Positional relationship of superior and inferior labial artery by ultrasonography image analysis for safe lip augmentation procedures

Three-Dimensional Computed Tomography Scanning Study of the Superior Labial Artery in Chinese Individuals for Assessing Filler Injection Safety

BACKGROUND

Lip filler injection is one of the most common minimally invasive cosmetic procedures involving the face; however, vascular complications are not uncommon. The aim of this study was to investigate the anatomy of the superior labial artery (SLA) and provide precise topographic information for dermal filler injection into the lips.

METHODS

Computed tomography (CT) scans of 52 cadaveric heads injected with lead oxide were obtained. We then used Mimics software to construct 3D images of the SLA described by a coordinate system based on the bilateral external auditory canal and the left orbit. This study aimed to classify the SLA in the Han Chinese population, measure its diameter at specific points, and determine the thickness of the lip at those points. Ultimately, we utilized a thermal imaging technique to illustrate the course and depth of the SLA within the lip. The objective of this study was to provide safe guidance for clinical injections.

RESULTS

In this study, the SLA was successfully identified in all cadavers. The mean overall diameter of the superior labial arteries was 1.36 ± 0.28 mm. The superior labial artery showed a general course from deep to shallow with an average depth of 5.68 ± 1.68 mm from the oral commissure to the midline.

CONCLUSIONS

There are anatomical differences in the superior labial arteries among Chinese people. Furthermore, 3D CT images can digitally elucidate the exact positions of the superior labial artery via a coordinate system, improving the safety of upper lip filler injections in clinical settings.

LEVEL OF EVIDENCE IV

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Increasing precision during neuromodulator injections for frontal rhytids-Using ultrasound imaging to identify the line of convergence

BACKGROUND

Recent research introduced the concept of the "line of convergence" as a guide for injectors to enhance precision and avoid complications when treating the frontalis muscle with toxins. However, currently, no pre-injection ultrasound scanning is employed to increase precision and reduce adverse events when searching for the line of convergence.

OBJECTIVE

To explore the feasibility and practicality of implementing pre-injection ultrasound scanning into aesthetic neuromodulator treatments of the forehead.

METHODS

The sample of this study consisted of n = 55 volunteers (42 females and 13 males), with a mean age of 42.24 (10.3) years and a mean BMI of 25.07 (4.0) kg/m2. High-frequency ultrasound imaging was utilized to measure the thickness, length, and contractility of the frontal soft tissue and to determine the precise location of the line of convergence during maximal frontalis muscle contraction.

RESULTS

The results revealed that the line of convergence was located at 58.43% (8.7) of the total forehead height above the superior border of the eyebrow cilia without a statistically significant difference between sex, age, or BMI. With frontalis muscle contraction, the forehead shortens in males by 25.90% (6.5), whereas in females it shortens only by 21.74% (5.1), with p < 0.001 for sex differences.

CONCLUSION

This study demonstrated the feasibility and practicality of pre-injection ultrasound scanning for facial aesthetic neuromodulator treatments. Knowing the location of the line of convergence, injectors can determine precisely and on an individual basis where to administer the neuromodulator deep or superficial or when the injection location is at risk to cause eyebrow ptosis.

Intralabial Lip Compartments and Their Potential Clinical Relevance

BACKGROUND

Aesthetic soft-tissue filler injections for lip enhancement are popular and performed throughout the world. When injecting lips with a cannula, as the cannula is advanced, resistance is perceived in consistent locations, potentially indicating boundaries between intralabial compartments.

OBJECTIVE

We aimed to investigate whether intralabial compartments exist and, if so, to describe their volumes, location, boundaries, and dimensions.

METHODS

This cadaveric study investigated a total of 20 human body donors (13 male, seven female) with a mean (SD) age at death of 61.9 years (23.9) and body mass index of 24.3 kg/m 2 (3.7). The investigated cohort included 11 White donors, eight Asian donors, and one Black donor. Dye injections simulating minimally invasive lip treatments were conducted.

