Anatomy of the Lower Face and Botulinum Toxin Injections

IncobotulinumtoxinA for Aesthetic Treatments: Review and Recommendations From Latin America

BACKGROUND

As new aesthetic treatment techniques are developed, the understanding of botulinum toxin type A safety and treatment outcomes continues to evolve.

OBJECTIVE

This article was developed to provide a comprehensive up-to-date reference for clinicians using incobotulinumtoxinA (INCO; Xeomin/Bocouture, Merz Pharmaceuticals GmbH, Frankfurt, Germany) for aesthetic treatments.

PATIENTS AND METHODS/MATERIALS

A Latin American panel of 11 physicians was assembled to discuss and develop recommendations on the use of INCO for aesthetic treatment based on the literature review and their private medical practice.

RESULTS

The panel found that INCO is a highly purified botulinum toxin, without other clostridial proteins (hemagglutinins and nonhemagglutinins). IncobotulinumtoxinA has proven its efficacy and duration over time, maintaining response after multiple treatment cycles.

CONCLUSION

This recommendation provides up-to-date information on the use of INCO for aesthetic treatment, focusing on the differential properties of this product regarding its purity, performance, customization, and patient satisfaction.

Lifting With Neuromodulators

BACKGROUND

The use of botulinum toxins for facial rejuvenation and improvement of dynamic wrinkles has become a mainstay in the aesthetic treatment armamentarium. However, using these same neuromodulators (NMs) for lifting the structures of the face, is a newer addition to antiaging protocols. The muscles of facial animation all interplay with each other. Lifting can be accomplished by treating those muscles that are responsible for depression, leaving the elevators unopposed and resulting in a rejuvenated, lifted outcome. Brow lifting, cheek lifting, and even contouring of the lower face and jawline are all possibilities using NMs.

OBJECTIVE

To review the literature and current practices in techniques for lifting the different anatomic facial zones.

METHODS

The authors present and discuss the published data and personal experiences of using NM for lifting and retraining of the facial musculature. This article will discuss the effects and approaches to lifting with botulinum toxin injections, including the potential success and side effects associated with these off-label injections.

RESULTS/CONCLUSIONS

The use of botulinum toxins has expanded beyond its traditional use as a reducer of dynamic wrinkles. A significant amount of published data now exists for the off-label use of botulinum toxins for lifting and shaping the face. These can be considered advanced techniques as each region has its own anatomic intricacies and side effects can occur. More placebo-controlled objective data would also help elucidate exact dosing strategies for each region.

Preoperative assessment of depressor anguli oris to prevent myectomy failure: An anatomical study using high-resolution ultrasound

BACKGROUND

Myectomies of the lower lip depressor muscles have unexplained high failure rates. This study aimed to examine the depressor anguli oris (DAO) muscle using high-resolution ultrasound to identify potential anatomical explanations for surgical failures and to determine the accuracy of utilizing preoperative ultrasound assessment to improve myectomies.

METHODS

Anatomical features of DAO and the surrounding anatomy were examined in 38 hemifaces of human body donors using high-resolution ultrasound and dissection.

RESULTS

The ultrasound and dissection measurements showed the DAO muscle width to be 16.2 ± 2.9 versus 14.5 ± 2.5 mm, respectively, and the location of the lateral muscle border 54.4 ± 5.7 versus 52.3 ± 5.4 mm lateral to the midline. In 60% of the cases, the facial artery was either completely covered by lateral DAO muscle fibers or was found to be in direct contact with the lateral border. Significant muscle fiber continuity was present between the DAO and surrounding muscles in 5% of cases, whereas continuity between the depressor labii inferioris and surrounding muscles was considerably more common and pronounced.

CONCLUSIONS

High-resolution ultrasound can accurately reveal important preoperative anatomical information in myectomies. Two potential explanations for the surgical failures were discovered: an overlap of lateral DAO muscle fibers over the facial artery could lead to inadequate resections and continuity with the surrounding muscles might lead to muscle function takeover despite adequate resections. Both can be uncovered preoperatively by the surgeon through a brief, directed ultrasound examination, which may allow for modification of the surgical plan to reduce surgical failure.

