Anatomy of Forehead, Glabellar, Nasal and Orbital Muscles, and Their Correlation with Distinctive Patterns of Skin Lines on the Upper Third of the Face: Reviewing Concepts

Integrative Assessment for Optimizing Aesthetic Outcomes When Treating Glabellar Lines With Botulinum Toxin Type A: An Appreciation of the Role of the Frontalis

Despite the perception that treatment of glabellar lines with botulinum toxin A is straightforward, the reality is that the glabellar region contains a number of interrelated muscles. To avoid adverse outcomes, practitioners need to appreciate how treatment of 1 facial muscle group influences the relative dominance of others. In particular, practitioners need to understand the independent role of the frontalis in eyebrow outcomes and the potential for negative outcomes if the lower frontalis is unintentionally weakened by botulinum toxin A treatment. In addition, practitioners must recognize how inter-individual variation in the depth, shape, and muscle fiber orientation among the upper facial muscles can affect outcomes. For optimal results, treatment of the glabellar complex requires a systematic and individualized approach based on anatomical principles of opposing muscle actions rather than a one-size-fits-all approach. This review provides the anatomical justification for the importance of an integrated assessment of the upper facial muscles and eyebrow position prior to glabellar treatment. In addition, a systematic and broad evaluation system is provided that can be employed by practitioners to more comprehensively assess the glabellar region in order to optimize outcomes and avoid negatively impacting resting brow position and dynamic brow movement.

LEVEL OF EVIDENCE: 5

An Exploration of the Anatomy of the Forehead of Asians and Its Relationship With Forehead Lines Based on Ultrasound Imaging

BACKGROUND

A profound understanding of the various frontal tissues' morphology and their relationship with forehead lines can efficiently guide clinical treatment.

OBJECTIVES

The authors explored the relationship between frontal anatomy and frontal lines.

METHODS

We measured the thickness and shape of tissues in different regions of the forehead of 241 Asians. Then, we analyzed the relationship between the types of frontalis muscle and frontal lines, as well as the relationship between the frontal anatomical structures and the production of frontal lines.

RESULTS

We classified the types of frontalis muscle into 3 categories comprising 10 subtypes. The skin (0.78 mm vs 0.90 mm, P < .05), superficial subcutaneous tissue (0.66 mm vs 0.75 mm, P < .05), and frontalis muscle thickness (0.29 mm vs 0.37 mm, P < .05) of people with obvious dynamic forehead lines were significantly thicker than those of people without significant dynamic forehead lines. However, no significant difference in the deep subcutaneous tissue thickness was found between people with and without static forehead lines (1.36 mm vs 1.34 mm, P < .05).

CONCLUSIONS

This study shows the relationship between the frontal structure and frontal lines. Therefore, these results can provide references for treating frontal lines, to a certain extent.

LEVEL OF EVIDENCE: 3

SAMCEP Society consensus on the treatment of upper facial lines with botulinum neurotoxin type A: A tailored approach

BACKGROUND

The safety and efficacy of botulinum neurotoxin type A (BoNTA) treatments are well established, but injection techniques, target muscles, and toxin doses continue to evolve, with each refinement producing improvements in treatment outcomes. The recommendations in this consensus move away from standard templates and illustrate how to tailor treatments to individual patterns and strengths of muscle activity, and patient preferences.

METHODS

Seventeen experts in the fields of plastic surgery, dermatology, ophthalmology, otorhinolaryngology, and neurology convened in 2022 to develop consensus-based recommendations for the use of botulinum toxin A for the treatment of horizontal forehead lines, glabellar frown lines, and crow's feet lines that reflect current clinical practice. The focus was on how to tailor injections to individual patients to optimize treatment outcomes.

RESULTS

For each upper face indication, consensus members describe how to perform a dynamic assessment to optimize the dose and injection technique for each patient. A tailored treatment protocol is presented for commonly observed patterns of dynamic lines. Units of Inco are defined and the precise location of injection points, illustrated with the use of anatomical images.