RESULTS

Independent of sex or race, six anterior and six posterior compartments in the upper and lower lip were identified, for a total of 24 lip compartments. Compartment boundaries were formed by vertically oriented septations that were found in consistent locations. The anterior compartments had volumes ranging from 0.30 to 0.39 cc; the posterior compartment volume ranged from 0.44 to 0.52 cc. The compartment volumes were larger centrally and decreased gradually toward the oral commissure.

CONCLUSIONS

The volume and size of each of 24 compartments contribute to the overall appearance and shape of the lips. To achieve a natural lip shape preserving aesthetic outcome it may be preferable to administer the volumizing product using a compartment-respecting injection approach.

A Natural Flat Volumized Lips Filler Technique: Retrospective Analysis of 920 Patients

BACKGROUND

Traditionally, hyaluronidase (HYAL) is used after hyaluronic acid (HA) injection to dissolve the undesired migration of product.

OBJECTIVE

To describe a novel lip augmentation technique that uses HA and HYAL simultaneously in patients who previously had HA migration.

METHODS AND MATERIALS

Nine hundred twenty female patients were included. In the first group ( n = 793), HA injections were performed in subcutaneous plane of the lips. In the second group who had previous product migration ( n = 127), 7.5 units of HYAL is injected in 4 points in ergotrid area before proceeding with HA injection.

RESULTS

The medicis lip fullness scale scores after 2 weeks improved in all patients, while 92% of patients perceived the results as "very much improved" with Global Aesthetic Improvement Scale ( p ˂ .001). There was no difference between 2 groups regarding the patient satisfaction rates ( p ˃.05), while filler migration was seen in 0.2% ( n : 15) of patients in the first group during the follow-up period.

CONCLUSION

The new vertical injection approach provided an increased vertical height, optimal eversion, and an incisor display on the lips. The simultaneous use of HYAL before HA injection seems to be a safe and effective practice in 1-stage treatment of the previously injected lips with filler migration into ergotrid area.

Application of PLLA (Poly-L-Lactic acid) for rejuvenation and reproduction of facial cutaneous tissue in aesthetics: A review

Poly-L-lactin acid (PLLA) has been widely used in the field of bio-medicine. In 2004, as an injectable material, PLLA was approved by the FDA to treat AIDS-related facial atrophy. Since then, several injectable stuffs containing PLLA have been approved for marketing in various countries and regions. Recently, PLLA has often been used to treat facial rejuvenation problems like cutaneous depressions and static wrinkles which always induce unsatisfactory facial expression. This review introduces the physicochemical properties, regeneration stimulating mechanism, applications in aesthetics and injectable comorbidity of PLLA.

Facial artery: anatomical variations in the perioral region in cadavers

BACKGROUND

In recent years, there has been an increase in reports of perioral vascular complications resulting from filler injections, such as necrosis of the lip or alar rim, occlusion, and in severe cases, blindness. Conversely, the use of perioral arterial flaps is becoming more prevalent in the treatment of cleft lips, cancer, and trauma. A thorough understanding of perioral arteries is essential to minimize complications and maximize the success of these flaps. However, the course of the facial artery (FA) in the perioral region remains incompletely understood. The aim of this study was to describe the variations of the FA in the perioral region.

METHODS

We dissected 52 embalmed and formaldehyde-fixed Vietnamese cadavers. We then studied the size and distribution of perioral arteries in 102 specimens.

RESULTS

The superior labial artery (SLA) was the most common branch, occurring in 87.25% of cadavers, followed by the inferior labial artery (ILA) at 78.43%. The SLA primarily originated above the mouth corner (cheilion), accounting for 91.01% of cases, and predominantly exhibited a tortuous course within the submucosa (78.65%). The ILA's branching pattern varied, but it was primarily located below the cheilion (91.25%). The ILA also followed a twisted path, generally within the submucosa. The ILA exhibited two patterns: the typical pattern, distributed at the vermilion border of the lower lip (8.82%), and the horizontal labiomental artery pattern, which ran horizontally in the middle of the lower lip area (69.61%). At their origin, the SLA and ILA had average external diameters of 1.29 mm and 1.28 mm, respectively.