Sonoanatomy of the platysmal bands: What causes the platysmal band?

BACKGROUND

The platysmal band is created by the platysma muscle, a thin superficial muscle that covers the entire neck and the lower part of the face. The platysmal band appears at the anterior and posterior borders of the muscle. To date, no definite pathophysiology has been established. Here, we observed a lack of knowledge of the anatomy of the platysma muscle using ultrasonography in this study.

METHODS

We conducted a descriptive, prospective study observing the platysmal band in resting and contraction states to reveal muscle changes. Twenty-four participants (aged 23-57 years) with anterior and posterior neck bands underwent ultrasonography in resting and contracted states. Ten cadavers were studied aged 67-85 years to measure the thickness of the platysma muscle at 12 points: horizontally (medial, middle, lateral) and vertically (inferior mandibular margin, hyoid bone, cricoid cartilage, superior margin of clavicle).

RESULTS

The anterior and posterior borders of the platysma muscle were thicker than the middle of the platysma muscle when in a contracted state, and the muscle also had a convex shape when contracted. The thickness of the platysma muscle was not significantly different over 12 points in the resting state. During contraction, the platysma muscles contracted in the medial and lateral margins of the muscle, which was more significant in the posterior bands.

CONCLUSION

The anterior and posterior platysmal bands are related to muscle thickness during contraction. These observations support the change in platysmal band treatment only at the anterior and posterior border of the muscle.

Safety considerations for treating the parotid and submandibular glands with neuromodulators for facial slimming

BACKGROUND

Neuromodulators have predominantly been used for the treatment of upper facial lines, but their use has expanded to include lower face and neck treatments. However, the injection sites for these treatments are based on skin surface landmarks, which may pose risks to nearby structures and result in undesired outcomes.

OBJECTIVE

To investigate the spatial relationship between the FDA-approved skin surface landmarks for neuromodulator injections in the parotid and submandibular glands and the topographical anatomy of critical facial structures such as the facial artery, facial vein, external carotid artery, and retromandibular vein.

MATERIALS AND METHODS

A cross-sectional retrospective analysis was conducted on contrast-enhanced cranial CT scans. The scans were analyzed for the morphology and location of the parotid and submandibular glands. Measurements were taken for gland volume, craniocaudal extent, anterior-posterior extent, and distances between the skin surface and gland capsule or nearby structures such as arteries.

RESULTS

The study sample consisted of 53 subjects, including 7 males and 46 females, with a mean age of 36.91 years and a mean BMI of 23.28 kg/m2 . The mean volume of the parotid gland was 31.9 ± 3.0 cc in males and 28.5 ± 3.6 cc in females with p < 0.001, while the mean volume of the submandibular gland was 18.2 ± 2.0 cc in males and 14.5 ± 3.4 cc in females with p < 0.001. The mean distances between skin surface and the gland capsule were 5.98 ± 2.2 and 8.84 ± 4.0 mm for the parotid and submandibular gland, respectively. This distance increased with higher age and higher BMI values in a statistically significant manner with p < 0.001.

CONCLUSION

The distances between FDA-approved skin surface landmarks and the parotid and submandibular glands varied significantly depending on gender, age, and BMI. Optimal injection depth and location for neuromodulator treatments cannot be generalized based on these landmarks alone, emphasizing the need for real-time ultrasound imaging guidance.

A Novel 3-Point Injection Technique for OnabotulinumtoxinA in the Upper Depressor Anguli Oris

BACKGROUND AND OBJECTIVE

To evaluate the efficacy and safety of onabotulinumtoxinA (ONA) injections to the depressor anguli oris (DAO) to improve downturned mouth.

PATIENTS AND METHODS/MATERIALS

This prospective, placebo-controlled, study enrolled subjects aged 18 to 65 years. Injections were performed using a novel 3-point technique in the upper DAO (1.5 U/injection site). The primary end point was a DAO contraction scale 1-grade improvement. Subjective evaluation was performed using the Global Aesthetic Improvement Scale (GAIS).

