Lower Nose Arterial Plexus and Implications for Safe Filler Injections.

BACKGROUND: The lower nose has abundant blood supply; however, nasal tip necrosis still occurs following filler injections. This study revealed the complicated pattern of the arterial supply of the lower nose. METHODS: The arterial pattern of the lower nose was studied in 40 cadavers using conventional dissections and translucent modified Sihler staining. RESULTS: Two arterial rings were connected in a figure of eight. The upper ring (nasal arterial circle) consisted of the lateral nasal and the subalar arteries encircling the nasal tip and alae. The lower ring (arterial plexus of the upper lip) was more important because of the contribution of the facial and superior labial arteries. This specific feature had not been mentioned elsewhere. CONCLUSION: Understanding this specific feature of the blood supply of the lower nose is essential for aesthetic physicians to perform the appropriate techniques during filler injection procedures in the nasal and perioral regions.

The Crest Injection Technique for Glabellar Line Correction and the Paracentral Artery.

The glabella is a zone that carries a high risk of blindness after performing filler injections. The arteries beneath the glabellar lines were investigated by meticulous dissections in 30 geriatric embalmed cadavers with latex injections into the arterial system. The results showed that the supratrochlear artery, a direct branch of the ophthalmic artery, ascended from the muscular layer of the medial eyebrow along the medial canthal vertical line of the intercanthal vertical zone (53 in 60 hemifaces, or 88%). The dominant single paracentral artery from the radix artery was found within the radix vertical zone (eight out of 30 glabellae, or 27%). Among these, the dominant paracentral artery was near the midline in two cadavers and arose along the radix vertical line in six cadavers. The dominant paracentral artery may be the cause of ocular complications during injections of glabellar lines between the medial eyebrows, especially at the radix vertical lines. The supratrochlear artery might cause ocular complications when an injection is performed close to the medial eyebrows. Pinching to create a skin crest and evert glabellar line for a precise injection is recommended to temporarily occlude the paracentral artery.

Anatomical Study of the Dorsal Nasal Artery to Prevent Visual Complications during Dorsal Nasal Augmentation.

Dorsal nasal augmentation is a common injection associated with ocular complications. Digital compressions on both sides of the nose are recommended during injection. Considering the reported incidences of visual complications, this preventive technique may need an adjustment for more effectiveness to prevent blindness. Therefore, the dorsal nasal arteries (DNAs) were studied by conventional dissections in the subcutaneous and fibromuscular tissues of the nasal dorsum in 60 embalmed cadavers. The results showed that among the 60 faces, 32 faces had bilateral DNAs (53.3%), 23 had dorsal nasal plexus with minute arteries (38.3%), and five had a single dominant DNA (8.3%). The DNA originated from one of the four arterial sources, which influenced the location and course of the artery. These sources included the ophthalmic angular arteries in 21 faces (56.8%), terminal ophthalmic arteries in two faces (5.4%), lateral nasal arteries in 11 faces (29.7%) and facial angular arteries in three faces (8.1%). Consequently, the dominant dorsal nasal artery running close to the midline found in 8% of the cases could make side compressions during nasal dorsum augmentation less effective from preventing ocular complications. However, an adjustment of digital compressions which combines pinching and side compressions is suggested to improve the safety.

A Cadaveric Study of Dye Spreading: Determining the Ideal Injection Pattern for Masseter Hypertrophy.

BACKGROUND: Masseter hypertrophy is the main cause of an asymmetrical and squared lower facial contour in the Asian community. Botulinum toxin injection technique is crucial to treat this condition. OBJECTIVE: To improve injection techniques for masseter hypertrophy by elucidating the distribution of the injections within the masseter. METHODS: Thirty masseter muscles were divided into 6 groups of 5 muscles each. Each group received one 0.2- or 0.3-mL injection at Point A, B, or C according to a three-point technique. Muscle dimensions and dye of the primary and secondary dye spreading were measured. RESULTS: The average muscle length, width, and thickness were 69.87, 33.50, and 11.23 mm, respectively. The average primary longitudinal and horizontal spreading was 36.56 and 15.60 mm, respectively. No statistically significant difference was found between 0.2- and 0.3-mL injections at each point. CONCLUSION: The three-point technique best fits in the safe zone and should be the standard injection technique for masseter hypertrophy. Injection at Points B and C may create secondary spreading that affect the risorius muscle and the parotid gland which are the cause of asymmetrical smiling and xerostomia, respectively. The dosage should be adjusted according to the muscle volume and not only the thickness.