CONCLUSION

Numerous anatomical variations in the FA in the perioral region were found. A detailed anatomic description, suggested landmarks, and angiography before the procedure will be useful to help doctors avoid complications.

An illustrated anatomical approach to reducing vascular risk during facial soft tissue filler administration – a review

Vascular complications from soft tissue fillers can have catastrophic consequences for patients. Adverse events are rare, but they are increasing, and their appearance may be the result of intravascular injection. A comprehensive understanding of the 2-dimensional anatomy (distribution) and 3-dimensional anatomy (depth) of the facial vasculature is fundamental for the safe delivery of nonsurgical cosmetic procedures. The purpose of this review is to provide an illustrated approach to examine surgical anatomy specific to the facial vascular system and the anatomical considerations clinicians need to give in specific danger during injectable cosmetic procedures. A grounding in safety and anatomy will help the new injector to mitigate the risk of vascular complications.

Ultrasound Imaging of Facial Vascular Neural Structures and Relevance to Aesthetic Injections: A Pictorial Essay

The facial and submental regions are supplied by complicated neurovascular networks; therefore, facial aesthetic injections may be associated with serious adverse events such as skin necrosis and blindness. Pre-injection localization of neurovascular structures using high-resolution ultrasound can theoretically prevent unexpected complications. Therefore, a systematic protocol that focuses on these facial neurovascular structures is warranted. In this pictorial essay, we discuss the sonoanatomy of facial and submental neurovascular structures and its relevance to aesthetic injections. Moreover, we have highlighted the mechanisms underlying potential neurovascular injuries during aesthetic injections.

Efficacy and safety of hyaluronic acid fillers for lip augmentation in a Chinese population

BACKGROUND

Hyaluronic acid (HA) is an effective dermal filler for facial rejuvenation. This study aimed to observe the clinical efficacy of HA injection for lip augmentation in Chinese patients.

METHODS

From May 2019 to April 2020, 70 patients with lip fullness scale (LPS) ≤3 underwent local HA injection using the "three-point" injection technique. All patients were followed up to observe the clinical efficacy, LPS, adverse events, and complications.

RESULTS

All 70 patients were followed up for 12 months. Statistically significant improvements were observed in the height of lips within 6-9 months post-treatment (p < 0.05). The LFS improved significantly at follow-up compared with baseline (p < 0.05). Local redness occurred in two patients, and serious swelling occurred in three patients. These adverse events were generally tolerated and disappeared gradually within 1 week. No other serious adverse events and complications were reported in the remaining patients.

CONCLUSIONS

Hyaluronic acid injection can be used for lip augmentation in the Chinese population. The "three-point" technique is simple, safe, and effective and does not cause serious complications.

Superior labial artery and vein anastomosis configuration to be considered in lip augmentation

The treatment of cleft lip and palate is performed over a long period, starting immediately after birth. However, esthetic problems remain after lip augmentation. Endothelial cells of new capillaries are important for wound healing. Thus, the reconstruction of vascular networks is key to postoperative wound healing during lip augmentation. However, studies describing the superior labial artery (SLA) and superior labial vein (SLV) are rare, and their mutual positional relationship thus remains unclear. We procured 29 adult cadavers and ten fetuses. Macroscopic and histological examinations were performed on adult cadavers. We extracted soft tissues and blood vessels after micro-computed tomography (CT) and 3D tissue reconstruction. We performed histological investigations of vascular networks within the cleft lip in fetal samples. In adults, the SLV was distributed throughout the cutaneous side of the orbicularis oris muscle and the SLA, throughout the mucosal side. The SLV and SLA were separated by this muscle. Micro-CT images revealed that the SLA on the mucosal side transversed the orbicularis oris muscle to the SLV (55％). Histological analysis of fetuses revealed that the SLA was on the mucosal side, similar to that in adults, and traversed the orbicularis oris muscle in continuity with the SLV of the cutaneous side (100%). In lip augmentation, the reconstruction of the vascular structure, which involves the anastomosis of SLA and SLV passing through the orbicularis oris muscle, is an important factor when considering esthetic repair.

