Mark Taliercio, BS

Several concepts of ideal aesthetic measurements can be traced back to ancient Greek and European Renaissance art. In examining canons of beauty, these classical ideals often are compared to modern-day standards, allowing clinicians to delineate the parameters of an attractive facial appearance and facilitate the planning of cosmetic procedures.

Given the growing number of available cosmetic interventions, dermatologists have a powerful ability to modify facial proportions; however, changes to individual structures should be made with a mindful approach to improving overall facial harmony. This article reviews the established parameters of facial beauty to assist the clinician in enhancing cosmetic outcomes.

Canons of Facial Aesthetics

Horizontal Thirds
In his writings on human anatomy, Leonardo da Vinci described dividing the face into equal thirds (Figure 1). The upper third measures from the trichion (the midline point of the normal hairline) to the glabella (the smooth prominence between the eyebrows). The middle third measures from the glabella to the subnasale (the midline point where the nasal septum meets the upper lip). The lower third measures from the subnasale to the menton (the most inferior point of the chin).¹

Although the validity of the canon is intended to apply across race and gender, these proportions may vary by ethnicity (Table). In white individuals, the middle third of the face tends to be shorter than the upper and lower thirds.² This same relationship has been observed in black males.³ In Chinese females, the upper third commonly is shorter than the middle and lower thirds, correlating with a less prominent forehead. In contrast, black females tend to have a relatively longer upper third.⁴

The relationship between modern perceptions of attractiveness and the neoclassical norm of equal thirds remains a topic of interest. Milutinovic et al¹ examined facial thirds in white female celebrities from beauty and fashion magazines and compared them to a group of anonymous white females from the general population. The group of anonymous females showed statistically significant (P<.05) differences between the sizes of the 3 facial segments, whereas the group of celebrity faces demonstrated uniformity between the facial thirds.¹

The lower face can itself be divided into thirds, with the upper third measured from the subnasale to the stomion (the midline point of the oral fissure when the lips are closed), and the lower two-thirds measured from the stomion to the menton (Figure 1). Mommaerts and Moerenhout⁵ examined photographs of 105 attractive celebrity faces and compared their proportions to those of classical sculptures of gods and goddesses (antique faces). The authors identified an upper one-third to lower two-thirds ratio of 69.8% in celebrity females and 69.1% in celebrity males; these ratios were not significantly different from the 72.4% seen in antique females and 73.1% in antique males. The authors concluded that a 30% upper lip to 70% lower lip-chin proportion may be the most appropriate to describe contemporary standards.⁵

Vertical Fifths
In the vertical dimension, the neoclassical canon of facial proportions divides the face into equal fifths (Figure 2).⁶ The 2 most lateral fifths are measured from the lateral helix of each ear to the exocanthus of each eye. The eye fissure lengths (measured between the endocanthion and exocanthion of each eye) represent one-fifth. The middle fifth is measured between the medial canthi of both eyes (endocanthion to endocanthion). This distance is equal to the width of the nose, as measured between both alae. Finally, the width of the mouth represents 1.5-times the width of the nose. These ratios of the vertical fifths apply to both males and females.⁶

Anthropometric studies have examined deviations from the neoclassical canon according to ethnicity. Wang et al⁷ compared the measurements of North American white and Han Chinese patients to these standards. White patients demonstrated a greater ratio of mouth width to nose width relative to the canon. In contrast, Han Chinese patients demonstrated a relatively wider nose and narrower mouth.⁷

In black individuals, it has been observed that the dimensions of most facial segments correspond to the neoclassical standards; however, nose width is relatively wider in black individuals relative to the canon as well as relative to white individuals.⁸

Milutinovic et al¹ also compared vertical fifths between white celebrities and anonymous females. In the anonymous female group, statistically significant (P<.05) variations were found between the sizes of the different facial components. In contrast, the celebrity female group showed balance between the widths of vertical fifths.¹

Lips
In the lower facial third, the lips represent a key element of attractiveness. Recently, lip augmentation, aimed at creating fuller and plumper lips, has dominated the popular culture and social media landscape.⁹ Although the aesthetic ideal of lips continues to evolve over time, recent studies have aimed at quantifying modern notions of attractive lip appearance.

Popenko et al¹⁰ examined lip measurements using computer-generated images of white women with different variations of lip sizes and lower face proportions. Computer-generated faces were graded on attractiveness by more than 400 individuals from focus groups. An upper lip to lower lip ratio of 1:2 was judged to be the most attractive, while a ratio of 2:1 was judged to be the least attractive. Results also showed that the surface area of the most attractive lips comprised roughly 10% of the lower third of the face.¹⁰

Penna et al¹¹ analyzed various parameters of the lips and lower facial third using photographs of 176 white males and females that were judged on attractiveness by 250 volunteer evaluators. Faces were graded on a scale from 1 (absolutely attractive) to 7 (absolutely unattractive). Attractive males and females (grades 1 and 2) both demonstrated an average ratio of upper vermilion height to nose-mouth distance (measured from the subnasalae to the lower edge of the upper vermilion border) of 0.28, which was significantly greater than the average ratio observed in less attractive individuals (grades 6 or 7)(P<.05). In addition, attractive males and females demonstrated a ratio of upper vermilion height to nose-chin distance (measured from the subnasalae to the menton) of 0.09, which again was larger than the average ratio seen in less attractive individuals. Figure 3 demonstrates an aesthetic ideal of the lips derived from these 2 studies, though consideration should be given to the fact that these studies were based in white populations.

Golden Ratio
The golden ratio, also known as Phi, can be observed in nature, art, and architecture. Approximately equal to 1.618, the golden ratio also has been identified as a possible marker of beauty in the human face and has garnered attention in the lay press. The ratio has been applied to several proportions and structures in the face, such as the ratio of mouth width to nose width or the ratio of tooth height to tooth width, with investigation providing varying levels of validation about whether these ratios truly correlate with perceptions of beauty.¹² Swift and Remington¹³ advocated for application of the golden ratio toward a comprehensive set of facial proportions. Marquardt¹⁴ used the golden ratio to create a 3-dimensional representation of an idealized face, known as the golden decagon mask. Although the golden ratio and the golden decagon mask have been proposed as analytic tools, their utility in clinical practice may be limited. Firstly, due to its popularity in the lay press, the golden ratio has been inconsistently applied to a wide range of facial ratios, which may undermine confidence in its representation as truth rather than coincidence. Secondly, although some authors have found validity of the golden decagon mask in representing unified ratios of attractiveness, others have asserted that it characterizes a masculinized white female and fails to account for ethnic differences.^15-19

Age-Related Changes

In addition to the facial proportions guided by genetics, several changes occur with increased age. Over the course of a lifetime, predictable patterns emerge in the dimensions of the skin, soft tissue, and bone. These alterations in structural proportions may ultimately lead to an unevenness in facial aesthetics.

In skeletal structure, gradual bone resorption and expansion causes a reduction in facial height as well as an increase in facial width and depth.²⁰ Fat atrophy and hypertrophy affect soft tissue proportions, visualized as hollowing at the temples, cheeks, and around the eyes, along with fullness in the submental region and jowls.²¹ Finally, decreases in skin elasticity and collagen exacerbate the appearance of rhytides and sagging. In older patients who desire a more youthful appearance, various applications of dermal fillers, fat grafting, liposuction, and skin tightening techniques can help to mitigate these changes.