CONCLUSION

This consensus provides up-to-date recommendations on the tailored treatment of upper facial lines based on the latest research and collective clinical experience of the expert injectors. Optimal outcomes require thorough patient evaluation, both at rest and during animation, using both visual and tactile cues; detailed understanding of facial muscular anatomy and how opposing muscles interact; and use of a BoNTA with high precision to target identified zones of excess muscle activity.

Connections between postparotid terminal branches of the facial nerve: An immunohistochemistry study

It has been assumed that connections between the postparotid terminal branches of the facial nerve are purely motor. However, the nature of their fibers remains unexplored. The aim of this study is to determine whether these connections comprise motor fibers exclusively. In total 17 connections between terminal facial nerve branches were obtained from 13 different facial nerves. Choline acetyltransferase antibody (ChAT) was used to stain the fibers in the connections and determine whether or not all of them were motor. All connections contained ChAT positive and negative fibers. The average number of fibers overall was 287 (84-587) and the average proportion of positive fibers was 63% (37.7%-91.5%). In 29% of the nerves, >75% of the fibers were ChAT+ (strongly positive); in 52.94%, 50%-75% were ChAT+ (intermediately positive); and in 17.65%, <50% were ChAT+ (weakly positive). Fibers traveling inside the postparotid terminal cranial nerve VII branch connections are not exclusively motor.

Locking the line of convergence by botulinum toxin type A for the treatment of dynamic forehead wrinkles

BACKGROUND

Treatment of horizontal forehead lines with botulium toxin type A is a common procedure that helps achieve a youthful and rejuvenated look. Adequate knowledge of the anatomy and an individualized treatment approach is the key to successful treatment outcome.

AIM

To evaluate the cosmetic outcome following treatment of dynamic forehead wrinkles by locking the line of convergence using botulinum toxin type A.

PATIENTS AND METHODS

Fifty female patients with dynamic forehead wrinkles were included. The line of convergence was identified, and injection points were determined. Patients received injections of botulinum toxin type A in the upper part of the frontalis along the line of convergence. Patients were evaluated before injection and the response was evaluated after 2 weeks and after 3 months of injection.

RESULTS

Post-treatment significant decrease in dynamic wrinkle scale was detected. The distance between the medial and lateral canthi and their corresponding lower brow margins on maximum brow elevation was also significantly decreased after treatment. Meanwhile, the validated brow positioning score revealed no significant change in the resting brow position when pre-and post-treatment scores were compared.

CONCLUSIONS

Treating forehead wrinkles by injecting botulinum toxin along the line of convergence is an effective technique that requires less overall amount of toxin, improves the appearance of the wrinkles and minimizes the risk of development of side effects.

Avoiding Complications on the Upper Face Treatment With Botulinum Toxin: A Practical Guide

BACKGROUND

Currently, botulinum toxin (BoNT) injections are the most commonly performed non-invasive procedure for rejuvenation on the upper face. The therapeutic use of botulinum toxin has generally been safe and well tolerated. Adverse effects are considered mild, transient, and self-limited. However, as with all other injectable procedures, this one is also susceptible to adverse events and complications. When the safety zones are respected, the chance of any of these complications is practically null. Thus, this review aims to describe the main complications of treatment with BoNT on the upper face and to present a practical guide based on current evidence on how to avoid them.

METHODS

The literature research considered published journal articles (clinical trials or scientific reviews). Studies were identified by searching electronic databases (MEDLINE and PubMed) and reference lists of respective articles.

RESULTS

The main complications secondary to BoNT injections on the upper face are: ptosis of eyelid or eyebrow, eyebrow asymmetry, diplopia, Lakeophthalmos, Palpebral ectropion, and prominence of the palpebral bags. To avoid such complications, it is necessary to have knowledge of the anatomy of this region and adequate and individualized planning based on the existing patterns of the frontalis muscle, glabella, and crow's feet. This review presents the specificities of each of these regions and practical suggestions to obtain satisfactory results, avoiding complications.