Achieving the Most Effective Hanging Points at the Lower End of the Face for Thread Lifting: Quantitative Measurement of Tissue Resistance in Different Facial Layers.

The thread lift procedure is a minimally invasive alternative to facelift surgery. The hanging point, which the terminal end of the thread is hooked into, is an important component. If it is loose and cannot stabilize the passage when the inserted thread is pulled, the lifting effect will fail. Therefore, the aim of this study was to elucidate the ability of the tissue to support the thread attachment in the different facial layers while performing this procedure. Twenty hemi-faces of 10 soft cadavers, which were divided into 45 blocks, were used to measure the tissue resistance in the midface area. The resistance of the soft tissue in the four facial layers in each block was measured while a 22G cannula connected with a force gauge was passed through it. The results showed that the tissue resistance in the sub-SMAS was higher than the SMAS and subcutaneous layers in the blocks located in the nasolabial and perioral regions. This was also significantly greater than the resistance in the subcutaneous layer in the three medial blocks below the oral commissure (P < 0.05). However, the low resistance of the sub-SMAS was found in the blocks located in the buccal and lower parotidomasseteric regions. Thus, it was preferable that the hanging point was based in the deep plane (sub-SMAS and SMAS layers) of the nasolabial, perioral, and upper parotidomasseteric regions. Moreover, the sub-SMAS layer within the buccal and lower parotidomasseteric regions should be avoided due to the loose attachment in the buccal capsule and subplatysmal fat.

The analgesic efficacy of anterior femoral cutaneous nerve block in combination with femoral triangle block in total knee arthroplasty: a randomized controlled trial.

BACKGROUND: Ultrasound-guided femoral triangle block (FTB) can provide motor-sparing anterior knee analgesia. However, it may not completely anesthetize the anterior femoral cutaneous nerve (AFCN). We hypothesized that an AFCN block (AFCNB) in combination with an FTB would decrease pain during movement in the immediate 12 h postoperative period compared with an FTB alone. METHODS: Eighty patients scheduled to undergo total knee arthroplasty were randomized to receive either FTB alone (FTB group) or AFCNB with FTB (AFCNB + FTB group) as part of the multimodal analgesic regimen. The primary outcome was pain during movement at 12 h postoperatively. Secondary outcomes included numeric rating scale (NRS) pain scores, incidence of surgical incision site pain, intravenous morphine consumption, immediate functional performance, patient satisfaction, and length of hospital stay. RESULTS: The NRS pain scores on movement 12 h postoperatively were significantly lower in the AFCNB + FTB group than in the FTB group (mean difference: -2.02, 95% CI: -3.14, -0.89, P < 0.001). The incidence of pain at the surgical incision site at 24 h postoperatively and morphine consumption within 48 h postoperatively were significantly lower (P < 0.001), and quadriceps muscle strength at 0° immediately after surgery was significantly greater in the AFCNB + FTB group (P = 0.04). CONCLUSIONS: The addition of ultrasound-guided AFCNB to FTB provided more effective analgesia and decreased opioid requirement compared to FTB alone after total knee arthroplasty and may enhance immediate functional performance on the day of surgery.

Three-Dimensional Evaluation of the Depressor Anguli Oris and Depressor Labii Inferioris for Botulinum Toxin Injections.