Conclusion

Improving facial aesthetics relies on an understanding of the norms of facial proportions. Although cosmetic interventions commonly are advertised or described based on a single anatomical unit, it is important to appreciate the relationships between facial structures. Most notably, clinicians should be mindful of facial ratios when considering the introduction of filler materials or implants. Augmentation procedures at the temples, zygomatic arch, jaw, chin, and lips all have the possibility to alter facial ratios. Changes should therefore be considered in the context of improving overall facial harmony, with the clinician remaining cognizant of the ideal vertical and horizontal divisions of the face. Understanding such concepts and communicating them to patients can help in appropriately addressing all target areas, thereby leading to greater patient satisfaction.

Several concepts of ideal aesthetic measurements can be traced back to ancient Greek and European Renaissance art. In examining canons of beauty, these classical ideals often are compared to modern-day standards, allowing clinicians to delineate the parameters of an attractive facial appearance and facilitate the planning of cosmetic procedures.

Given the growing number of available cosmetic interventions, dermatologists have a powerful ability to modify facial proportions; however, changes to individual structures should be made with a mindful approach to improving overall facial harmony. This article reviews the established parameters of facial beauty to assist the clinician in enhancing cosmetic outcomes.

Canons of Facial Aesthetics

Horizontal Thirds
In his writings on human anatomy, Leonardo da Vinci described dividing the face into equal thirds (Figure 1). The upper third measures from the trichion (the midline point of the normal hairline) to the glabella (the smooth prominence between the eyebrows). The middle third measures from the glabella to the subnasale (the midline point where the nasal septum meets the upper lip). The lower third measures from the subnasale to the menton (the most inferior point of the chin).¹

Although the validity of the canon is intended to apply across race and gender, these proportions may vary by ethnicity (Table). In white individuals, the middle third of the face tends to be shorter than the upper and lower thirds.² This same relationship has been observed in black males.³ In Chinese females, the upper third commonly is shorter than the middle and lower thirds, correlating with a less prominent forehead. In contrast, black females tend to have a relatively longer upper third.⁴

The relationship between modern perceptions of attractiveness and the neoclassical norm of equal thirds remains a topic of interest. Milutinovic et al¹ examined facial thirds in white female celebrities from beauty and fashion magazines and compared them to a group of anonymous white females from the general population. The group of anonymous females showed statistically significant (P<.05) differences between the sizes of the 3 facial segments, whereas the group of celebrity faces demonstrated uniformity between the facial thirds.¹

The lower face can itself be divided into thirds, with the upper third measured from the subnasale to the stomion (the midline point of the oral fissure when the lips are closed), and the lower two-thirds measured from the stomion to the menton (Figure 1). Mommaerts and Moerenhout⁵ examined photographs of 105 attractive celebrity faces and compared their proportions to those of classical sculptures of gods and goddesses (antique faces). The authors identified an upper one-third to lower two-thirds ratio of 69.8% in celebrity females and 69.1% in celebrity males; these ratios were not significantly different from the 72.4% seen in antique females and 73.1% in antique males. The authors concluded that a 30% upper lip to 70% lower lip-chin proportion may be the most appropriate to describe contemporary standards.⁵

Vertical Fifths
In the vertical dimension, the neoclassical canon of facial proportions divides the face into equal fifths (Figure 2).⁶ The 2 most lateral fifths are measured from the lateral helix of each ear to the exocanthus of each eye. The eye fissure lengths (measured between the endocanthion and exocanthion of each eye) represent one-fifth. The middle fifth is measured between the medial canthi of both eyes (endocanthion to endocanthion). This distance is equal to the width of the nose, as measured between both alae. Finally, the width of the mouth represents 1.5-times the width of the nose. These ratios of the vertical fifths apply to both males and females.⁶

Anthropometric studies have examined deviations from the neoclassical canon according to ethnicity. Wang et al⁷ compared the measurements of North American white and Han Chinese patients to these standards. White patients demonstrated a greater ratio of mouth width to nose width relative to the canon. In contrast, Han Chinese patients demonstrated a relatively wider nose and narrower mouth.⁷

In black individuals, it has been observed that the dimensions of most facial segments correspond to the neoclassical standards; however, nose width is relatively wider in black individuals relative to the canon as well as relative to white individuals.⁸

Milutinovic et al¹ also compared vertical fifths between white celebrities and anonymous females. In the anonymous female group, statistically significant (P<.05) variations were found between the sizes of the different facial components. In contrast, the celebrity female group showed balance between the widths of vertical fifths.¹

Lips
In the lower facial third, the lips represent a key element of attractiveness. Recently, lip augmentation, aimed at creating fuller and plumper lips, has dominated the popular culture and social media landscape.⁹ Although the aesthetic ideal of lips continues to evolve over time, recent studies have aimed at quantifying modern notions of attractive lip appearance.

Popenko et al¹⁰ examined lip measurements using computer-generated images of white women with different variations of lip sizes and lower face proportions. Computer-generated faces were graded on attractiveness by more than 400 individuals from focus groups. An upper lip to lower lip ratio of 1:2 was judged to be the most attractive, while a ratio of 2:1 was judged to be the least attractive. Results also showed that the surface area of the most attractive lips comprised roughly 10% of the lower third of the face.¹⁰

Penna et al¹¹ analyzed various parameters of the lips and lower facial third using photographs of 176 white males and females that were judged on attractiveness by 250 volunteer evaluators. Faces were graded on a scale from 1 (absolutely attractive) to 7 (absolutely unattractive). Attractive males and females (grades 1 and 2) both demonstrated an average ratio of upper vermilion height to nose-mouth distance (measured from the subnasalae to the lower edge of the upper vermilion border) of 0.28, which was significantly greater than the average ratio observed in less attractive individuals (grades 6 or 7)(P<.05). In addition, attractive males and females demonstrated a ratio of upper vermilion height to nose-chin distance (measured from the subnasalae to the menton) of 0.09, which again was larger than the average ratio seen in less attractive individuals. Figure 3 demonstrates an aesthetic ideal of the lips derived from these 2 studies, though consideration should be given to the fact that these studies were based in white populations.

Golden Ratio
The golden ratio, also known as Phi, can be observed in nature, art, and architecture. Approximately equal to 1.618, the golden ratio also has been identified as a possible marker of beauty in the human face and has garnered attention in the lay press. The ratio has been applied to several proportions and structures in the face, such as the ratio of mouth width to nose width or the ratio of tooth height to tooth width, with investigation providing varying levels of validation about whether these ratios truly correlate with perceptions of beauty.¹² Swift and Remington¹³ advocated for application of the golden ratio toward a comprehensive set of facial proportions. Marquardt¹⁴ used the golden ratio to create a 3-dimensional representation of an idealized face, known as the golden decagon mask. Although the golden ratio and the golden decagon mask have been proposed as analytic tools, their utility in clinical practice may be limited. Firstly, due to its popularity in the lay press, the golden ratio has been inconsistently applied to a wide range of facial ratios, which may undermine confidence in its representation as truth rather than coincidence. Secondly, although some authors have found validity of the golden decagon mask in representing unified ratios of attractiveness, others have asserted that it characterizes a masculinized white female and fails to account for ethnic differences.^15-19

Age-Related Changes

In addition to the facial proportions guided by genetics, several changes occur with increased age. Over the course of a lifetime, predictable patterns emerge in the dimensions of the skin, soft tissue, and bone. These alterations in structural proportions may ultimately lead to an unevenness in facial aesthetics.