RESULTS

Ten subjects received ONA and 10 placebo (saline) injections. In ONA-treated subjects, DAO scores showed significant improvements at Weeks 4 and 12 ( p < .001) compared with baseline. No significant difference between visits was observed for placebo-injected subjects. Global Aesthetic Improvement Scale scores showed that 100% of subjects were improved compared with baseline at Week 4% and 90% at Week 12. By contrast, 90% and 80% of placebo-treated subjects had "no change" in their DAO appearance at Weeks 4 and 12. Subject GAIS assessments matched the live evaluator at Week 4; 60% continued to report improvement at Week 12. Treatment was well tolerated.

CONCLUSION

OnabotulinumtoxinA injections to the DAO using a 3-point technique provide clinically meaningful improvements in appearance. Treatment was well tolerated and in most individuals lasted at least 12 weeks.

IDENTIFIER

ClinicalTrials.gov NCT04240535.

The Underappreciated Role of the Platysma Muscle in the Perioral Expressions in Young Adults

BACKGROUND

The platysma is involved in lower face movement, yet limited information on its functional role when making perioral expressions is available.

OBJECTIVES

The aim of this study was to use 3-dimensional (3D) photogrammetry to analyze platysma activity when making expressions.

METHODS

Standardized frontal-view 3D images were obtained from 54 volunteers. Three perioral expressions were analyzed: a full smile, mouth corner depression, and a grimace to show the lower teeth. Positive volume change in the "heat map" of the neck skin surface-determined by the superimposed image subtraction technique-served as a sensitive indicator of platysma contraction.

RESULTS

When making the 3 expressions, the proportions of platysma contraction were 42.6%, 75.9%, and 92.6%, respectively. The platysma worked as a more critical dynamic force than expected. In most smiles involving the platysma, its upper portion contracted. With the laterally downward traction on the lower lip increasing, the upper and lower portions of the platysma contracted together and formed muscular bands. The platysma contracted extensively in the other 2 expressions. In some cases, platysma bands were observed to form due to vigorous contraction of muscle fibers. In addition, the platysma was found to be highly functionally active in young individuals.

CONCLUSIONS

This study introduced a simple method that can sensitively identify the functional status of the platysma. The results showed the platysma's highly active function in perioral expressions in young adults. These findings may assist surgeons in personalized decision-making toward platysma muscle-weakening strategies and work as an objective tool for outcome evaluation.

LEVEL OF EVIDENCE: 4

Botulinum toxin A in dentistry and orofacial surgery: an evidence-based review - part 2: cosmetic applications

Objective An evidence-based review on the role of botulinum toxin type A (BoNTA) on diverse cosmetic applications of interest to dental practitioners and allied specialities. In this context, to identify the cosmetic treatments that have an evidence-based rationale against areas requiring further research, with a view to assess the safety and efficacy of BoNTA.Data source and selection A comprehensive search was conducted using Cochrane Library of Systematic Reviews, Cochrane Central Register of Controlled Trials, and PubMed (Medline) electronic databases. Thirty-nine studies of variable quality were included. The Best Evidence Topics (BETs) Critical Appraisal Tool was used to facilitate the quality assessment of relevant studies.Data extraction Based on current level II evidence, BoNTA was safe and effective to improve facial contour, reduce volume and thickness of bilateral hypertrophic masseter. Conservative doses using a combined approach of BoNTA and hyaluronic acid was recommended as a safe and effective treatment for perioral enhancement supported by level II evidence. There was limited evidence, not higher than level III, to support BoNTA effectiveness for gummy smile associated to perioral musculature hyperactivity, while jawline sculpting targeting the platysma muscle had lower level IV evidence up to this date.Conclusion BoNTA has been widely used off-label for the investigated cosmetic orofacial conditions, with reports of 'good patient and practitioner satisfaction'. However, there is limited high-quality evidence to support the long-term safety and effectiveness of repetitive BoNTA injections. Additionally, no studies were found that provided a cost-effectiveness evaluation of BoNTA formulations against other current cosmetic interventions. Well-designed clinical trials, including long-term follow-up, would help to provide robust evidence-based recommendations for clinical practice, supporting BoNTA popularity, independently or in a combined approach.