CONCLUSION

Particularly on the upper face treatment with BoNT offers predictable results, has few adverse effects, and is associated with high patient satisfaction. However, it is suggested that the commented parameters and safety areas be incorporated into daily practice so that the possibilities of complications are minimized as much as possible.

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 .

Periorbital Filling With The MD Codes™ Algorithm: A Narrative Review and a Practical Guide

INTRODUCTION

The hyaluronic acid dermal fillers are employed to bring balance and facial harmony, improving the proportions and asymmetries of the structures, besides acting to reverse the signs of facial aging. The periorbital region is one of the first to show the signs of aging with periocular wrinkles, deepening of the nasojugal and palpebromalar folds, prolapse of the fat bags, excess palpebral skin, ptosis of the eyelashes, disappearance of the upper eyelid crease due to excess skin and hollowing of the upper eyelid.

AIMS

To describe the lines and grooves of the periorbital region and present a practical guide to the MD CODES™ algorithm for filling this region based on a narrative review of the literature.

METHODS

The literature research considered published journal articles (clinical trials or scientific reviews). Studies were identified by searching electronic databases (MEDLINE and PubMed) and reference lists of respective articles.

RESULTS

MD CODES™ algorithm maps anatomical points of the face (anatomical codes) that, when treated with fillers, promote instantaneous lifting and rejuvenation. In addition to defining the points for treatment, this method identified the order of the points to be treated, that is, which points should be prioritized to cause greater aesthetic impact. The MD CODES aim to standardize facial rejuvenation and is of particular interest for young as well as more experienced physicians.

CONCLUSION

Was presented in detail the regions, the aesthetic effects of the application, the technique, the volume, and the target structure undertaken in the remodeling of the tear trough, periorbital, temporal, brow, and frontal regions.

The One21 Technique: An Individualized Treatment for Glabellar Lines Based on Clinical and Anatomical Landmarks

PURPOSE

Botulinum toxin type A is an effective treatment for glabellar dynamic wrinkles. As the muscular group involved in the contraction of the glabella varies among people, individualized treatment can achieve optimal results. This study evaluates a customized assessment for the treatment of glabellar lines with Incobotulinumtoxin-A, leading to an individualized points distribution and dosage.

PATIENTS AND METHODS

A single-center, evaluator-blinded, therapeutic cohort study enrolled 130 women with moderate or severe glabellar wrinkles. They underwent Incobotulinumtoxin-A injection following the standard 5-point injection at the glabellar muscles (n = 65) or an individualized assessment and scheme treatment based on anatomical references of contraction, the One21 technique (n = 65). All the patients were photographed under maximum contraction before treatment (T0) and after 4 weeks (T28). The photos were randomly assessed by two blinded, experienced raters to consensually grade the severity according to the Merz Aesthetics Scales (MAS). The primary clinical efficacy was defined as a 2-point reduction in the MAS score, on Day 28.

RESULTS

The groups were homogeneous regarding age, phototype, and baseline MAS scores. On Day 28 (T28), 64 (98.5%) patients from the One21 group and 52 (80%) from the 5-point group reduced the MAS score by at least two points (p < 0.01). When adjusted by age and phototype, both groups reduced the MAS score at T28 (p < 0.01); nevertheless, patients from the One21 group significantly performed better (p < 0.01), with a much higher rate response rate at T28, in comparison to the 5-point group. Of patients enrolled in the 5-point group, 83.1% utilized muscle groups other than the procerus and corrugator in glabellar wrinkle formation, and 17 (24.6%) presented asymmetrical contraction. Patients from the 5-point group with glabellar asymmetry and those who utilized the frontalis and orbicularis presented inferior performance (p < 0.05), reinforcing the importance of an individualized assessment and treatment plan.