In skeletal structure, gradual bone resorption and expansion causes a reduction in facial height as well as an increase in facial width and depth.²⁰ Fat atrophy and hypertrophy affect soft tissue proportions, visualized as hollowing at the temples, cheeks, and around the eyes, along with fullness in the submental region and jowls.²¹ Finally, decreases in skin elasticity and collagen exacerbate the appearance of rhytides and sagging. In older patients who desire a more youthful appearance, various applications of dermal fillers, fat grafting, liposuction, and skin tightening techniques can help to mitigate these changes.

Conclusion

Improving facial aesthetics relies on an understanding of the norms of facial proportions. Although cosmetic interventions commonly are advertised or described based on a single anatomical unit, it is important to appreciate the relationships between facial structures. Most notably, clinicians should be mindful of facial ratios when considering the introduction of filler materials or implants. Augmentation procedures at the temples, zygomatic arch, jaw, chin, and lips all have the possibility to alter facial ratios. Changes should therefore be considered in the context of improving overall facial harmony, with the clinician remaining cognizant of the ideal vertical and horizontal divisions of the face. Understanding such concepts and communicating them to patients can help in appropriately addressing all target areas, thereby leading to greater patient satisfaction.

Several concepts of ideal aesthetic measurements can be traced back to ancient Greek and European Renaissance art. In examining canons of beauty, these classical ideals often are compared to modern-day standards, allowing clinicians to delineate the parameters of an attractive facial appearance and facilitate the planning of cosmetic procedures.

Given the growing number of available cosmetic interventions, dermatologists have a powerful ability to modify facial proportions; however, changes to individual structures should be made with a mindful approach to improving overall facial harmony. This article reviews the established parameters of facial beauty to assist the clinician in enhancing cosmetic outcomes.

Canons of Facial Aesthetics

Horizontal Thirds
In his writings on human anatomy, Leonardo da Vinci described dividing the face into equal thirds (Figure 1). The upper third measures from the trichion (the midline point of the normal hairline) to the glabella (the smooth prominence between the eyebrows). The middle third measures from the glabella to the subnasale (the midline point where the nasal septum meets the upper lip). The lower third measures from the subnasale to the menton (the most inferior point of the chin).¹

Although the validity of the canon is intended to apply across race and gender, these proportions may vary by ethnicity (Table). In white individuals, the middle third of the face tends to be shorter than the upper and lower thirds.² This same relationship has been observed in black males.³ In Chinese females, the upper third commonly is shorter than the middle and lower thirds, correlating with a less prominent forehead. In contrast, black females tend to have a relatively longer upper third.⁴

The relationship between modern perceptions of attractiveness and the neoclassical norm of equal thirds remains a topic of interest. Milutinovic et al¹ examined facial thirds in white female celebrities from beauty and fashion magazines and compared them to a group of anonymous white females from the general population. The group of anonymous females showed statistically significant (P<.05) differences between the sizes of the 3 facial segments, whereas the group of celebrity faces demonstrated uniformity between the facial thirds.¹

The lower face can itself be divided into thirds, with the upper third measured from the subnasale to the stomion (the midline point of the oral fissure when the lips are closed), and the lower two-thirds measured from the stomion to the menton (Figure 1). Mommaerts and Moerenhout⁵ examined photographs of 105 attractive celebrity faces and compared their proportions to those of classical sculptures of gods and goddesses (antique faces). The authors identified an upper one-third to lower two-thirds ratio of 69.8% in celebrity females and 69.1% in celebrity males; these ratios were not significantly different from the 72.4% seen in antique females and 73.1% in antique males. The authors concluded that a 30% upper lip to 70% lower lip-chin proportion may be the most appropriate to describe contemporary standards.⁵

Vertical Fifths
In the vertical dimension, the neoclassical canon of facial proportions divides the face into equal fifths (Figure 2).⁶ The 2 most lateral fifths are measured from the lateral helix of each ear to the exocanthus of each eye. The eye fissure lengths (measured between the endocanthion and exocanthion of each eye) represent one-fifth. The middle fifth is measured between the medial canthi of both eyes (endocanthion to endocanthion). This distance is equal to the width of the nose, as measured between both alae. Finally, the width of the mouth represents 1.5-times the width of the nose. These ratios of the vertical fifths apply to both males and females.⁶

Anthropometric studies have examined deviations from the neoclassical canon according to ethnicity. Wang et al⁷ compared the measurements of North American white and Han Chinese patients to these standards. White patients demonstrated a greater ratio of mouth width to nose width relative to the canon. In contrast, Han Chinese patients demonstrated a relatively wider nose and narrower mouth.⁷

In black individuals, it has been observed that the dimensions of most facial segments correspond to the neoclassical standards; however, nose width is relatively wider in black individuals relative to the canon as well as relative to white individuals.⁸

Milutinovic et al¹ also compared vertical fifths between white celebrities and anonymous females. In the anonymous female group, statistically significant (P<.05) variations were found between the sizes of the different facial components. In contrast, the celebrity female group showed balance between the widths of vertical fifths.¹

Lips
In the lower facial third, the lips represent a key element of attractiveness. Recently, lip augmentation, aimed at creating fuller and plumper lips, has dominated the popular culture and social media landscape.⁹ Although the aesthetic ideal of lips continues to evolve over time, recent studies have aimed at quantifying modern notions of attractive lip appearance.

Popenko et al¹⁰ examined lip measurements using computer-generated images of white women with different variations of lip sizes and lower face proportions. Computer-generated faces were graded on attractiveness by more than 400 individuals from focus groups. An upper lip to lower lip ratio of 1:2 was judged to be the most attractive, while a ratio of 2:1 was judged to be the least attractive. Results also showed that the surface area of the most attractive lips comprised roughly 10% of the lower third of the face.¹⁰

Penna et al¹¹ analyzed various parameters of the lips and lower facial third using photographs of 176 white males and females that were judged on attractiveness by 250 volunteer evaluators. Faces were graded on a scale from 1 (absolutely attractive) to 7 (absolutely unattractive). Attractive males and females (grades 1 and 2) both demonstrated an average ratio of upper vermilion height to nose-mouth distance (measured from the subnasalae to the lower edge of the upper vermilion border) of 0.28, which was significantly greater than the average ratio observed in less attractive individuals (grades 6 or 7)(P<.05). In addition, attractive males and females demonstrated a ratio of upper vermilion height to nose-chin distance (measured from the subnasalae to the menton) of 0.09, which again was larger than the average ratio seen in less attractive individuals. Figure 3 demonstrates an aesthetic ideal of the lips derived from these 2 studies, though consideration should be given to the fact that these studies were based in white populations.