Creating Lift in the Lower Face With Botulinum Toxin A Treatment: An Anatomical Overview With Videos and Case Studies Illustrating Patient Evaluation and Treatment

Background

Relaxation of depressor muscles in the lower face with botulinum toxin A (BoNT-A) can create a lifting effect and dramatically improve jawline contour and resting facial expression. Even with the recent increase in interest in lower face rejuvenation, BoNT-A is a relatively under-recognized tool for treatment of this area. When treating the lower face, an understanding of anatomy and the relationship between the facial muscles is especially important, as injection patterns must be customized for consistently positive outcomes.

Objectives

This study was aimed to provide basic knowledge of the activities of the muscles in the lower face and neck and to describe the basis for injecting BoNT-A to create lift in this area. Expert guidance for injection is also provided.

Methods

As part of a continuing medical education course on differentiating botulinum toxin products, a panel of 4 expert physician injectors participated in a live webinar to discuss the implications of increasing toxin use.

Results

The practical guidance in this manuscript is based on the most frequently requested information by audience members and the information considered critical for success by the authors. The authors outline the functional anatomy of the lower face most relevant for BoNT-A treatment and case studies as well as methods for patient evaluation and injection technique are also provided. Videos showing treatment planning and injection technique for the lower face and neck are included.

Conclusions

BoNT-A is an important nonsurgical tool for creating lift in the lower face.

Level of Evidence 5

Current Use of Cosmetic Toxins to Improve Facial Aesthetics

LEARNING OBJECTIVES

After studying this article, the participant should be able to: 1. Compare and contrast the various types of botulinum toxin on the market. 2. Appropriately select patients for treatment with cosmetic botulinum toxin. 3. Understand the common injection patterns for treating various regions of the face with cosmetic botulinum toxin. 4. List the complications associated with treating various regions of the face with cosmetic botulinum toxin.

SUMMARY

Nonsurgical rejuvenation of the face with botulinum toxin is one of the most commonly performed procedures in the United States. This article reviews the current evidence in treating different regions of the face: upper face, lower face, masseter, and platysma. Dosing and complications associated with different facial regions are reviewed.

The Ideal Lips: Lessons Learnt from the Literature

Defining the ideal dimensions and proportions of the human face has been attempted for centuries, popularised in the Renaissance period by artists including Leonardo Da Vinci. The lips are part of the lower third of the face and are central to lower face aesthetics and the overall symmetry of the face. They also place an important part in conveying facial emotions and expressions. Full lips with well-defined Cupid's bow have always been associated with youth and beauty. The approval of hyaluronic acid use for tissue augmentation and the prevalence of social media have caused an exponential increase in lip augmentation procedures (Linkov et al. in Arch Plast Surg 46(3):248-254, 2019), as such researchers and aestheticians have focused on characterising the ideal lips mathematically to help guide clinicians. This narrative review will summarise the available evidence in the literature pertaining to the ideal lips, taking into account age, ethnicity and gender differences. LEVEL OF EVIDENCE III: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Topographic anatomical localization of the motor nerve entry points (MEPs) of the masseter muscle

PURPOSE

The masseteric nerve, which is a branch of the mandibular nerve, passes lateral to the mandibular notch and then spreads in the muscle to achieve motor innervation. The muscle entry points of these motor branches are the target points of minimally invasive interventions preferred in the treatment of masseter hypertrophy. The aim of this study was to reveal the areas where the motor entry points are concentrated in the muscle by dividing the muscle into topographic regions using reliable anatomic landmarks.

METHODS

Bilateral 20 masseter muscles (40 in total) belonging to 20 formalin-fixed cadavers (10 female and 10 male) were examined. The distribution of the nerve in the muscle and its motor entry points were demonstrated and marked on the muscle surface. The masseter muscle was divided into six areas by lines passing through reliable anatomical landmarks (Areas 1-6).