BACKGROUND: Botulinum toxin type A (BoNT-A) injection administered at an inappropriate site or depth can produce an unwanted change in facial animation because the depressor anguli oris (DAO) and depressor labii inferioris (DLI) muscles are partially overlapped. Therefore, simple BoNT-A injection guidelines, based on 3-dimensional (3D) facial anatomic references and landmarks, would be very useful. OBJECTIVES: The aim of this study was to establish novel BoNT-A injection guidelines that include the soft tissue thickness at the lower perioral region. Data were acquired with a 3D scanning system combined with dissections in order to obtain accurate injection sites and depths for the DAO and DLI. METHODS: 3D scans of the facial skin, superficial fat, and facial muscle surface were performed in 45 embalmed cadavers. The thicknesses of the skin and subcutaneous layer were calculated automatically from superimposed images at each of 5 reference points (P) in the perioral region. RESULTS: In every case (100%), P3 and P5 were located in the DLI and DAO areas, respectively (45/45). Therefore, we defined P3 as the "DLI point" and P5 as the "DAO point." The soft tissue thicknesses at the DLI and DAO points were 6.4 [1.7] mm and 6.7 [1.8] mm, respectively. CONCLUSIONS: The P3 and P5 described in this study are effective guidelines that only target the DLI and DAO. Clinicians, specifically, can easily use facial landmarks, such as the cheilion and pupil, to assign the DLI and DAO points without any measurement or palpation of the modiolus.

Cadaveric Dissections to Determine Surface Landmarks Locating the Facial Artery for Filler Injections.

BACKGROUND: The facial artery is a high-risk structure when performing filler injections at the nasolabial fold, buccal, and mandibular regions. OBJECTIVES: This study aimed to establish reference landmarks locating the course of the facial artery and its essential branches. METHODS: Thirty-one embalmed cadavers were enrolled in this study. The course of the facial artery was observed in regard to the following reference points: masseter insertion, oral commissure, and common bony landmarks. The corner of the mouth was utilized as the landmark to measure the turning point of the facial artery. RESULTS: Seven points were established to identify the course and turning point of the facial artery. These included the anterior masseteric, lateral mental, infraorbital, medial canthal, basal alar, post-modiolar (PMP), and supra-commissural (SCP) points. The course of the facial artery deviates at least twice at the lateral mental points and at the SCP or PMP. The facial artery appeared more medially when the artery turned at the PMP and SCP. It presented through the lateral channel if the turning point was solely at the PMP. Wherever the facial artery deviates, it can be divided into 3 segments: the mandibular, buccal, and nasolabial segments. The arterial course may deviate laterally from the mouth corner towards PMP. The nasolabial segment may also deviate laterally to the basal alar point at the alar grove for 0.5 to 1 cm. CONCLUSIONS: The deviation of facial artery closely relates with mandibular, buccal, and nasolabial segments. It is essential in avoiding arterial injury for physicians and surgeons who perform procedures in these areas.

Localization and Topography of the Arteries on the Middle Forehead Region for Eluding Complications Following Forehead Augmentation: Conventional Cadaveric Dissection and Ultrasonography Investigation.

Forehead augmentation with filler injection is one of the most dangerous procedures associated with iatrogenic intravascular injection resulting in the severe complications. Nonetheless, few studies have determined the explicit arterial localization and topography related to the facial soft tissues and landmarks. Therefore, this study aimed to determine an arterial distribution and topography on the middle forehead region correlated with facial landmarks to grant an appropriate guideline for enhancing the safety of injection. Nineteen Thai embalmed cadavers were discovered with conventional dissection and 14 Thai healthy volunteers were investigated with ultrasonographic examination on the middle forehead. This study found that at the level of mid-frontal depression point, the transverse distance from the medial canthal vertical line to the superficial and deep branches of supraorbital artery were 9.1 mm and 15.1 mm, respectively. Whereas the depths from the skin of these arteries were 4.1 mm and 4.3 mm, respectively. Furthermore, the frontal branch of superficial temporal artery was detectable in 42.1% as an artery entering the forehead area. At the level of lateral canthal vertical line, the vertical distance of frontal branch was 31.6 mm, and the depth from skin of the artery was 2.7 mm. In conclusion, a proper injection technique could be performed based on an intensive arterial distribution and topography, and ultrasonographic examination before the injection is also suggested in order to restrict the opportunity of severe complications.

Implication of Location of the Ascending Mental Artery at the Chin Injection Point.