Golden Ratio
The golden ratio, also known as Phi, can be observed in nature, art, and architecture. Approximately equal to 1.618, the golden ratio also has been identified as a possible marker of beauty in the human face and has garnered attention in the lay press. The ratio has been applied to several proportions and structures in the face, such as the ratio of mouth width to nose width or the ratio of tooth height to tooth width, with investigation providing varying levels of validation about whether these ratios truly correlate with perceptions of beauty.¹² Swift and Remington¹³ advocated for application of the golden ratio toward a comprehensive set of facial proportions. Marquardt¹⁴ used the golden ratio to create a 3-dimensional representation of an idealized face, known as the golden decagon mask. Although the golden ratio and the golden decagon mask have been proposed as analytic tools, their utility in clinical practice may be limited. Firstly, due to its popularity in the lay press, the golden ratio has been inconsistently applied to a wide range of facial ratios, which may undermine confidence in its representation as truth rather than coincidence. Secondly, although some authors have found validity of the golden decagon mask in representing unified ratios of attractiveness, others have asserted that it characterizes a masculinized white female and fails to account for ethnic differences.^15-19

Age-Related Changes

In addition to the facial proportions guided by genetics, several changes occur with increased age. Over the course of a lifetime, predictable patterns emerge in the dimensions of the skin, soft tissue, and bone. These alterations in structural proportions may ultimately lead to an unevenness in facial aesthetics.

In skeletal structure, gradual bone resorption and expansion causes a reduction in facial height as well as an increase in facial width and depth.²⁰ Fat atrophy and hypertrophy affect soft tissue proportions, visualized as hollowing at the temples, cheeks, and around the eyes, along with fullness in the submental region and jowls.²¹ Finally, decreases in skin elasticity and collagen exacerbate the appearance of rhytides and sagging. In older patients who desire a more youthful appearance, various applications of dermal fillers, fat grafting, liposuction, and skin tightening techniques can help to mitigate these changes.

Conclusion

Improving facial aesthetics relies on an understanding of the norms of facial proportions. Although cosmetic interventions commonly are advertised or described based on a single anatomical unit, it is important to appreciate the relationships between facial structures. Most notably, clinicians should be mindful of facial ratios when considering the introduction of filler materials or implants. Augmentation procedures at the temples, zygomatic arch, jaw, chin, and lips all have the possibility to alter facial ratios. Changes should therefore be considered in the context of improving overall facial harmony, with the clinician remaining cognizant of the ideal vertical and horizontal divisions of the face. Understanding such concepts and communicating them to patients can help in appropriately addressing all target areas, thereby leading to greater patient satisfaction.

Local anesthesia is a central component of successful interventions in cosmetic dermatology. The number of anesthetic medications and administration techniques has grown in recent years as outpatient cosmetic procedures continue to expand. Pain is a common barrier to cosmetic procedures, and alleviating the fear of painful interventions is critical to patient satisfaction and future visits. To accommodate a multitude of cosmetic interventions, it is important for clinicians to be well versed in applications of topical and regional anesthesia. In this article, we review pain management strategies for use in cosmetic practice.

Local Anesthetics

The sensation of pain is carried to the central nervous system by unmyelinated C nerve fibers. Local anesthetics (LAs) act by blocking fast voltage-gated sodium channels in the cell membrane of the nerve, thereby inhibiting downstream propagation of an action potential and the transmission of painful stimuli.¹ The chemical structure of LAs is fundamental to their mechanism of action and metabolism. Local anesthetics contain a lipophilic aromatic group, an intermediate chain, and a hydrophilic amine group. Broadly, agents are classified as amides or esters depending on the chemical group attached to the intermediate chain.² Amides (eg, lidocaine, bupivacaine, articaine, mepivacaine, prilocaine, levobupivacaine) are metabolized by the hepatic system; esters (eg, procaine, proparacaine, benzocaine, chlorprocaine, tetracaine, cocaine) are metabolized by plasma cholinesterase, which produces para-aminobenzoic acid, a potentially dangerous metabolite that has been implicated in allergic reactions.³

Lidocaine is the most prevalent LA used in dermatology practices. Importantly, lidocaine is a class IB antiarrhythmic agent used in cardiology to treat ventricular arrhythmias.⁴ As an anesthetic, a maximum dose of 4.5 mg/kg can be administered, increasing to 7.0 mg/kg when mixed with epinephrine; with higher doses, there is a risk for central nervous system and cardiovascular toxicity.⁵ Initial symptoms of lidocaine toxicity include dizziness, tinnitus, circumoral paresthesia, blurred vision, and a metallic taste in the mouth.⁶ Systemic absorption of topical anesthetics is heightened across mucosal membranes, and care should be taken when applying over large surface areas.

Allergic reactions to LAs may be local or less frequently systemic. It is important to note that LAs tend to show cross-reactivity within their class rather than across different classes.⁷ Reactions can be classified as type I or type IV. Type I (IgE-mediated) reactions evolve in minutes to hours, affecting the skin and possibly leading to respiratory and circulatory collapse. Delayed reactions to LAs have increased in recent years, with type IV contact allergy most frequently found in connection with benzocaine and lidocaine.⁸

Topical Anesthesia

Topical anesthetics are effective and easy to use and are particularly valuable in patients with needle phobia. In certain cases, these medications may be applied by the patient prior to arrival, thereby reducing visit time. Topical agents act on nerve fibers running through the dermis; therefore, efficacy is dependent on successful penetration through the stratum corneum and viable epidermis. To enhance absorption, agents may be applied under an occlusive dressing.

Topical anesthetics are most commonly used for injectable fillers, ablative and nonablative laser resurfacing, laser hair removal, and tattoo removal. The eutectic mixture of 2.5% lidocaine and 2.5% prilocaine as well as topical 4% or 5% lidocaine are the most commonly used US Food and Drug Administration–approved products for topical anesthesia. In addition, several compounded pharmacy products are available.

After 60 minutes of application of the eutectic mixture of 2.5% lidocaine and 2.5% prilocaine, a 3-mm depth of analgesia is reached, and after 120 minutes, a 4.5-mm depth is reached.⁹ It elicits a biphasic vascular response of vasoconstriction and blanching followed by vasodilation and erythema.¹⁰ Most adverse events are mild and transient, but allergic contact dermatitis and contact urticaria have been reported.^11-13 In older children and adults, the maximum application area is 200 cm², with a maximum dose of 20 g used for no longer than 4 hours.

The 4% or 5% lidocaine cream uses a liposomal delivery system, which is designed to improve cutaneous penetration and has been shown to provide longer durations of anesthesia than nonliposomal lidocaine preparations.¹⁴ Application should be performed 30 to 60 minutes prior to a procedure. In a study comparing the eutectic mixture of 2.5% lidocaine and 2.5% prilocaine versus lidocaine cream 5% for pain control during laser hair removal with a 1064-nm Nd:YAG laser, no significant differences were found.¹⁵ The maximum application area is 100 cm² in children weighing less than 20 kg. A study of healthy adults demonstrated safety with the use of 30 to 60 g of occluded liposomal lidocaine cream 4%.¹⁶

In addition to US Food and Drug Administration–approved products, several compounded pharmacy products are available for topical anesthesia. These formulations include benzocaine-lidocaine-tetracaine gel, tetracaine-adrenaline-cocaine solution, and lidocaine-epinephrine-tetracaine solution. A triple-anesthetic gel, benzocaine-lidocaine-tetracaine is widely used in cosmetic practice. The product has been shown to provide adequate anesthesia for laser resurfacing after 20 minutes without occlusion.¹⁷ Of note, compounded anesthetics lack standardization, and different pharmacies may follow their own individual protocols.

