reanimation of facial palsy. The first group of five rats underwent immediate HFA by microsurgical suturing and the second group of five rats by CO2 laser welding. The third group of five rats underwent delayed HFA by microsurgical suturing, and the fourth group of five rats by laser nerve welding. The fifth group of five rats served as controls, with intact hypoglossal and facial nerve. In all rats of the four different treatment groups, cholera toxin B subunit (CTb) was injected in the epineurium distal to the anastomosis site on the postoperative 6th week and in the normal hypoglossal nerve in the five rats of the control group. Neurons labeled CTb of hypoglossal nuclei were positive immunohistochemically, and the numbers were counted. In the immediate HFA groups, CTb-positive neurons were 751 +/- 247 in the laser welding group (n = 5) and 888 +/- 60 in the microsurgical suturing group (n = 5). There was no significant difference (P = 0.117). In the delayed HFA groups, CTb-positive neurons were 749 +/- 54 in the laser welding group (n = 5) and 590 +/- 169 in the microsurgical suturing group (n = 5). The difference was not significant (P = 0.116). There was no significant difference between immediate and delayed anastomosis in the laser welding group (P = 0.600), but there was significance between immediate and delayed anastomosis in the microsurgical suturing group (P = 0.009). Injected CTb in intact hypoglossal neurons (n = 5) were labeled 1,003 +/- 52. No dehiscence in the laser welding site of nerve anastomosis was seen at the time of re-exploration for injection of CTb in all 10 rats. This study shows that the regeneration of anastomosed hypoglossal-facial nerve was affected similarly by laser welding and microsurgical suturing, and more effective, especially in delayed repair.

Anastomosis, Surgical↗

PubMed2006

Cutaneous perforators of the forearm: anatomic study for clinical application.

We studied the distribution of constant cutaneous perforators of the forearm.A total of 25 amputated forearms of 13 Korean fresh cadavers were used for the study. The specimens were fixed in formaldehyde solution and phenol mixture in low concentration. Red latex was injected into the axillary arteries of 8 specimens, and lead oxide-gelatin mixture (radiopaque material) was given into another 8. And then the cutaneous perforators were isolated by dissection and radiographed. Free fasciocutaneous flaps with the pedicles of cutaneous perforators were exploited in 9 specimens. Two fasciocutaneous perforators were constant on the flexor surface and 3 on the extensor side. Most of the emerging points of 2 flexor perforators were within each circle, with 2.5 cm (87.5%) and 3.0 cm (75%) in diameter, respectively. Most of the emerging points of 3 extensor perforators were within each circle, with 2.0 cm (87.5%), 1.5 cm (75%), and 2.0 cm (87.5%) in diameter, respectively.A knowledge of constant perforators of the forearm is conducive to the free skin cutaneous flaps to be designed safely.

Cadaver↗

PubMed2006

Thickness of Korean upper eyelid skin at different levels.

This study aims at elucidating the thickness of the Korean upper eyelid at different levels. Left eyelids of 10 (9 males and 1 female) fresh Korean cadavers were dissected. Full thickness upper eyelids were cut and trichrome stained. The thickness was measured under a microscope.The thickness of upper eyelid skin varied at different levels. The thickest part of the upper eyelid is just below the eyebrow (D) (1.127 +/- 238 microm), and the thinnest skin is near the ciliary margin (A) (320 +/- 49 microm). The upper tarsal area (C) and mid tarsal area (B) are 832 +/- 213 and 703 +/- 103 microm, respectively. "A" area was significantly thinner than mid tarsal "B" area (P = 0.000). The skin above the tarsus was thicker than the "B" area, but there was no significant difference (P = 0.081). The skin just below the eyebrow, "D," was thicker than the upper tarsal border, "C" area (P = 0.011). The epidermis accounted for 11.2% of the entire skin near the ciliary margin. However, epidermis presented less (4.2-5.5%) of the whole skin at other levels (P = 0.000). The distance between ciliary margin and the point where the skin turns suddenly thicker was 1.89 +/- 0.23 mm. The size of the tarsal plate was 8.88 +/- 0.81 mm. These data of upper eyelid skin thickness may apply to Asian double fold surgery and also to full thickness skin donation for grafting.