A Safe and Effective Lip Augmentation Method: The Step-by-Step Φ (Phi) Technique

The shape and fullness of the lips are essential in facial aesthetics. We describe a safe injection technique of hyaluronic acid (HA), based on the well-known golden number Φ (phi), for lip augmentation.

Anatomy of the Superior and Inferior Labial Arteries Revised: An Ultrasound Investigation and Implication for Lip Volumization

BACKGROUND

Lips are considered a key element of facial attractiveness due to their central position in the face and their elemental role in verbal and nonverbal communication.

OBJECTIVES

The authors sought to provide clinically relevant information on the 3-dimensional pathway of the superior and inferior labial arteries within the lips to increase safety during labial soft tissue filler injections.

METHODS

The study enrolled 41 healthy volunteers with a mean age of 26.17 ± 9.6 years and a mean body mass index of 23.09 ± 2.3 kg/m2. Ultrasound imaging was performed at 6 different locations. The position of the labial arteries within the lips, depth of the arteries, cranio-caudal location of each artery in relation to the vermilion border, and diameter of the superior/inferior labial arteries were recorded.

RESULTS

The most frequent location of both the superior and inferior labial arteries was the submucosal plane (58.5%) followed by intramuscular (36.2%) and subcutaneous (5.3%) planes. The depth of the superior labial artery in the upper lip was 5.6 ± 0.13 mm, whereas the depth of the inferior labial artery in the lower lip was 5.2 ± 0.14 mm. Both arteries were more frequently located within the red lip: upper lip (83% vs 18.7%) and lower lip (86.2% vs 13.8%). In the midline, the artery coursed within the red lip in all investigated volunteers.

CONCLUSIONS

Clinically, results of this study favor a superficial injection plane for lip volumization procedures. A perpendicular approach to the lip (coming from the cutaneous lip) might increase safety because the artery is located most frequently within the red lip.

Lip enhancement and mouth corner lift with fillers and botulinum toxin A

Beautiful lips are responsible for facial attractiveness and a youthful appearance. During aging process, lips become thinner and the red lips borders get poor defined. Downturn of the corners of the mouth suggests negative emotions. Lip surgery and underlying pathology may result in asymmetries and lip incontinence. Minor invasive procedures with hyaluronic acid fillers and botulinum toxin A are versatile tools to improve appearance of the lips, restore function and improve psycho-social well-being. In this review, we discuss anatomy, safety concerns, injections techniques as well as esthetic and medical indications.

Three-dimensional visualization of blood supply of the upper lip using micro-CT and implications for plastic surgery

INTRODUCTION

The anatomy of the arterial branches in the upper lip and their relationships to soft tissue are not well described in the literature. The purpose of this study was to explore a method for visualizing the microvessels and soft tissue three-dimensionally to gain better understanding of the upper lip blood supply.

MATERIALS AND METHODS

Seventeen stillborn fetuses were injected with lead oxide-gelatin and stained with iodine. Thirty-four half upper lip specimens were obtained and scanned by micro-computed tomography. The images were then examined and Inveon analysis software was used for three-dimensional reconstructions.

RESULTS

The main supplies to the upper lip were from the superior labial and inferior alar arteries. In some cases, the infraorbital and lateral nasal arteries also branched off to the upper lip. The anatomical variations were classified into six types on the basis of the observed vascular composition patterns. The skin was supplied by the subcutaneous vascular network, formed by the superficial ascending branches of the superior labial and inferior alar arteries. The mucosa was supplied by the submucosal vascular network, formed by the deep ascending branches of the superior labial artery and the labial branches of the infraorbital artery. The muscles were supplied by small vertical branches from the subcutaneous and submucosal vascular networks.

CONCLUSION

This study provides new anatomical insight into the upper lip by describing the microvessels and the relationship between the arteries and the soft tissue involved. This is important information for clinical applications in upper lip plastic surgery.

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.