RESULTS

The total number of MEPs was 231.The mean distance of the MEPs from the Line-1 was 27.4 ± 11 mm, and the same distance from the Line-6 was 30.32 ± 7.2 mm. Most of the MEPs (123/231) were located in Area-4. Area-6 was the second (82/231) and Area-5 (19/231) was the third.

CONCLUSION

We suggest that interventions in Area-4 (especially in the middle part) may have less complications as a result of less relationship with surrounding anatomical structures and more effective with high MEP number.

Hyperhidrosis and Aesthetics

When one considers the avalanche of new indications and uses for botulinum toxins, it is truly surprising that this has all happened in such a short time. And the safety and dependability of these products are profound, when used appropriately. There is still much to be discovered about the potential of this agent when you contemplate the profound non-cosmetic benefits reported by clinicians and scientists from around the world. The mechanism of action has been studied in depth, and yet the benefits appreciated by people with chronic migraine or major depressive disorder, for instance, are unlikely to be explained by our current mechanistic understanding. Given that these toxins control acetylcholine at the motor end plates, and given that acetylcholine is central to practically every cell in the body, it will not be surprising to find that botulinum toxin researchers will be enjoying many decades of fruitful studies. The advent of the non-surgical aesthetic physician has helped push the clinical utilization of botulinum toxins well beyond its original adoption by oculoplastic surgeons in their patients with blepharospasm. We can expect that the next edition of this book to have a dozen or more new indications which will surprise us all.

The Anatomy of the Temporal and Zygomatic Branches of the Facial Nerve: Application to Crow's Feet Wrinkles

BACKGROUND

Advances in the understanding of wrinkling crow's feet while improving the safety and efficacy of botulinum toxin type A injection has pointed to drug dispersion in the lateral orbital wrinkles as a cause of adverse events of botulinum toxin type A injection. The purpose of this study is to identify the distribution of temporal and zygomatic branches of facial nerve in the orbicularis oculi muscles.

METHODS

Anatomical dissection of cadavers was performed in 31 cadavers, 13 females and 18 males, with ages ranging from 20 to 60 years, which of all had been embalmed by 10% formalin solution. The facial nerve was identified within subcutaneous tissue close periorbital region and both traced proximal and distal. Its temporal branch, zygomatic branch, facial and muscular entrance were located and accurately measured relative to established surface landmarks.

RESULTS

Dissection of the facial nerve revealed 2 to 6 entrances of the temporal branch into the orbicularis oculi and 1 to 5 entrances of the zygomatic branch into the orbicularis oculi. Concerning the measurements of neural entering points, distance and angle from orbicularis oculi muscle to lateral ocular angle, a distribution map of its muscular entrance and their patterns of distribution were constructed. According to the dense area of the coordinate map, there were 3 points determined as the muscular entrance points to established surface landmarks.

CONCLUSIONS

An anatomical dissection of cadavers was performed to identify the distribution of temporal and zygomatic branches of the facial nerve in the orbicularis oculi. According to the dense area of the coordinate map, the surface landmarks of 3 points were established as the muscular entrance of the facial nerve (MEF).

Effects of different doses of abobotulinumtoxinA for the treatment of anterior gingival smile

Botulinum toxin type A (BoNT-A) is an easy and fast treatment for gingival smile (GS). The objective of the study was to compare the reduction of gingival exposure using three different doses of abobotulinumtoxinA (ABO) in patients with different severities of anterior GS, and to assess treatment safety and patients' satisfaction. A prospective, single-center, randomized, double-blind study was conducted. Mild GS (2 to < 3 mm) was treated with 2.5 U of abobotulinumtoxinA (ABO) per side, moderate GS (3 to < 4 mm) with 5 U of ABO per side, and severe GS (4 mm or more) with either 2.5 U, or 5 U or 7.5 U of ABO per side. All the 41 enrolled patients completed the study. The mean gingival exposure reduced significantly 4 and 12 weeks after treatment. The average reduction of gingival exposure with 5 U was significantly larger than that obtained with 2.5 U, (3.46 ± 1.39 vs. 2.05 ± 1.29 mm; p = 0.004). All groups of GS severity presented statistically significant reduction in the gingival exposure 4 and 12 weeks after ABO injections. Twelve weeks after treatment, more than 80% of the patients were satisfied or very satisfied. There were no treatment-related adverse events reported by the patients or noticed by the investigators. Gingival smile can be safely and effectively managed with BoNT-A injections and specifically with ABO injections to target the LLSAN muscle. Further and larger studies may determine the exact influence of each factor on BoNT-A treatments of GS.