BACKGROUND: Facial proportions can be improved by means of chin augmentation in patients with a receding chin. The ascending mental artery is the main arterial supply to the top of the chin, and arterial occlusion of this artery can result in soft-tissue infarction. This study aims to measure the topographic anatomy of the ascending mental artery at the chin injection area, using a three-dimensional camera. METHODS: Thirty-one embalmed cadaveric faces were dissected at the chin. The midline of the inferior margin of the mandibular protuberance was marked with a pin. A variation in size between the two opposite ascending mental arteries was noticed. The depth of the artery from the skin surface and distance from the midline were measured using a three-dimensional camera. RESULTS: There were 19 dominant ascending mental arteries on the right and 12 on the left. The dominant ascending mental arteries enter the chin paracentrally, approximately 6 mm (mean ± SD, 5.64 ± 4.34 mm) from the midline, within the muscular plane, and at a depth of 4.15 ± 1.95 mm from the skin. Furthermore, the artery formed an anastomosis with the sublingual artery, within the floor of the mouth. CONCLUSION: Every aesthetic physician should recognize the course of the ascending mental artery and use the appropriate techniques to avoid vascular injury during chin augmentation using filler injections.

A novel anatomical consideration on the exposed segment of the facial artery.

An understanding of the location and depth of the facial artery (FA) is essential in aesthetic surgery and various cosmetic procedures. The purpose of this study was to clarify the three-dimensional (3D) topography of the exposed segment (ES) of the FA and to provide information to help minimize complications during clinical procedures. From 50 embalmed adult cadavers, the undissected and dissected hemifaces were scanned and reconstructed using the 3D scanner. Then the topographic location of the ES was identified and measured from the superimposed the 3D images. The ES was observed in 82% of the whole specimens. The exposure patterns of the ES were examined, and classified into three types: Type I, one site exposed pattern (74%); Type II, two sites exposed pattern (8%); and Type III, nonexposed pattern (18%). The extent of the ES was located at 2.2 mm above and 4.2 mm below the cheilion (Ch)-otobasion inferius line, and 20.0 to 25.2 mm from the Ch on the lateral aspect. In the frontal view, the average distance from the mid-pupillary line to the ES was 7.1 mm, and from the lateral canthal line to the ES was 6.1 mm. The ES was 7.6 mm below the skin surface. The results of this study will help to provide safe guidelines for filler injections as well as selecting the safe regions in various clinical procedures. Clin. Anat. 33:257-264, 2020. © 2019 Wiley Periodicals, Inc.

Ethnic differences in platysmal perforators and its relevance for the platysma myocutaneous flap.

BACKGROUND: Variable flap loss rates for the platysma myocutaneous flap have been reported for the Caucasian and the Asian population, which are 10.1% and 1.6%, respectively. This study was designed to investigate ethnic differences in the number and location of platysmal perforators that influence flap survival rates. METHODS: The number and location of platysmal perforators were investigated in a total of 60 platysma muscles: bilaterally in 20 Caucasian (13 males and 7 females) and 10 Asian (5 males and 5 females) specimens using cadaveric dissections. Adjustment for inter-individual variability in platysma length and width was performed by standardizing each x-value to mandibular length and each y-value to mandibulo-clavicular distance. RESULTS: A total of 64% of all detected platysmal perforators were found in the medial half of the muscle following the pathway of the external carotid artery. Individuals of Caucasian ethnicity had a mean number of 7.60 ± 2.0 perforators per side, whereas individuals of Asian ethnicity had a mean number of 13.05 ± 1.76 perforators per side (p < 0.001). Individuals of Asian ethnicity had a statistically significant increased number of platysmal perforators in the medial middle (2.95 ± 1.05 vs. 1.60 ± 1.08; p < 0.001) and lower (1.60 ± 1.35 vs. 0.73 ± 0.85; p = 0.003) regions of the platysma compared to those of Caucasian individuals. CONCLUSION: A significantly higher number of platysmal perforators were identified in the investigated Asian population. This provides a potential explanatory model for the reported lower platysma myocutaneous flap loss rates in the Asian population than in the Caucasian population.

Translucent and Ultrasonographic Studies of the Inferior Labial Artery for Improvement of Filler Injection Techniques.

