Se Ho Hwang

Location and nature of retro-orbicularis oculus fat and suborbicularis oculi fat.

The aim of this study is to elucidate the anatomic location and histologic nature of the retro-orbicularis oculus fat (ROOF) and suborbicularis oculi fat (SOOF) around the orbital area. Seventeen hemifaces of 12 Korean adult cadavers were used. ROOF and SOOF were observed in all specimens. ROOF was located in a supraorbital area within a range of between a medial +41 and a lateral −39 degrees to a vertical midpupillary line. The shape is crescent and almost symmetric when folded in half. The horizontal length of ROOF was approximately two thirds of a transverse orbital dimension. The height was approximately one third of a vertical orbital dimension. SOOF was located in the inferolateral side of the orbit within a range between a medial +15 and a lateral −89 degrees to a vertical midpupillary line. The SOOF looks like a hockey stick head. The SOOF is divided into two parts, horizontal and vertical. The length of the SOOF horizontal part is almost equal to a transverse orbital dimension (a). The height of the SOOF vertical part was approximately three fourths (b × 3/4) of the vertical orbital dimension (b), and the width of vertical part was one fourth (a/4) of a transverse orbital dimension (a). Most of the SOOF vertical part was outside the lateral orbital rim, and the horizontal part was below the infraorbital rim. Histologically, ROOF and SOOF were situated deep to the orbicularis oculi muscle and superficial to the orbital septum and periosteum. ROOF and SOOF consisted more of fibrofatty tissue than the pure fatty nature of orbital fat. The findings in this study might be conducive to the practice of blepharoplasty and midface lift.

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 μm), and the thinnest skin is near the ciliary margin (A) (320 ± 49 μm). The upper tarsal area (C) and mid tarsal area (B) are 832 ± 213 and 703 ± 103 μm, 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.

Insertion of frontalis muscle relating to blepharoptosis repair.

The aim of the study is to elucidate the precise anatomy and histologic structure of frontalis muscle relating to blepharoptosis repair. Five Korean adult cadavers were used. The soft tissues of the lower forehead, including muscle and periosteum, were dissected at different sagittal planes and then observed histologically and photographed. Massons trichrome was used for staining the section specimens. The frontalis muscle passed through and inserted into the bundles of the orbicularis oculi muscle on the superior border of the eyebrow at middle and medial side of the upper eyelid. However, at the lateral side it inserted about 0.5 cm below the superior border of eyebrow. At the medial side of the eyelid, the most distal frontalis muscle was located deep to the procerus muscle and superficial to the corrugator muscle. A knowledge of the distal insertion of the frontalis muscle is referred to the muscle transfer procedure for blepharoptosis repair.

Anatomy of lower lacrimal canaliculus relative to epicanthoplasty.

The aim of this study is to elucidate detailed anatomy of the lower lacrimal canaliculus relative to epicanthoplasty. Nine lower eyelids of Korean adult cadavers were studied. Serial sagittal sections of the medial side of the lower eyelids including canaliculi were made, and the specimens were observed under a light microscope. The depth and width (diameter) of the vertical portion were 2.58 ± 0.24 mm and 0.44 ± 0.07 mm, respectively. A vertical portion of the canaliculus was about 1 mm (1.11 ± 0.16 mm) deep, and the horizontal portion was about 2 to 3 mm (2.08 ± 2.74 mm) long 2 mm below the mucocutaneous junction, where an incision may be given in epicanthoplasty. The lower lacrimal canaliculus is vulnerable to injury during epicanthoplasty.

Anatomic study of the lateral palpebral raphe and lateral palpebral ligament.