CONCLUSION

The One21 technique yielded better results than the standard 5-point treatment in reducing glabellar dynamic lines with Incobotulinumtoxin-A, especially for asymmetric lines of the glabella or the involvement of muscle groups other than the procerus and corrugator.

A Novel OnabotulinumtoxinA Treatment Technique to Obtain Predictable Outcomes in Eyebrow Position and Shape

Background

OnabotulinumtoxinA has been approved for multiple clinical and dermatological indications. The toxin, produced by the bacterium Clostridium botulinum, is undoubtedly the most widely used cosmetic treatment for both the reduction and prophylaxis of wrinkles in the upper face and the reshaping of the eyebrows. However, the aesthetic outcomes obtained with respect to eyebrow position and shape are not always predictable and furthermore, untoward effects such as eyelid and brow ptosis are sometimes seen.

Objective

This article suggests a novel injection technique of the upper face with OnabotulinumtoxinA to obtain predictable and reproducible results with respect to eyebrow position and shape, whilst greatly minimizing the risk of adverse effects such as brow and lid ptosis.

Discussion

OnabotulinumtoxinA inhibits the release of acetylcholine and results in the temporary paralysis of skeletal muscle. The aesthetic outcome of wrinkle reduction typically lasts for a period of 14–16 weeks. Although relatively safe in that the toxin does not have any irreversible side effects, even a temporary untoward reaction may be seriously distressing to the cosmetic patient.

Conclusion

The proposed injection technique, when diligently followed, ensures that the final eyebrow position is pleasing and symmetrical with a negligible risk of any untoward effects.

An Italian experience of a new personalized injective protocol (Botutouch) for botulinum toxin application in aesthetic medicine

Botulinum toxin typeA (BoNTA) is widely used in aesthetic medicine as primary treatment to reduce facial wrinkles. Major unmet needs in the field of the injection techniques include dilution factor, injected volume and site. Since 2013, an innovative protocol has been developed in our clinic that works on a double dilution volume, identifies the injection site according to the specific anatomical-functional characteristics of each patient's musculature and applies a gentle massage to the injected area to optimize the toxin spread in the muscle. We retrospectively retrieved medical records of subjects that underwent aesthetic treatments in our outpatient Italian clinics from 2013. In cobotulinum toxin A was used in double dilution (100 AU in 5 mL of physiologic solution) and followed by a gentle massage after the injection to increase the distribution into the muscle. 197 subjects, most of them drug-naïve (81.7%), underwent 869 BoNTA treatments. On average, higher total units and volumes were applied in first visits or older subjects whereas the lower ones were preferred in following visits or younger subjects. As perceived by the patients, the effects of BoNTA lasted more than 6 months in about 38% of the cases. 95.9% of subjects declared to be satisfied,whereas 5.2% of adverse events were observed (4.8% hematoma, 0.2% ptosis, and 0.2% tenderness). To date, we offer a BoNTA treatment with the aim to maximize the results and consequent patient's satisfaction, with low incidence of complications.

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).

Applied Anatomy for Botulinum Toxin Injection in Cosmetic Interventions

Purpose of Review

To provide the reader with a clear overview of facial anatomy as it relates to injection of botulinum toxin.

Recent Findings

The review suggests the presentation of multiple combinations of facial musculature, with the forehead, glabellar, and nasal base areas as particular areas of variation. Differences in musculature result in different wrinkling patterns; with age, these changes first become apparent in the upper face, particularly in the forehead and glabellar area.

Summary

Botulinum toxin is well suited to achieve the optimal outcome: it is popular, safe, and non-invasive and presents with few adverse effects. Though limited, when adverse effects do arise these are primarily related to poor injection technique, often fuelled by poor anatomical knowledge. For clinicians to achieve the best outcomes with botulinum toxin use, an understanding of the facial muscles’ anatomy, actions, and interactions is key. This paper discusses the broad and intricate detail regarding the key target muscles of botulinum toxin, based on both literature review and cadaveric dissection carried out by the authors.