Lower lip augmentation by filler injection is an aesthetic procedure essential for achieving a feminine look and to enhance attractiveness. Complications as a result of injury to the inferior labial artery can result in undesirable outcomes. METHODS: The translucent technique was used to study the origin of the inferior labial artery in 11 cadavers. Ultrasonography of the inferior labial artery was also performed in 20 volunteers, which provided supplemental data to this study, in relation to establishing recommendations for filler injection. RESULTS: Five different types of inferior labial artery were described. These types were found in various combination patterns. Types 2, 4, and 5 are more vulnerable to arterial injury during filler injection. Ultrasonography revealed a depth of 6 mm and an arterial position at the vermillion border as the dangerous injection plane. CONCLUSION: The origins and courses of the inferior labial artery are classified into 5 types. These types are often found in combination with each other in different faces, resulting in large anatomical variation between people. Types of combination influence severity of lower lip necrosis when arterial injury occurs. The physician should be aware of these anatomical variations during aesthetic treatments and reconstructive procedures to avoid the dangers of accidental arterial injury.

Locational Relationship between the Lateral Border of the Frontalis Muscle and the Superior Temporal Line.

BACKGROUND: The frontalis is a representative target muscle for botulinum neurotoxin type A injections aimed at treating horizontal wrinkles in the forehead region. However, a lack of information regarding the shape and thickness of the frontalis may lead to unexpected side effects. METHODS: This study dissected hemifaces of 44 embalmed Korean and Thai cadavers and performed ultrasound examinations on 20 Korean volunteers. Two anatomical types were identified: (1) the lateral portion of the frontalis covered the superior temporal line in type I, and (2) the lateral border of the frontalis and the superior temporal line almost coincided in type II. A horizontal line was drawn laterally from the midpoint between the metopion and the glabella, and landmarks F1, F2, and F3 were defined as points where this horizontal reference line intersected with vertical lines from the midpoint of the pupil, the lateral canthus, and the lateral orbital rim, respectively. RESULTS: Type I was more common than type II [84 percent (37 of 44) versus 16 percent (seven of 44)]. When the lateral border of the frontalis ran along the border, there were no cases in which the superior temporal line was not visible. The mean minimum distance in type I was 10.53 mm. The muscle thicknesses at F1, F2, and F3 were 1.80 ± 0.44 mm (mean ± SD), 1.61 ± 0.37 mm, and 0.11 ± 0.04 mm, respectively. CONCLUSIONS: This study yielded data on the location and thickness of the lateral border of the frontalis. An anatomical study-based, ultrasound-guided injection technique can achieve reliable results when noninvasive treatment is applied to the forehead area.

Three-Dimensional Topography of the Emerging Point of the Ophthalmic Artery.

BACKGROUND: During periorbital noninvasive and surgical procedures, there is the risk of iatrogenic injury to the emerging point of the ophthalmic artery. This study aimed to determine the three-dimensional location of the emerging point of the ophthalmic artery and to provide clinicians with anatomical information that would help them to avoid associated complications. METHODS: Seventeen hemifaces of the emerging point of the ophthalmic artery from 10 Korean and seven Thai cadavers were dissected and scanned by a three-dimensional scanner. The emerging points of the ophthalmic artery of 30 healthy Korean volunteers were also detected using an ultrasound imaging system. RESULTS: The transverse distance from the medial canthus to the emerging of the ophthalmic artery was 3.8 ± 1.0 mm medially, and the vertical distance was 14.0 ± 2.9 mm superiorly. The transverse distance from the midline was 16.5 ± 1.7 mm to the emerging point of the ophthalmic artery and 20.0 ± 2.0 mm to the medial canthus. The measured depth from the skin surface to the emerging point of the ophthalmic artery was 4.8 ± 1.7 mm by means of three-dimensional scanning and 4.5 ± 1.1 mm using ultrasound detection. The vertical distance from the inferior margin of the superior orbital rim to the emerging point of the ophthalmic artery was 5.3 ± 1.4 mm. CONCLUSION: These data inform clinicians about the anatomical three-dimensional location of the emerging point of the ophthalmic artery, which will help them to avoid iatrogenic injury when they are performing periorbital clinical procedures.