You-Jin Choi

New Anatomical Insights on the Course and Branching Patterns of the Facial Artery: Clinical Implications of Injectable Treatments to the Nasolabial Fold and Nasojugal Groove

Background: Improper manipulation of injectable treatments to the face can result in disastrous vascular complications. The aim of the present study was to elucidate the detoured course of the facial artery and to provide detailed metric data regarding facial artery location with a view to helping physicians avoid iatrogenic vascular accidents during injectable treatments. Methods: Sixty specimens from 35 embalmed cadavers (24 male and 11 female cadavers; mean age, 70.0 years) and one fresh male cadaver (age, 62 years) were used for this study. Results: In 56 cases (93.3 percent), the branches of the facial artery were observed at the vicinity of the nasolabial fold. The facial artery was located 3.2 ± 4.5 mm (mean ± SD) lateral to the ala of the nose and 13.5 ± 5.4 mm lateral to the oral commissure. It crossed the nasolabial fold in 33.9 percent of cases, and ascended within 5 mm of the nasolabial fold in 42.9 percent. The facial artery and detoured branches were found in 18 cases (30.0 percent). In the cases with detoured branches, the facial artery turned medially over the infraorbital area at 39.2 ± 5.8 mm lateral to the facial midsagittal line and 35.2 ± 8.2 mm inferior to the plane connecting the medial epicanthi of both sides. The nasojugal portion of the detoured branch traveled along the inferior border of the orbicularis oculi and then ascended toward the forehead, forming the angular artery. Conclusion: This detailed vascular anatomy of the facial artery will promote safe clinical manipulations during injectable treatments to the nasolabial fold and nasojugal groove.

Topographic anatomy of the superior labial artery for dermal filler injection.

Background: The superior labial artery, which is a branch of the facial artery, supplies the upper lip area. The aim of this study was to determine the distribution pattern of the superior labial artery and provide precise topographic information of the artery for dermal filler injection. Methods: Sixty hemifaces from 18 Korean and 18 Thai cadavers were used for this study. The various distribution patterns of the superior labial artery were classified according to its relationship with the facial artery. Results: The course of the superior labial artery was classified into four types: type I (56.7 percent), in which the artery and the alar branch both arise directly and independently from the facial artery; type II (21.7 percent), in which the superior labial artery branches off from the facial artery and then gives off an alar branch; type III (15.0 percent), in which it is the terminal branch of the facial artery; and type IV (6.7 percent), in which the artery is absent. The origin of the superior labial artery was located 12.1 ± 3.1 mm (mean ± SD) lateral and at a variable angle of 42.8 ± 26.9 degrees relative to the mouth corner. Conclusions: The superior labial artery proceeded from the origin of the artery located within a 1.5-cm-side square superolateral to the mouth corner as running along the vermilion border of the upper lip to the facial sagittal midline at a depth of 3 mm. Thus, clinicians should be careful when injecting dermal filler into this area.

Facial arterial depth and relationship with the facial musculature layer.

Background: Previous studies have revealed a variation in the origin and distribution patterns of the facial artery. However, the relationship between the facial artery and the facial muscles has not been well described. The purpose of this study was to determine the facial artery depth and relationship with the facial musculature layer, which represents critical information for dermal filler injection and oral and maxillofacial surgery. Methods: Fifty-four embalmed adult faces from Korean cadavers (36 male and 18 female cadavers; mean age, 73.3 years) were used in this study. A detailed dissection was performed, with great care being taken to avoid damaging the facial artery underlying the facial skin and muscle. Results: The facial artery was first categorized according to the patterns of its final arterial branches. The branching pattern was classified simply into three types: type I, nasolabial pattern (51.8 percent); type II, nasolabial pattern with an infraorbital trunk (29.6 percent); and type III, forehead pattern (18.6 percent). Each type was further subdivided according to the facial artery depth and relationship with the facial musculature layer as types Ia (37.0 percent), Ib (14.8 percent), IIa (16.7 percent), IIb (12.9 percent), IIIa (16.7 percent), and IIIb (1.9 percent). Conclusion: This study provides new anatomical insight into the relationships between the facial artery branches and the facial muscles, including providing useful information for clinical applications in the fields of oral and maxillofacial surgery.

Intramuscular innervation patterns of the brachialis muscle.

The aim of this study was to provide accurate anatomical descriptions of the patterns of innervation of the brachialis muscle by the musculocutaneous, radial, and median nerves. Sihlers staining method was applied to 20 brachialis muscles from 10 cadavers to reveal the intramuscular distribution patterns of the musculocutaneous, radial, and median nerves. Three patterns of innervation of the brachialis muscle by the three studied nerves were found: single, double, and triple. These innervation patterns were categorized into four types: Type I—only the musculocutaneous nerve; Type II—double innervation by the musculocutaneous and radial nerves; Type III—double innervation by the musculocutaneous and median nerves; and Type IV—triple innervation by all three nerves. Single, double, and triple innervation patterns occurred 25%, 70% (Type II, 55%; Type III, 15%), and 5% of the samples, respectively. The brachialis muscle is not solely innervated by the musculocutaneous nerve but also by the radial and median nerves, thus making it a potentially triply innervated muscle. Double innervation of this muscle with either the musculocutaneous and median nerve or the musculocutaneous and radial nerves was also observed. Clin. Anat. 28:123–127, 2015.