Regional Anesthesia

Regional nerve blockade is a useful option for more widespread or complex interventions. Using regional nerve blockade, effective analgesia can be delivered to a target area while avoiding the toxicity and pain associated with numerous anesthetic infiltrations. In addition, there is no distortion of the tissue architecture, allowing for improved visual evaluation during the procedure. Recently, hyaluronic acid fillers have been compounded with lidocaine as a means of reducing procedural pain.

Blocks for Dermal Fillers

Forehead
For dermal filler injections of the glabellar and frontalis lines, anesthesia of the forehead may be desired. The supraorbital and supratrochlear nerves supply this area. The supraorbital nerve can be injected at the supraorbital notch, which is measured roughly 2.7 cm from the glabella. The orbital rim should be palpated with the nondominant hand, and 1 to 2 mL of anesthetic should be injected just below the rim (Figure 1). The supratrochlear nerve is located roughly 1.7 cm from the midline and can be similarly injected under the orbital rim with 1 to 2 mL of anesthetic (Figure 1).

Lateral Temple Region
Anesthesia of the zygomaticotemporal nerve can be used to reduce pain from dermal filler injections of the lateral canthal and temporal areas. The nerve is identified by first palpating the zygomaticofrontal suture. A long needle is then inserted posteriorly, immediately behind the concave surface of the lateral orbital rim, and 1 to 2 mL of anesthetic is injected (Figure 1).

Malar Region
Blockade of the zygomaticofacial nerve is commonly performed in conjunction with the zygomaticotemporal nerve and provides anesthesia to the malar region for cheek augmentation procedures. To identify the target area, the junction of the lateral and inferior orbital rim should be palpated. With the needle placed just lateral to this point, 1 to 2 mL of anesthetic is injected (Figure 1).

Blocks for Perioral Fillers

Upper Lips/Nasolabial Folds
Bilateral blockade of the infraorbital nerves provides anesthesia to the upper lip and nasolabial folds prior to filler injections. The infraorbital nerve can be targeted via an intraoral route where it exits the maxilla at the infraorbital foramen. The nerve is anesthetized by palpating the infraorbital ridge and injecting 3 to 5 mL of anesthetic roughly 1 cm below this point on the vertical axis of the midpupillary line (Figure 1). The external nasal nerve, thought to be a branch of cranial nerve V, also may be targeted if there is inadequate anesthesia from the infraorbital block. This nerve is reached by injecting at the osseocartilaginous junction of the nasal bones (Figure 1).

Lower Lips
Blockade of the mental nerve provides anesthesia to the lower lips for augmentation procedures. The mental nerve can be targeted on each side at the mental foramen, which is located below the root of the lower second premolar. Aiming roughly 1 cm below the gumline, 3 to 5 mL of anesthetic is injected intraorally (Figure 1). A transcutaneous approach toward the same target also is possible, though this technique risks visible bruising. Alternatively, the upper or lower lips can be anesthetized using 4 to 5 submucosal injections at evenly spaced intervals between the canine teeth.¹⁸

Blocks for Palmoplantar Hyperhidrosis

The treatment of palmoplantar hyperhidrosis benefits from regional blocks. Botulinum toxin has been well established as an effective therapy for the condition.^19-21 Given the sensitivity of palmoplantar sites, it is valuable to achieve effective analgesia of the region prior to dermal injections of botulinum toxin.

Wrists
Sensory innervation of the palm is provided by the median, ulnar, and radial nerves (Figure 2A). At the wrist, the median nerve lies between the tendons of the flexor carpi radialis muscle and the palmaris longus muscle. To facilitate identification of the palmaris longus muscle, instruct the patient to oppose the thumb and little finger while flexing the wrist. The needle should be inserted between the 2 tendons, just proximal to the wrist creases (Figure 2B). Once the fascia is pierced, 3 to 5 mL of anesthetic is injected.

The ulnar nerve is anesthetized between the ulnar artery and the flexor carpi ulnaris muscle. The artery is identified by palpation, and special care should be taken to avoid intra-arterial injection. The needle is directed toward the radial styloid, and 3 to 5 mL of anesthetic is injected roughly 1 cm proximal to the wrist crease (Figure 2B).

Anesthesia of the radial nerve can be considered a field block given the numerous small branches that supply the hand. These branches are reached by injecting anesthetic roughly 2 to 3 cm proximal to the radial styloid with the needle aimed medially and extending the injection dorsally (Figure 2B). A total of 4 to 6 mL of anesthetic is used.

Ankles
An ankle block provides anesthesia to the dorsal and plantar surfaces of the foot.²² The region is supplied by the superficial peroneal nerve, deep peroneal nerve, sural nerve, saphenous nerve, and branches of the posterior tibial nerve (Figure 3A).

To anesthetize the deep peroneal nerve, the extensor hallucis longus tendon is first identified on the anterior surface of the ankle through dorsiflexion of the toes; the dorsalis pedis artery runs in close proximity. The injection should be placed lateral to the tendon and artery (Figure 3B). The needle should be inserted until bone is reached, withdrawn slightly, and then 3 to 5 mL of anesthetic should be injected. To block the saphenous nerve, the needle can then be directed superficially toward the medial malleolus, and 3 to 5 mL should be injected in a subcutaneous wheal (Figure 3C). To block the superficial peroneal nerve, the needle should then be directed toward the lateral malleolus, and 3 to 5 mL should be injected in a subcutaneous wheal (Figure 3C).

The posterior tibial nerve is located posterior to the medial malleolus. The dorsalis pedis artery can be palpated near this location. The needle should be inserted posterior to the artery, extending until bone is reached (Figure 3C). The needle is then withdrawn slightly, and 3 to 5 mL of anesthetic is injected. Finally, the sural nerve is anesthetized between the Achilles tendon and the lateral malleolus, using 5 mL of anesthetic to raise a subcutaneous wheal (Figure 3C).

Conclusion

Proper pain management is integral to ensuring a positive experience for cosmetic patients. Enhanced knowledge of local anesthetic techniques allows the clinician to provide for a variety of procedural indications and patient preferences. As anesthetic strategies are continually evolving, it is important for practitioners to remain informed of these developments.

Local anesthesia is a central component of successful interventions in cosmetic dermatology. The number of anesthetic medications and administration techniques has grown in recent years as outpatient cosmetic procedures continue to expand. Pain is a common barrier to cosmetic procedures, and alleviating the fear of painful interventions is critical to patient satisfaction and future visits. To accommodate a multitude of cosmetic interventions, it is important for clinicians to be well versed in applications of topical and regional anesthesia. In this article, we review pain management strategies for use in cosmetic practice.