The aim of this study is to elucidate anatomic detail of the lateral canthal area relating to lateral canthoplasty. Thirty-three hemifaces of 22 Korean adult fresh cadavers were used. Thirty-one specimens were used for tension measurement and 2 for histologic study. There were 3 components of the lateral canthal area under the skin; lateral palpebral raphe (LPR), superficial lateral palpebral ligament (SLPL), and deep lateral palpebral ligament (DLPL). Lateral ends of superior and inferior orbicularis oculi muscles interlaced at the lateral commissure and formed LPR. SLPL extended from the lateral ends of tarsal plate to the periosteum of lateral orbital rim. Its transverse length was 9.4 ± 2.6 mm and vertical width was 3.6 ± 1.3 mm. DLPL extended from the lateral ends of tarsal plate deep to the origin of SLPL to Whitnalls tubercle on zygomatic bone inside the orbital margin. It is located deeper than SLPL. Its transverse length was 7.3 ± 1.6 mm and its vertical width was 9.0 ± 1.6 mm. Tensile strength of DLPL was 73.2 ± 26.8 N and stronger significantly than SLPL (30.0 ± 17.3 N). Tensile strength of LPR was 12.2 ± 8.0 N and weaker significantly than SLPL and DLPL. A detailed understanding of 3 layered structures (LPR, SLPL, and DLPL) at lateral canthal area is conducive to performing lateral canthoplasty.

Size of the superior palpebral involuntary muscle (Müller muscle).

The aim of this study was to elucidate the width and length of the superior palpebral muscle by using anti-&agr;-smooth muscle actin antibody. Ten orbits of 5 adult Korean cadavers were used. Eyelids were cut in vertical planes through midpupilliary, medial limbus, and lateral limbus and in horizontal planes at the anterior border of the superior transverse ligament and 2 mm proximal to the upper tarsal border. Superior palpebral muscle was localized using mouse monoclonal anti-&agr;-smooth muscle actin and counterstained with light green for collagen. In enlarged pictures of sections, widths, lengths, and thicknesses of the superior palpebral involuntary muscle were measured with a curved scale and were analyzed.The levator palpebrae superioris muscle was divided into superficial and deep parts below the superior transverse ligament. The levator aponeurosis originated from the superficial part and the superior palpebral muscle originated from the deep part of the levator palpebrae superioris muscle. The aponeurosis was inserted into the upper border of tarsus. The superior palpebral muscle fibers arose 2.71 ± 0.64 mm posterior to the anterior border of the superior transverse ligament. The superior palpebral muscle was trapezoidal. The lengths of its sides were 15.58 ± 1.82 and 22.30 ± 5.25 mm, and its height was 13.70 ± 2.74 mm. The levator aponeurosis covered the superior palpebral muscle anteriorly. The width of the levator aponeurosis was approximately 4 mm wider than the superior palpebral muscle. The thicknesses of the superior palpebral muscle were 0.14 ± 0.13 mm at the anterior border of the superior transverse ligament, 0.45 ± 0.11 mm at the superior fornix level, and 0.10 ± 0.03 mm at the upper border of the tarsal plate. One vascular layer was between the levator aponeurosis and the superior palpebral muscle (upper vascular layer), and the other was between the superior palpebral muscle and the conjunctiva (lower vascular layer). At the superior fornix level, thickness of the upper and lower vascular layers was 0.28 ± 0.06 and 0.38 ± 0.21 mm, respectively. The result of our study might contribute to corrective blepharoptosis surgery.

Musculature of the pars marginalis of the upper orbicularis oris muscle.

The aim of this study is to elucidate the muscular structure of the pars marginalis of the upper orbicularis oris muscle. Full-thickness upper lips of 11 Korean adult cadavers were used. Four sagittal sections were made and stained with trichrome. Throughout the vermilion zone of the upper lip, the pars marginalis is substantially anterior to the adjacent bundles of the pars peripheralis. The breadth was 1.3 to 2.5 mm above the vermillion border (2.5 ± 0.8 mm on the midline of philtrum, 1.3 ± 0.6 mm on the peak point of Cupids bow, 1.6 ± 0.5 mm at midlateral side, and 1.6 ± 0.4 mm at mouth corner). The lowest limit of the pars marginalis was located 2.5 to 3.1 mm below the vermillion border (3.1 ± 0.4 mm on the midline of philtrum, 3.0 ± 0.7 mm on the peak point of Cupids bow, 3.0 ± 0.7 mm at midlateral side, and 2.5 ± 0.7 mm at mouth corner). The thickness of the pars marginalis varied between 1.1 and 2.0 mm (2.0 ± 0.5 mm on midline of philtrum, 1.8 ± 0.5 mm on the peak point of Cupids bow, 1.9 ± 0.5 mm at midlateral side, and 1.1 ± 0.3 mm at mouth corner). An anatomic knowledge is conducive to precise repairs of the upper lip, particularly in cheiloplasty of congenital cleft lips.