OnabotulinumtoxinA Treatment for Moderate to Severe Forehead Lines: A Review

Background:

With onabotulinumtoxinA approved for the treatment of glabellar and crow’s feet lines and, most recently, for forehead lines (FHL), it is possible to simultaneously treat multiple areas of the upper face that are of high concern and treatment priority for aesthetically oriented individuals. This review aims to present key insights on the use of onabotulinumtoxinA for the treatment of moderate to severe FHL.

Methods:

Double-blind, placebo-controlled registration trials of onabotulinumtoxinA for the treatment of FHL were included. Using findings from 3 such published studies, we discuss key concepts and clinical experience for the treatment of moderate to severe FHL with onabotulinumtoxinA (20 U in the frontalis and 20 U in the glabellar complex, with/without 24 U in crow’s feet lines), including injection pattern, dose selection, efficacy and safety data, and considerations for patient selection.

Results:

Across the 2 pivotal phase 3 studies, responder rates on investigator- and subject-assessed measures of appearance of FHL severity were significantly higher with onabotulinumtoxinA versus placebo for the treatment of FHL at day 30 (P < 0.0001), and results were maintained through 3 cycles of onabotulinumtoxinA.

Conclusions:

OnabotulinumtoxinA treatment also resulted in high patient satisfaction rates. The incidence of eyebrow and of eyelid ptosis was low, and no new safety signals were detected. OnabotulinumtoxinA is safe and effective and an appropriate option for patients with moderate to severe FHL encountered in clinical practice.

A personalized treatment approach of frontalis muscle with botulinum toxin A (Bont-A) related to functional anatomy: case studies

Background: The forehead is one of the most frequent sites of botulinum toxin (Bont-A) application. To date, few data are available about the anatomy of the frontalis muscle. Its anatomy is highly heterogeneous in Caucasian people. Consequently, personalized treatments with botulinum toxin-A (Bont-A) are needed to obtain good esthetic results and to reduce side effects. Recently, a study on cadavers found four anatomical shapes of the frontalis muscle, corresponding to four horizontal wrinkle patterns in live patients.Objective: To perform a personalized, reproducible, and safer treatment with Bont-A of the forehead, by classifying patients according to four specific anatomical shapes of the frontalis muscle related to skin wrinkle patterns during contraction.Methods: We treated four patients classified according to the four anatomic types (I, II, III, and IV). The patients' forehead was divided into 21 areas and matched with 4 horizontal wrinkle patterns. Detecting different activities of the muscle in the different areas of the forehead, treatment injections were performed with a different dose, dilution, and at different anatomical layers (intramuscular or intradermal) per point.Conclusions: We confirmed four different wrinkle patterns after forehead contraction according to the anatomical shape of the frontalis muscle. This allows us to perform a tailored treatment with Bont-A. Nevertheless, some patients with atypical patterns still need "ad hoc" treatment.

One21: A Novel, Customizable Injection Protocol for Treatment of the Forehead with IncobotulinumtoxinA

It is well known that incobotulinumtoxinA (INCO) is an effective approved treatment for dynamic wrinkles of the upper face caused by the action of mimetic muscles over time. In doing so, it is important to maintain a balance between muscle groups and a natural facial appearance. Patients differ enormously in their facial anatomy regarding structure and function, both within and between genders, ethnicities, and age. Therefore, treating all patients with the same injection pattern and the same doses can result in undesired outcomes. There is a need for a tailored approach to achieve optimal results, as well as to increase patient satisfaction. With this in mind, the novel one21 injection technique which allows for individualized treatment has been developed for the treatment of horizontal forehead lines using INCO, resulting in a positive impact on eyebrow position and shape. This technique is the next step in a customized approach, giving natural-looking results and high patient satisfaction.

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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 .