Adult↗

PubMed2006

Innervation of upper orbicularis oris muscle.

The aim of this study is to elucidate the innervation of upper orbicularis oris muscle. The upper lips of 17 hemifaces of Korean adult cadavers were dissected. The number of nerve branches crossing and entering the outer margin of pars peripheralis and pars marginalis were counted, respectively. The location of ramifying point of the buccal branch was measured. The nerve branches crossing the outer margin of pars peripheralis were about 4 (3.71 +/- 1.05) on each side of the face and branches crossing the outer margin of pars marginalis was 4.65 +/- 1.46. About four (4.06 +/- 0.83) branches entering the pars marginalis were found. Most ramifying points (14/17, 82%) located within a circle of 5 mm in radius diameter and the center was at 12 mm lateral and 26 mm superior to the mouth corner. An anatomical knowledge might be contributive to understand a wrinkle depletion of the upper lip and function of the orbicularis oris muscle.

Adult↗

PubMed2006

The relationship of capsulopalpebral fascia with orbital septum of the lower eyelid: an anatomic study under magnification.

The aim of this study is to elucidate each insertion of the capsulopalpebral fascia (CPF) and orbital septum (OS) in the lower eyelid. Fifteen eyelid specimens were obtained from 15 Korean male adult cadavers for the study. Three parasagittal sections were made apart at medial limbus, midpupillary line and lateral limbus. The specimens were cut in 10-mum sections, stained with Masson-trichrome and observed under light microscopy. The head of the CPF split open superiorly and inferiorly wrapping around the inferior oblique muscle and met anteriorly. CPF inserted to the inferior border of the tarsus, merging the anterior border of the inferior tarsal muscles. OS blended with CPF most closely at 3.7-5.4 mm beneath the lower tarsal border: and differently at 3.7 +/- 0.7 mm on the medial limbus line, 4.3 +/- 0.8 mm on the midpupillary line and 5.4 +/- 1.0 mm on the lateral limbus line. The blending level is closer to the tarsus at the medial side than the lateral side. The closest distance between the lower tarsal border and the first identifiable smooth muscle nuclei of the inferior tarsal muscle was 2.1-2.7 mm, and differently 2.7 +/- 0.7 mm on the medial limbus line, 2.7 +/- 0.7 mm on the midpupillary line and 2.1 +/- 0.9 mm on the lateral limbus line. Precise anatomical understanding of OS and CPF may be conducive to the lower eyelid surgery.

Aged↗

PubMed2005

Hypothenar flap based on a cutaneous perforator branch of the ulnar artery: an anatomic study.

This study describes a constant cutaneous perforator branch of the ulnar artery of the hand and a hypothenar arterial flap based on it. Eighteen amputated hands of 10 fresh cadavers were used for the study. Red latex was injected into the axillary arteries of nine specimens and radiopaque lead oxide-gelatin mixture into the remaining nine. Then, the cutaneous perforator branch of the ulnar artery was identified by marginal dissection and radiographed. The cutaneous perforator branch was found constantly in all 18 specimens and was named the "hypothenar perforator" (HP). On radiograph, a coordinate was set up with an origin (pisiform), a transverse x (through the pisiform and hamate of the carpal bones), and a proximal to distal y (through the pisiform and 4th interdigital web) axes. The HP was situated at 10.1 +/- 3.6 mm lateral to the pisiform (on the x axis) and 20.0 +/- 7.0 mm distal (on the y axis). A hypothenar flap based on the HP is suitable for covering small defects of the fingers, and the donor site can be closed primarily.

Humans↗

PubMed2005

Cutaneous perforators of the upper arm and clinical applications.