Characterizing the Lateral Border of the Frontalis for Safe and Effective Injection of Botulinum Toxin.

BACKGROUND The forehead is a common site for injection of botulinum neurotoxin type A (BoNT-A) to treat hyperactive facial muscles. Unexpected side effects of BoNT-A injection may occur because the anatomy of the forehead musculature is not fully characterized. OBJECTIVES The authors described the lateral border of the frontalis in terms of facial landmarks and reference lines to determine the safest and most effective forehead injection sites for BoNT-A. METHODS The hemifaces of 49 embalmed adult Korean cadavers were dissected in a morphometric analysis of the frontalis. L2 was defined in terms of FT (the most protruding point of the frontotemporal region), L0 (the line connecting the infraorbital margin with the tragus), and L1 (the line parallel to L0 and passing through FT) such that L2 was positioned 45° from L1 and passed through FT. RESULTS The distance from FT to the superior margin of the orbicularis oculi was 12.3 ± 3.3 mm. The frontalis extended more than 5 cm along L2 in 49 of 49 cases (100%), more than 6 cm in 47 cases (95.9%), more than 7 cm in 34 cases (69.4%), more than 8 cm in 11 cases (22.4%), and more than 9 cm in 3 cases (6.1%). The lateral border of the frontalis ran parallel to and within 1 cm of the medial side of L2. CONCLUSIONS Surface anatomy mapping can assist with predicting the lateral border of the frontalis to minimize the side effects and maximize the efficiency of BoNT-A injections into the forehead.

Quantitative anatomical analysis of facial expression using a 3D motion capture system: Application to cosmetic surgery and facial recognition technology.

The topography of the facial muscles differs between males and females and among individuals of the same gender. To explain the unique expressions that people can make, it is important to define the shapes of the muscle, their associations with the skin, and their relative functions. Three‐dimensional (3D) motion‐capture analysis, often used to study facial expression, was used in this study to identify characteristic skin movements in males and females when they made six representative basic expressions. The movements of 44 reflective markers (RMs) positioned on anatomical landmarks were measured. Their mean displacement was large in males [ranging from 14.31 mm (fear) to 41.15 mm (anger)], and 3.35–4.76 mm smaller in females [ranging from 9.55 mm (fear) to 37.80 mm (anger)]. The percentages of RMs involved in the ten highest mean maximum displacement values in making at least one expression were 47.6% in males and 61.9% in females. The movements of the RMs were larger in males than females but were more limited. Expanding our understanding of facial expression requires morphological studies of facial muscles and studies of related complex functionality. Conducting these together with quantitative analyses, as in the present study, will yield data valuable for medicine, dentistry, and engineering, for example, for surgical operations on facial regions, software for predicting changes in facial features and expressions after corrective surgery, and the development of face‐mimicking robots. Clin. Anat. 28:735–744, 2015.

Anatomical analysis of the distribution patterns of occipital cutaneous nerves and the clinical implications for pain management

Purpose Establishing the distribution patterns of occipital cutaneous nerves may help us understand their contribution to various occipital pain patterns and ensure that a proper local injection method for treatment is employed. The aim of this study was to demonstrate the detailed distribution patterns of the greater occipital nerve (GON), lesser occipital nerve (LON), and third occipital nerve (TON) using the modified Sihler’s staining technique. Methods Ten human cadavers were manually dissected to determine the nerve distributions. Specimens from eight human cadavers were treated using the modified Sihler’s staining. Results In all cases, distinct GON branches proceeded laterally and were intensively distributed in the superolateral area from their emerging point. Very thin twigs were observed at the middle-trisected area, which had a fan-like shape, in the middle-upper occipital region. Conclusion The LON and TON distribution areas were biased to the lateral side below the superior nuchal line, although these nerves exhibited multiple interconnections or overlapping areas with the GON. Furthermore, a nerve rarified zone in the shape of an inverted triangle was identified in the middle occipital area. Our findings improve our understanding of the occipital nerve anatomy and will aid in the management of occipital pain in clinical practice.