Local Anesthetics

The sensation of pain is carried to the central nervous system by unmyelinated C nerve fibers. Local anesthetics (LAs) act by blocking fast voltage-gated sodium channels in the cell membrane of the nerve, thereby inhibiting downstream propagation of an action potential and the transmission of painful stimuli.¹ The chemical structure of LAs is fundamental to their mechanism of action and metabolism. Local anesthetics contain a lipophilic aromatic group, an intermediate chain, and a hydrophilic amine group. Broadly, agents are classified as amides or esters depending on the chemical group attached to the intermediate chain.² Amides (eg, lidocaine, bupivacaine, articaine, mepivacaine, prilocaine, levobupivacaine) are metabolized by the hepatic system; esters (eg, procaine, proparacaine, benzocaine, chlorprocaine, tetracaine, cocaine) are metabolized by plasma cholinesterase, which produces para-aminobenzoic acid, a potentially dangerous metabolite that has been implicated in allergic reactions.³

Lidocaine is the most prevalent LA used in dermatology practices. Importantly, lidocaine is a class IB antiarrhythmic agent used in cardiology to treat ventricular arrhythmias.⁴ As an anesthetic, a maximum dose of 4.5 mg/kg can be administered, increasing to 7.0 mg/kg when mixed with epinephrine; with higher doses, there is a risk for central nervous system and cardiovascular toxicity.⁵ Initial symptoms of lidocaine toxicity include dizziness, tinnitus, circumoral paresthesia, blurred vision, and a metallic taste in the mouth.⁶ Systemic absorption of topical anesthetics is heightened across mucosal membranes, and care should be taken when applying over large surface areas.

Allergic reactions to LAs may be local or less frequently systemic. It is important to note that LAs tend to show cross-reactivity within their class rather than across different classes.⁷ Reactions can be classified as type I or type IV. Type I (IgE-mediated) reactions evolve in minutes to hours, affecting the skin and possibly leading to respiratory and circulatory collapse. Delayed reactions to LAs have increased in recent years, with type IV contact allergy most frequently found in connection with benzocaine and lidocaine.⁸

Topical Anesthesia

Topical anesthetics are effective and easy to use and are particularly valuable in patients with needle phobia. In certain cases, these medications may be applied by the patient prior to arrival, thereby reducing visit time. Topical agents act on nerve fibers running through the dermis; therefore, efficacy is dependent on successful penetration through the stratum corneum and viable epidermis. To enhance absorption, agents may be applied under an occlusive dressing.

Topical anesthetics are most commonly used for injectable fillers, ablative and nonablative laser resurfacing, laser hair removal, and tattoo removal. The eutectic mixture of 2.5% lidocaine and 2.5% prilocaine as well as topical 4% or 5% lidocaine are the most commonly used US Food and Drug Administration–approved products for topical anesthesia. In addition, several compounded pharmacy products are available.

After 60 minutes of application of the eutectic mixture of 2.5% lidocaine and 2.5% prilocaine, a 3-mm depth of analgesia is reached, and after 120 minutes, a 4.5-mm depth is reached.⁹ It elicits a biphasic vascular response of vasoconstriction and blanching followed by vasodilation and erythema.¹⁰ Most adverse events are mild and transient, but allergic contact dermatitis and contact urticaria have been reported.^11-13 In older children and adults, the maximum application area is 200 cm², with a maximum dose of 20 g used for no longer than 4 hours.

The 4% or 5% lidocaine cream uses a liposomal delivery system, which is designed to improve cutaneous penetration and has been shown to provide longer durations of anesthesia than nonliposomal lidocaine preparations.¹⁴ Application should be performed 30 to 60 minutes prior to a procedure. In a study comparing the eutectic mixture of 2.5% lidocaine and 2.5% prilocaine versus lidocaine cream 5% for pain control during laser hair removal with a 1064-nm Nd:YAG laser, no significant differences were found.¹⁵ The maximum application area is 100 cm² in children weighing less than 20 kg. A study of healthy adults demonstrated safety with the use of 30 to 60 g of occluded liposomal lidocaine cream 4%.¹⁶

In addition to US Food and Drug Administration–approved products, several compounded pharmacy products are available for topical anesthesia. These formulations include benzocaine-lidocaine-tetracaine gel, tetracaine-adrenaline-cocaine solution, and lidocaine-epinephrine-tetracaine solution. A triple-anesthetic gel, benzocaine-lidocaine-tetracaine is widely used in cosmetic practice. The product has been shown to provide adequate anesthesia for laser resurfacing after 20 minutes without occlusion.¹⁷ Of note, compounded anesthetics lack standardization, and different pharmacies may follow their own individual protocols.

Regional Anesthesia

Regional nerve blockade is a useful option for more widespread or complex interventions. Using regional nerve blockade, effective analgesia can be delivered to a target area while avoiding the toxicity and pain associated with numerous anesthetic infiltrations. In addition, there is no distortion of the tissue architecture, allowing for improved visual evaluation during the procedure. Recently, hyaluronic acid fillers have been compounded with lidocaine as a means of reducing procedural pain.

Blocks for Dermal Fillers

Forehead
For dermal filler injections of the glabellar and frontalis lines, anesthesia of the forehead may be desired. The supraorbital and supratrochlear nerves supply this area. The supraorbital nerve can be injected at the supraorbital notch, which is measured roughly 2.7 cm from the glabella. The orbital rim should be palpated with the nondominant hand, and 1 to 2 mL of anesthetic should be injected just below the rim (Figure 1). The supratrochlear nerve is located roughly 1.7 cm from the midline and can be similarly injected under the orbital rim with 1 to 2 mL of anesthetic (Figure 1).

Lateral Temple Region
Anesthesia of the zygomaticotemporal nerve can be used to reduce pain from dermal filler injections of the lateral canthal and temporal areas. The nerve is identified by first palpating the zygomaticofrontal suture. A long needle is then inserted posteriorly, immediately behind the concave surface of the lateral orbital rim, and 1 to 2 mL of anesthetic is injected (Figure 1).

Malar Region
Blockade of the zygomaticofacial nerve is commonly performed in conjunction with the zygomaticotemporal nerve and provides anesthesia to the malar region for cheek augmentation procedures. To identify the target area, the junction of the lateral and inferior orbital rim should be palpated. With the needle placed just lateral to this point, 1 to 2 mL of anesthetic is injected (Figure 1).

Blocks for Perioral Fillers

Upper Lips/Nasolabial Folds
Bilateral blockade of the infraorbital nerves provides anesthesia to the upper lip and nasolabial folds prior to filler injections. The infraorbital nerve can be targeted via an intraoral route where it exits the maxilla at the infraorbital foramen. The nerve is anesthetized by palpating the infraorbital ridge and injecting 3 to 5 mL of anesthetic roughly 1 cm below this point on the vertical axis of the midpupillary line (Figure 1). The external nasal nerve, thought to be a branch of cranial nerve V, also may be targeted if there is inadequate anesthesia from the infraorbital block. This nerve is reached by injecting at the osseocartilaginous junction of the nasal bones (Figure 1).

Lower Lips
Blockade of the mental nerve provides anesthesia to the lower lips for augmentation procedures. The mental nerve can be targeted on each side at the mental foramen, which is located below the root of the lower second premolar. Aiming roughly 1 cm below the gumline, 3 to 5 mL of anesthetic is injected intraorally (Figure 1). A transcutaneous approach toward the same target also is possible, though this technique risks visible bruising. Alternatively, the upper or lower lips can be anesthetized using 4 to 5 submucosal injections at evenly spaced intervals between the canine teeth.¹⁸

Blocks for Palmoplantar Hyperhidrosis

The treatment of palmoplantar hyperhidrosis benefits from regional blocks. Botulinum toxin has been well established as an effective therapy for the condition.^19-21 Given the sensitivity of palmoplantar sites, it is valuable to achieve effective analgesia of the region prior to dermal injections of botulinum toxin.