The authors investigated the distribution of constant cutaneous perforators in the upper arm. A total of 20 amputated upper arms of 10 fresh Korean cadavers were used for the study. Red latex was injected into the axillary arteries of ten specimens and lead oxide-gelatin mixture (radiopaque material) in the other ten. The cutaneous perforators were then identified by dissection and radiography. The upper arm had several (range: 5.7 to 6.3) perforating arteries in the subfascial plane, but only four fasciocutaneous perforators were constant: one in the medial intermuscular septum and three in the lateral intermuscular septum. The constant medial perforators were included in a circle of 2.89 cm in diameter, the center of which was 8.9 cm above and 1.2 cm medial to the medial epicondyle. The mean length and diameter of the extended pedicle of the medial perforator was 2.78 cm and 0.94 mm, respectively. The lowermost constant lateral perforators were included in a circle of 2.44 cm in diameter, the center of which was 16.8 cm above and 0.5 cm medial to the lateral epicondyle. The mean length and diameter of the extended pedicle of the lateral perforator was 2.88 cm and 0.84 mm, respectively. A flap based on the perforator of the medial intermuscular septum is not as simple as with the lateral intermuscular perforator, but direct closure of the donor site is more favorable. It is safe to design a free skin flap with knowledge of its dominant perforator.

Arm↗

PubMed2005

Submental perforating artery: a culprit of bleeding during facelift.

The aim of the study was to elucidate the precise anatomical detail of the submental perforating artery (SPA) and avoid bleeding during the facelift operation or submental procedures. Latex-injected heads of eight fresh Korean cadavers (6 male, 2 female) were used. After the facial artery was found, the dissection was continued anteriorly, following the submental artery (SMA). When the SMA ran anteriorly about 15.5 mm (15.5 +/- 2.2 mm) from the facial artery and reached about halfway from the gonion to the menton, it gave off one or two perforating branches (SPA, mean number 1.6). The SPA ran upward and forward until it reached the skin. Diameter of the SPA at its beginning was 1.25 +/- 0.36 mm. The point of emergence of the SPA from the SMA was about halfway (49% +/- 14%) from the gonion to the menton, about 6 mm (6.1 +/- 1.9 mm) inferior to the lower border of mandible. The high risk of injuring the vessels during the facelift can be explained by the close vicinity of the SPA to the mandibular inferior border.

Aged↗

PubMed2005

Vulnerability of the inferior alveolar nerve and mental nerve during genioplasty: an anatomic study.

Microgenia or "small chin" is corrected by various techniques, such as insertion of an alloplastic implant, cartilage or bone grafting, or horizontal advancement osteotomy. Horizontal recession osteotomy is used in macrogenia. Particularly in a microgenic mandible, the mental foramen is unexpectedly nearer to the inferior border of the body. During sliding horizontal osteotomy of the mentum, the inferior alveolar nerve (IAN) and mental nerve are vulnerable to an injury. Thirty fresh hemimandibles were used for a study of the IAN. The IAN course was traced by serial sections at intervals of 5 mm. In 50 dry specimens the direction of the mandibular canal was evaluated by the photographs with a stick put into the mental foramen. The IAN in mandibular canal runs above the lower one-third of the mandibular body. The terminal mandibular canal locates at an average of 4.5 mm under the mental foramen, advances 5.0 mm anteriorly, loops, and ends at the foramen. The direction of the mandibular canal at the mental foramen was 39.4 degrees lateral, 67.2 degrees superior, and 80.2 degrees posterior. It is advisable for surgeons to keep the level of sliding osteotomy of the mentum at least 4.5 mm below the mental foramen to spare the IAN.

Cadaver↗

PubMed2005

Miniplate fixation of high condylar fracture and postoperative exercise regimen.

The aim of this report is to present three cases of high condylar fracture treated with vertical ramus osteotomy, miniplate fixation of fractured condylar neck, and free grafting. The authors also introduce a simple and easy postoperative exercise regimen. A submandibular incision is made and the ascending ramus divided between the sigmoid notch and the angle of the mandible. After the fragment is removed, the dislocated head of the condyle is readily visible and can be retrieved. The reconstructed osteotomized ramus and condylar head can now be reinserted through the wound and plated. Intermaxillary fixation with arch bar is used. The length of the fixation period is about 14 days after surgery. At the end of this period, the bracket is applied to maxillary incisors, the occlusion becomes stable and reproducible, and then aggressive jaw-opening exercise begins. On postoperative day 21, elastics are applied 24 hours a day. They are placed lightly during the daytime to assist guiding protrusion of the mandible. The patient is instructed to protrude the mandible and to open the mouth simultaneously. The exercise is modified to lateral movement. After the bracket is removed on postoperative day 28, the patient exercises the chin laterally without any guiding elastic fixation for approximately 1 week. This regimen can be widely used in ostectomy-osteosynthesis cases.