A Prospective Observational Study of the Effectiveness and Safety of Botulinum Toxin in the Horizontal Neck Lines

BACKGROUND

Botulinum toxin is used extensively, and its use for aesthetic indications in the lower face and neck is now becoming increasingly popular. It is the ideal alternative to surgical procedures for patients who are too young for facelift surgery or who are unwilling to take recuperation time. We review current approaches to BTX A treatment for horizontal neck lines.

METHODS

Subjects were 20 women with an average age of 43 with mild to moderate horizontal neck lines but have had no treatment by BTX A for the past 3 months. Injections are performed at points 1-1.5 cm apart along the horizontal lines with 1-2 U in each injection site, for a total of 15-30 U. Patients were followed up 3 and 8 days after treatment and then every 4 weeks after initial treatment for 16 weeks.

RESULTS

Except day 3 in the first neck line, the mean resulting from evaluation by the actual physician who performed the injection and two blinded physicians has statistical significance as shown by the maximum results at 8 weeks after injection. However, the patient improvement rate and satisfaction level did not exceed 50%. Adverse reactions were mild and transitory.

CONCLUSIONS

The overall results of applying BTX A are excellent, and the satisfaction level of treated patients is high to a certain extent. Moreover, smoothening of the neck skin was observed due to the intradermal effect. It is also a safe and effective therapeutic modality for any patient desiring rejuvenation of his or her neck, but who at the same time does not desire any recuperation time or is unwilling to undertake the potential risks associated with surgical procedures.

LEVEL OF EVIDENCE IV

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Muscle Insertion and Strength of the Muscle Contraction as Guidelines to Enhance Duration of the Botulinum Toxin Effect in the Upper Face

BACKGROUND

In this series of patients the cutaneous insertion and strength of voluntary contraction of the muscles in the upper third of the face were used as guidelines for botulinum toxin application named "BTA Codes."

METHOD

Anatomical dissection of fresh cadavers identified the shape and cutaneous insertions of the muscles in the upper third of the face. Patient voluntary contraction of the muscles in the upper third of the face created different patterns of skin lines classified by the 4-grade Facial Wrinkle Scale. For botulinum toxin application injections points followed the muscle cutaneous insertion and dose the 4-grade Facial Wrinkle Scale.

RESULTS

Injection points ranged from 3 to 23 points per patient, average of 9.4 points. Dose per point varied from 2.5 to 7.5 U, ranging from 12.5 to 72.5 U per patient, average of 33.82 U. Skin lines resulting from the voluntary contraction of the muscle prior to toxin application were stated as baseline 1. The absence of skin lines and muscle activity on day fifteen after toxin application defined baseline 2. Skin lines resulting from the recovered voluntary contraction of the muscle after toxin application like those of baseline 1 established baseline 3. The botulinum toxin effect was the time elapsed between baselines 2 and 3, ranging from 171 to 204 days, average of 183.72 days, greater than the 3 or 4 months reported in the literature.

CONCLUSION

"BTA Codes" is a set of rules to apply botulinum toxin supported by muscle anatomy and degree of voluntary contraction to enhance the duration of its effect.