Immunohistochemical study of differences between the muscle fiber types in the pars peripheralis and marginalis.

The aim of this study was to evaluate the immunohistochemical differences between the muscular fiber types in the pars peripheralis and pars marginalis of human orbicularis oris muscle. Five upper lips of fresh human adult cadavers were used. Full thickness of the upper lip, 5 mm in width, was harvested vertically at a peak point of cupids bow. Troponin I-SS and Troponin I-FS antibodies were used to determinate the slow and fast skeletal muscle fibers. The pars peripheralis is composed of slow fibers (22%) and fast fibers (73%). The pars marginalis is composed of slow fibers (30%) and fast fibers (66%). We assume that the pars peripheralis and pars marginalis should be repaired sortably because the muscle reaction and endurance are not the same.

Microscopic relation of palatopharyngeus with levator veli palatini and superior constrictor.

The aim of this study was to elucidate microscopic relation between the levator veli palatini, palatopharyngeus (PP), and superior constrictor (SC) muscle in transverse, parasagittal, and coronal sections. In 10 Korean adult cadavers, the entire soft palate was removed, trimmed, and preserved in 10% neutral buffered formalin. Specimens were embedded in paraffin and sectioned at a thickness of 10 &mgr;m. Blocks were cut the course of levator veli palatini. Also, transverse, parasagittal, and coronal section were made, stained using Masson trichrome, and observed under light microscope. Levator veli palatini was inserted between mucous gland anteriorly and musculus uvulae posteriorly in the midline of the soft palate, where they interdigitated with those in the contralateral side. Palatopharyngeus originated from the palatine aponeurosis and posterior mucosa of the soft palate. Most of the fibers of the PP did not cross the midline in their origin; however, some fibers interdigitated across the midline. As PP went downward and crossed the levator, it divided into anterior fasciculus and posterior fasciculus. Anterior fasciculus was thick and went downward along the anterolateral side of the levator. Posterior fasciculus was thin and widely spread along the posteromedial side of levator. Below the levator, 2 fasciculi united and were inserted to the medial side of SC. There were close attachment between the PP and SC. A detailed understanding of the microscopic relationship between the levator veli palatini, PP, and SC muscle is desirable for performing pharyngeal flap surgeries.

Cutaneous innervation of lower eyelid.

The loss of skin sensation or numbness after lower blepharoplasty is not uncommon. The aim of this study is to elucidate the infraorbital nerve (ION) and zygomaticofacial nerve (ZFN) in detail. Twenty-one hemifaces of 14 fresh Korean adult cadavers were dissected. Infraorbital nerve and ZFN came out of infraorbital foramen and zygomaticofacial foramen. They ran along superficial to the periosteum within and beneath the epimysium of the orbicularis oculi muscle and then through orbicularis oculi muscle perpendicularly and distributed to the skin. The distal branch approached to the lower border of the tarsal plate. Most terminal branches (93.8%) of ION were distributed medial to the lateral canthus. Only a few branches (6.2%) were lateral to the lateral canthus. Most (99.4%) terminal branches of ZFN were distributed lateral to the lateral canthus. Very few (0.6%) branches were medial to the lateral canthus. We conclude that the skin-muscle flap infringes less than the skin flap on the terminal branches of ION and ZFN in exposure of the orbital floor as well as in lower blepharoplasty.