Adolescent↗

PubMed2005

Closed reduction of fractured anterior wall of the frontal bone.

The authors report two cases of closed reduction of the anterior wall of the frontal bone. In the first case, the fractured segment was successfully reduced with a small periosteal elevator. In the second case, a tip of the periosteal elevator was broken during maneuvering the fractured bone and lost into the sinus cavity. The sinus was opened to retrieve the broken piece and repaired by internal fixation. The technique has a few merits: (1) the procedure is simple; (2) the operation time is short; and (3) only a small incision is needed.

Adolescent↗

PubMed2005

Course of the masseteric nerve in masseter muscle.

The masseter muscle is often exploited by plastic and reconstructive surgeons in transposition operations to correct facial palsy. In benign masseteric hypertrophy, a neurectomy induces atrophy of the muscle and therefore a slender face. A clear understanding of the course of the masseteric nerve is essential in maneuvering the masseter muscle. Detailed dissection was performed on 48 head halves of Korean cadavers, and the inside of each masseter muscle was explored under the microscope with x10 magnification. The masseteric nerve ran anteriorly and inferiorly between the deep and the middle layers. The nerve was observed at 33+/-5.6 mm from the inferior border of the muscle on the anterior third vertical line of the masseter muscle and at 47+/-5.5 mm in the posterior third. The closest distance between the main nerve and the gonion was 32+/-4.1 mm. Approximately two thirds (69.6%) of the masseteric nerve intersected the artery. The safe limit is within 47 mm from the inferior border of the muscle on the posterior third vertical line and within radial 32 mm from the gonion.

Adult↗

PubMed2005

Horizontal branch of the supraorbital nerve and temporal branch of the facial nerve.

The aim of this article is to describe anatomical detail of the course and territory of the horizontal branch of the supraorbital nerve, which connects with temporal branch of the facial nerve. Eighteen hemifaces of Korean cadavers (11 male, 7 female) fixed in 10% formaldehyde solution were dissected. All 18 specimens had horizontal branch of the supraorbital nerve. The horizontal branch emerges out of the supraorbital foramen, runs upward about 12 mm, and then turns laterally at an angle of 104.7 degrees toward the end of the eyebrow. The average number of horizontal branches was 1.7 +/- 0.8. The skin boundary supplied by the horizontal branch was a circle with a diameter of 30 mm. The center was located at 30 mm lateral to the supraorbital foramen and 12 mm above. Grossly, the horizontal branch of the supraorbital nerve connected with the temporal branch of the facial nerve in 8 of 18 (44%) specimens. Microscopically, both nerve branches had common epineurium, but the perineuria were separated. The horizontal branch of the supraorbital nerve is in touch with the temporal branch of the facial nerve, and there are actual connections between them in 44% of cases.

Aged↗

PubMed2005

Anatomy of pectoral fascia in relation to subfascial mammary augmentation.

The aim of this study is to elucidate the anatomic details of the pectoral fascia in relation to subfascial breast augmentation.Thirty-two breasts of Korean cadavers were dissected and studied grossly and microscopically. The superficial pectoral fascia (SPF) was easily undermined and separated with an Agris-Dingman dissector. A gentle pushing force by the dissector could stretch the SPF and extend the subfascial pocket further at the lateral border of pectoralis major muscle (PM). The dissector head stayed inside the pocket, not perforating through the fascia. Near the inferior border of PM at the level of the sixth intercostal space, the dissection was hard to advance down beyond rectus abdominis muscle (RA). Yet a continuous vigorous dissection led into the subcutaneous layer of the abdominal wall over RA. The SPF is thick and continues to superficial axillary fascia at the lateral end of the muscle. At the inferior border of the PM (sixth intercostal space), however, the pectoral fascia became thin and feeble. The subfascial implants should be placed under the SPF, laterally beyond the lateral border of PM and inferiorly under the glandular tissue of the breast below the sixth intercostal space.

Adult↗