Intramuscular innervation of the subscapularis muscle and its clinical implication for the BoNT injection: An anatomical study using the modified Sihler's staining: Subscapularis muscle innervation

Shoulder pain is commonly associated with spasticity of the rotator cuff muscles including the subscapularis (SSC). The aim of this study was to elucidate the intramuscular innervation pattern of the SSC using the modified Sihlers staining technique to facilitate the targeting of botulinum neurotoxin (BoNT) injections to alleviate shoulder spasticity. Ten SSC specimens (mean age, 81.5 years) were used in this study. Modified Sihlers staining was used to clarify the muscle and to stain the intramuscular nerves. Their extramuscular and intramuscular innervation patterns were examined. The upper subscapular, lower subscapular, thoracodorsal, and axillary nerves (USN, LSN, TDN, and AXN) innervated the SSC in 100%, 80%, 20%, and 40% of specimens, respectively. There was an anastomosis between the USN and LSN in the central portion of the SSC in more than half of the cases. The USN innervated the overall portion of the muscle. In contrast, the additional branches from the TDN and AXN innervated the inferior SSC portion. The superficial branches of the USN were mostly distributed in the superior SSC portion while the deep branches were distributed in the inferior portion. As a major intramuscular nerve within the SSC, the USN should be targeted by a BoNT injection. Regarding the USN distribution, the aim should be to spread the BoNT injectate within the central SSC portion. For supplementary injection to the AXN, the lateral approach would be more appropriate than alternatives. A physician performing a BoNT injection should consider the intramuscular innervation of the SSC portion. Clin. Anat. 32:110–116, 2019.

Anatomic Study of the Dorsalis Pedis Artery, First Metatarsal Artery, and Second Metatarsal Bone for Mandibular Reconstruction

PURPOSE The purpose of this study was to clarify the anatomic variation of the dorsalis pedis and first metatarsal arteries and to define the trabecular-to-cortical bone ratio (TBR) of the second metatarsal bone to ascertain their suitability as implants. MATERIALS AND METHODS Fifty-two specimens were prepared for this study. Each specimen was dissected on the dorsal side of the foot to search for the dorsalis pedis artery. RESULTS Three types of dorsalis pedis artery were found: in type A, which was the most common, the artery continuously formed the first metatarsal artery; in type C, which was the second most common, the artery coursed below the first dorsal interosseous muscle; and in type B, the artery coursed from the lateral side. Five variations of the first metatarsal artery were identified: the most common was type IIb, in which the artery coursed below the first dorsal interosseous muscle; followed by type Ib, in which the artery coursed obliquely through the muscle; type Ic, in which the artery coursed parallel to the muscle; type IIa, in which the artery coursed above and below the muscle; and type Ia, in which the artery coursed only above the muscle. The second metatarsal bone was divided into 5 regions. There was no trabecular bone in regions 1 and 5. The TBR appeared to be lower in region 3 than in regions 2 and 4 and highest in region 2. CONCLUSION All regions of the second metatarsal bone appear to be suitable as implants, but when placing the implant in the proximal end, care should be taken not to overheat the bone and to be wary of perforation when placing it on the middle side.

Follicular fluid PGF2α and IL-1β levels according to the presence of oocyte retrieved in IVF-ET patients

목적: Follicular development is fundamental to successful outcome in IVF cycle, which is a complex process regulated by numerous factors. Follicular fluid (FF) contains several substances, such as cytokines, growth factors, and hormones, which may affect on developmental oocyte competence. LH surge stimulate prostaglandin biosynthesis by ovarian follicles as a results of induction of COX-2 enzyme in the preovulatory granulosa cells, which is associated with cumulus expansion and ovulation. Although about 90% of MII oocytes are obtained from follicles ≥ 14mm on the day of oocytes retrieval, the follicles from which an oocyte was not retrieved may have no oocyte for real or may have not been detached from follicular wall due to the poor expansion of cumulus. The aim of this study was to compare follicular fluid PGF2α and IL-1β levels according to the presence of oocyte retrieved. 방법: 80 FF samples were collected from infertile patients undergoing controlled ovarian stimulation for IVF-ET. Study subjects were divided into two groups according to the presence of oocyte: group with oocyte retrieved (group A, n=32) vs. group without oocyte retrieved (group B, n=48). FF from dominant follicles were obtained during oocyte retrieval and stored at -70 °C. FF IL-1β and PGF2α levels were measured by enzyme-linked immunosorbent assay and compared between the two groups, and statistically analyzed using non-parametric methods. 결과: There were no significant differences in clinical characteristics such as age, BMI, duration of infertility, number of previous attempts, basal serum FSH levels and antral follicle counts between the two groups. There were no significant differences in COH and IVF outcomes including total dose of gonadotropin used, duration of ovarian stimulation, serum E2 levels on the day of hCG, number of oocytes retrieved, fertilization rate, number of embryos transferred, cumulative embryo scores and pregnancy rate between the two groups. FF PGF2α levels were significantly higher in the group with oocyte retrived compared to the group without oocyte retrieved. 결론: The dominant follicle from which an oocyte was not retrieved may have lower FF PGF2α levels. The PGF2α levels could be used as a predictive marker in assisted reproductive technology.