LEVEL OF EVIDENCE IV

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

New Insights into the Anatomy of the Midface Musculature and its Implications on the Nasolabial Fold

BACKGROUND

The prominent nasolabial fold is a distinct feature of the aging midface. As minimally invasive procedures have become mainstream, chemodenervation is a preferred method for treating dynamic facial rhytids. We therefore sought to identify relevant nasolabial fold and midfacial muscular anatomy to determine the ideal location of neuromodulation to improve the aesthetics of the midface and nasolabial fold without altering the upper lip and smile.

METHODS

Twelve hemifacial cadaveric dissections were performed to identify midface muscle origin, insertion, width, vector of pull, and neighboring structures. Attention was focused on the levator labii superioris alaeque nasi (LLSAN), levator labii superioris (LLS), nasalis, and orbicularis oculi. Measurements were obtained based on surface landmarks including the medial canthus for future neurotoxin injection.

RESULTS

The LLSAN inserts into the medial nasolabial fold and alar base, while the LLS inserts into the middle third of the nasolabial fold. The broadest portion of the superior LLSAN was on average 8.4 mm inferior and 4.6 mm medial to the medial canthus. A separate muscle obliquely oriented between the orbicularis oculi and LLSAN was identified and found to insert into the malar fat pad. This "malar levator" was present in all specimens and has implications on medial periorbital rhytids and the tear trough deformity.

CONCLUSION

This study further defines midfacial and nasolabial fold muscular anatomy and provides new insights into the use of neuromodulators for these areas without affecting upper lip position. The malar levator muscle appears to be a separate midfacial muscle with independent action.

LEVEL OF EVIDENCE V

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Injectable and topical neurotoxins in dermatology: Basic science, anatomy, and therapeutic agents

Botulinum toxin is a potentially deadly anaerobic bacterial toxin that acts by inhibiting release of acetylcholine at the neuromuscular junction, thereby inhibiting contraction of the exposed striated muscle. There are currently 4 botulinum toxin preparations approved by the US Food and Drug Administration (FDA): onabotulinumtoxin, abobotulinumtoxin, incobotulinumtoxin and rimabotulinumtoxin. While significant overlap exists, each product has unique properties and specifications, including dosing, diffusion, and storage. Extensive physician knowledge of facial anatomy, coupled with key differences of the various neurotoxin types, is essential for safe and successful treatments. The first article in this continuing medical education series reviews key characteristics of each neurotoxin, including new and upcoming agents, and provides an anatomic overview of the most commonly injected cosmetic sites.

Review of 3-dimensional Facial Anatomy: Injecting Fillers and Neuromodulators

Supplemental Digital Content is available in the text.

To achieve consistent results utilizing facial injectables, practitioners must understand the pertinent anatomy of the forehead, temple, cheek, nose, and perioral areas. A detailed understanding of facial blood vessels, nerves, and musculature is essential for safe and effective placement of fillers and neuromodulators.

Age-Related Changes of the Orolabial Region in Caucasian Women: An Anthropometric Analysis

PURPOSE

Anthropometric data can provide valuable support for the attending physician in planning surgical and nonsurgical esthetic procedures with regard to a patient's age. The purpose of the present study was to identify age-related orolabial changes in younger and older Caucasian women.

MATERIALS AND METHODS

In the present cross-sectional study, anthropometric landmarks were identified using indirect anthropometry (2-dimensional photometry) in younger (≤35 yr) and older (≥50 yr) Caucasian women to analyze age-related parameters and proportions of the orolabial region, especially of the lower and upper lip vermilion areas. The Mann-Whitney U test was applied to compare the results between the younger and older populations.

RESULTS

The study population consisted of 45 women. The cohort was divided into a younger population (24 participants; mean age, 27.4 yr) and an older population (21 participants; mean age, 58 yr) to evaluate age-related differences. Increases of upper lip height, cutaneous height of the upper lip, and cutaneous height of the lower lip were observed in older women. In contrast, the vermilion height of the lower lip decreased significantly with increasing age.

CONCLUSION

These results show changes of the orolabial region occur in Caucasian women with increasing age. The statistically relevant decrease of the vermilion height of the lower lip should be given particular attention for (age-appropriate) diagnostic, esthetic, and prosthetic treatment planning.