Wrists
Sensory innervation of the palm is provided by the median, ulnar, and radial nerves (Figure 2A). At the wrist, the median nerve lies between the tendons of the flexor carpi radialis muscle and the palmaris longus muscle. To facilitate identification of the palmaris longus muscle, instruct the patient to oppose the thumb and little finger while flexing the wrist. The needle should be inserted between the 2 tendons, just proximal to the wrist creases (Figure 2B). Once the fascia is pierced, 3 to 5 mL of anesthetic is injected.

The ulnar nerve is anesthetized between the ulnar artery and the flexor carpi ulnaris muscle. The artery is identified by palpation, and special care should be taken to avoid intra-arterial injection. The needle is directed toward the radial styloid, and 3 to 5 mL of anesthetic is injected roughly 1 cm proximal to the wrist crease (Figure 2B).

Anesthesia of the radial nerve can be considered a field block given the numerous small branches that supply the hand. These branches are reached by injecting anesthetic roughly 2 to 3 cm proximal to the radial styloid with the needle aimed medially and extending the injection dorsally (Figure 2B). A total of 4 to 6 mL of anesthetic is used.

Ankles
An ankle block provides anesthesia to the dorsal and plantar surfaces of the foot.²² The region is supplied by the superficial peroneal nerve, deep peroneal nerve, sural nerve, saphenous nerve, and branches of the posterior tibial nerve (Figure 3A).

To anesthetize the deep peroneal nerve, the extensor hallucis longus tendon is first identified on the anterior surface of the ankle through dorsiflexion of the toes; the dorsalis pedis artery runs in close proximity. The injection should be placed lateral to the tendon and artery (Figure 3B). The needle should be inserted until bone is reached, withdrawn slightly, and then 3 to 5 mL of anesthetic should be injected. To block the saphenous nerve, the needle can then be directed superficially toward the medial malleolus, and 3 to 5 mL should be injected in a subcutaneous wheal (Figure 3C). To block the superficial peroneal nerve, the needle should then be directed toward the lateral malleolus, and 3 to 5 mL should be injected in a subcutaneous wheal (Figure 3C).

The posterior tibial nerve is located posterior to the medial malleolus. The dorsalis pedis artery can be palpated near this location. The needle should be inserted posterior to the artery, extending until bone is reached (Figure 3C). The needle is then withdrawn slightly, and 3 to 5 mL of anesthetic is injected. Finally, the sural nerve is anesthetized between the Achilles tendon and the lateral malleolus, using 5 mL of anesthetic to raise a subcutaneous wheal (Figure 3C).

Conclusion

Proper pain management is integral to ensuring a positive experience for cosmetic patients. Enhanced knowledge of local anesthetic techniques allows the clinician to provide for a variety of procedural indications and patient preferences. As anesthetic strategies are continually evolving, it is important for practitioners to remain informed of these developments.

Local anesthesia is a central component of successful interventions in cosmetic dermatology. The number of anesthetic medications and administration techniques has grown in recent years as outpatient cosmetic procedures continue to expand. Pain is a common barrier to cosmetic procedures, and alleviating the fear of painful interventions is critical to patient satisfaction and future visits. To accommodate a multitude of cosmetic interventions, it is important for clinicians to be well versed in applications of topical and regional anesthesia. In this article, we review pain management strategies for use in cosmetic practice.

Local Anesthetics

The sensation of pain is carried to the central nervous system by unmyelinated C nerve fibers. Local anesthetics (LAs) act by blocking fast voltage-gated sodium channels in the cell membrane of the nerve, thereby inhibiting downstream propagation of an action potential and the transmission of painful stimuli.¹ The chemical structure of LAs is fundamental to their mechanism of action and metabolism. Local anesthetics contain a lipophilic aromatic group, an intermediate chain, and a hydrophilic amine group. Broadly, agents are classified as amides or esters depending on the chemical group attached to the intermediate chain.² Amides (eg, lidocaine, bupivacaine, articaine, mepivacaine, prilocaine, levobupivacaine) are metabolized by the hepatic system; esters (eg, procaine, proparacaine, benzocaine, chlorprocaine, tetracaine, cocaine) are metabolized by plasma cholinesterase, which produces para-aminobenzoic acid, a potentially dangerous metabolite that has been implicated in allergic reactions.³

Lidocaine is the most prevalent LA used in dermatology practices. Importantly, lidocaine is a class IB antiarrhythmic agent used in cardiology to treat ventricular arrhythmias.⁴ As an anesthetic, a maximum dose of 4.5 mg/kg can be administered, increasing to 7.0 mg/kg when mixed with epinephrine; with higher doses, there is a risk for central nervous system and cardiovascular toxicity.⁵ Initial symptoms of lidocaine toxicity include dizziness, tinnitus, circumoral paresthesia, blurred vision, and a metallic taste in the mouth.⁶ Systemic absorption of topical anesthetics is heightened across mucosal membranes, and care should be taken when applying over large surface areas.

Allergic reactions to LAs may be local or less frequently systemic. It is important to note that LAs tend to show cross-reactivity within their class rather than across different classes.⁷ Reactions can be classified as type I or type IV. Type I (IgE-mediated) reactions evolve in minutes to hours, affecting the skin and possibly leading to respiratory and circulatory collapse. Delayed reactions to LAs have increased in recent years, with type IV contact allergy most frequently found in connection with benzocaine and lidocaine.⁸

Topical Anesthesia

Topical anesthetics are effective and easy to use and are particularly valuable in patients with needle phobia. In certain cases, these medications may be applied by the patient prior to arrival, thereby reducing visit time. Topical agents act on nerve fibers running through the dermis; therefore, efficacy is dependent on successful penetration through the stratum corneum and viable epidermis. To enhance absorption, agents may be applied under an occlusive dressing.

Topical anesthetics are most commonly used for injectable fillers, ablative and nonablative laser resurfacing, laser hair removal, and tattoo removal. The eutectic mixture of 2.5% lidocaine and 2.5% prilocaine as well as topical 4% or 5% lidocaine are the most commonly used US Food and Drug Administration–approved products for topical anesthesia. In addition, several compounded pharmacy products are available.

After 60 minutes of application of the eutectic mixture of 2.5% lidocaine and 2.5% prilocaine, a 3-mm depth of analgesia is reached, and after 120 minutes, a 4.5-mm depth is reached.⁹ It elicits a biphasic vascular response of vasoconstriction and blanching followed by vasodilation and erythema.¹⁰ Most adverse events are mild and transient, but allergic contact dermatitis and contact urticaria have been reported.^11-13 In older children and adults, the maximum application area is 200 cm², with a maximum dose of 20 g used for no longer than 4 hours.

The 4% or 5% lidocaine cream uses a liposomal delivery system, which is designed to improve cutaneous penetration and has been shown to provide longer durations of anesthesia than nonliposomal lidocaine preparations.¹⁴ Application should be performed 30 to 60 minutes prior to a procedure. In a study comparing the eutectic mixture of 2.5% lidocaine and 2.5% prilocaine versus lidocaine cream 5% for pain control during laser hair removal with a 1064-nm Nd:YAG laser, no significant differences were found.¹⁵ The maximum application area is 100 cm² in children weighing less than 20 kg. A study of healthy adults demonstrated safety with the use of 30 to 60 g of occluded liposomal lidocaine cream 4%.¹⁶

In addition to US Food and Drug Administration–approved products, several compounded pharmacy products are available for topical anesthesia. These formulations include benzocaine-lidocaine-tetracaine gel, tetracaine-adrenaline-cocaine solution, and lidocaine-epinephrine-tetracaine solution. A triple-anesthetic gel, benzocaine-lidocaine-tetracaine is widely used in cosmetic practice. The product has been shown to provide adequate anesthesia for laser resurfacing after 20 minutes without occlusion.¹⁷ Of note, compounded anesthetics lack standardization, and different pharmacies may follow their own individual protocols.

Regional Anesthesia

Regional nerve blockade is a useful option for more widespread or complex interventions. Using regional nerve blockade, effective analgesia can be delivered to a target area while avoiding the toxicity and pain associated with numerous anesthetic infiltrations. In addition, there is no distortion of the tissue architecture, allowing for improved visual evaluation during the procedure. Recently, hyaluronic acid fillers have been compounded with lidocaine as a means of reducing procedural pain.

Blocks for Dermal Fillers

Forehead
For dermal filler injections of the glabellar and frontalis lines, anesthesia of the forehead may be desired. The supraorbital and supratrochlear nerves supply this area. The supraorbital nerve can be injected at the supraorbital notch, which is measured roughly 2.7 cm from the glabella. The orbital rim should be palpated with the nondominant hand, and 1 to 2 mL of anesthetic should be injected just below the rim (Figure 1). The supratrochlear nerve is located roughly 1.7 cm from the midline and can be similarly injected under the orbital rim with 1 to 2 mL of anesthetic (Figure 1).

Lateral Temple Region
Anesthesia of the zygomaticotemporal nerve can be used to reduce pain from dermal filler injections of the lateral canthal and temporal areas. The nerve is identified by first palpating the zygomaticofrontal suture. A long needle is then inserted posteriorly, immediately behind the concave surface of the lateral orbital rim, and 1 to 2 mL of anesthetic is injected (Figure 1).

Malar Region
Blockade of the zygomaticofacial nerve is commonly performed in conjunction with the zygomaticotemporal nerve and provides anesthesia to the malar region for cheek augmentation procedures. To identify the target area, the junction of the lateral and inferior orbital rim should be palpated. With the needle placed just lateral to this point, 1 to 2 mL of anesthetic is injected (Figure 1).

Blocks for Perioral Fillers

Upper Lips/Nasolabial Folds
Bilateral blockade of the infraorbital nerves provides anesthesia to the upper lip and nasolabial folds prior to filler injections. The infraorbital nerve can be targeted via an intraoral route where it exits the maxilla at the infraorbital foramen. The nerve is anesthetized by palpating the infraorbital ridge and injecting 3 to 5 mL of anesthetic roughly 1 cm below this point on the vertical axis of the midpupillary line (Figure 1). The external nasal nerve, thought to be a branch of cranial nerve V, also may be targeted if there is inadequate anesthesia from the infraorbital block. This nerve is reached by injecting at the osseocartilaginous junction of the nasal bones (Figure 1).

Lower Lips
Blockade of the mental nerve provides anesthesia to the lower lips for augmentation procedures. The mental nerve can be targeted on each side at the mental foramen, which is located below the root of the lower second premolar. Aiming roughly 1 cm below the gumline, 3 to 5 mL of anesthetic is injected intraorally (Figure 1). A transcutaneous approach toward the same target also is possible, though this technique risks visible bruising. Alternatively, the upper or lower lips can be anesthetized using 4 to 5 submucosal injections at evenly spaced intervals between the canine teeth.¹⁸

Blocks for Palmoplantar Hyperhidrosis

The treatment of palmoplantar hyperhidrosis benefits from regional blocks. Botulinum toxin has been well established as an effective therapy for the condition.^19-21 Given the sensitivity of palmoplantar sites, it is valuable to achieve effective analgesia of the region prior to dermal injections of botulinum toxin.

Wrists
Sensory innervation of the palm is provided by the median, ulnar, and radial nerves (Figure 2A). At the wrist, the median nerve lies between the tendons of the flexor carpi radialis muscle and the palmaris longus muscle. To facilitate identification of the palmaris longus muscle, instruct the patient to oppose the thumb and little finger while flexing the wrist. The needle should be inserted between the 2 tendons, just proximal to the wrist creases (Figure 2B). Once the fascia is pierced, 3 to 5 mL of anesthetic is injected.

The ulnar nerve is anesthetized between the ulnar artery and the flexor carpi ulnaris muscle. The artery is identified by palpation, and special care should be taken to avoid intra-arterial injection. The needle is directed toward the radial styloid, and 3 to 5 mL of anesthetic is injected roughly 1 cm proximal to the wrist crease (Figure 2B).

Anesthesia of the radial nerve can be considered a field block given the numerous small branches that supply the hand. These branches are reached by injecting anesthetic roughly 2 to 3 cm proximal to the radial styloid with the needle aimed medially and extending the injection dorsally (Figure 2B). A total of 4 to 6 mL of anesthetic is used.

Ankles
An ankle block provides anesthesia to the dorsal and plantar surfaces of the foot.²² The region is supplied by the superficial peroneal nerve, deep peroneal nerve, sural nerve, saphenous nerve, and branches of the posterior tibial nerve (Figure 3A).

To anesthetize the deep peroneal nerve, the extensor hallucis longus tendon is first identified on the anterior surface of the ankle through dorsiflexion of the toes; the dorsalis pedis artery runs in close proximity. The injection should be placed lateral to the tendon and artery (Figure 3B). The needle should be inserted until bone is reached, withdrawn slightly, and then 3 to 5 mL of anesthetic should be injected. To block the saphenous nerve, the needle can then be directed superficially toward the medial malleolus, and 3 to 5 mL should be injected in a subcutaneous wheal (Figure 3C). To block the superficial peroneal nerve, the needle should then be directed toward the lateral malleolus, and 3 to 5 mL should be injected in a subcutaneous wheal (Figure 3C).

The posterior tibial nerve is located posterior to the medial malleolus. The dorsalis pedis artery can be palpated near this location. The needle should be inserted posterior to the artery, extending until bone is reached (Figure 3C). The needle is then withdrawn slightly, and 3 to 5 mL of anesthetic is injected. Finally, the sural nerve is anesthetized between the Achilles tendon and the lateral malleolus, using 5 mL of anesthetic to raise a subcutaneous wheal (Figure 3C).

Conclusion

Proper pain management is integral to ensuring a positive experience for cosmetic patients. Enhanced knowledge of local anesthetic techniques allows the clinician to provide for a variety of procedural indications and patient preferences. As anesthetic strategies are continually evolving, it is important for practitioners to remain informed of these developments.