Injecting botulinum toxin

Dr Apratim Goel (MD, DNB) and Dr Zeba Chhapra (DDVL) elaborate on the aesthetic indications of botulinum toxin with respect to the differences in different genders – men, women and transgender. 

B otulinum toxin, produced from clostridium bacteria acts by blocking the presynaptic release of acetylcholine to the muscles, thereby causing temporary paralysis of the muscle. It is used for a variety of medical and aesthetic treatments from chronic migraines, overactive bladder, cervical dystonia, blepharospasm, hyperhidrosis, and facial wrinkles. This article focuses on the aesthetic indications of botulinum toxin such as facial lines and wrinkles, brow lift, face contouring, and reducing neck lines with respect to the differences in different genders. This article will help understand the techniques, outcomes, complications, and satisfaction among different genders. Botulinum toxin is one of the commonly performed non-invasive procedures for both men and women. It is important to understand the subtle differences to give a satisfactory aesthetic outcome.

Men are becoming increasingly aware of their cosmetic appearances and needs. Dermatologists and aesthetic practitioners need to understand the needs of men just as much as we do for women. However, the reason why men seek botulinum treatment are completely different from women and hence a deep understanding of the male anatomy as well as aesthetic preferences should be kept in mind. Women on the other hand, have specific needs when it comes to toxin injections. Apart from reducing the lines and wrinkles, they also need a subtle yet natural looking brow lift, a slimmer face, and softness in the platysma bands on the neck. Also, since a female face ages differently, the dosage as well as areas of botulinum injections vary significantly.

Transgenders are increasingly becoming a huge part of our aesthetic practice and it is equally important to understand their physiology and psychological needs, especially considering the need for change to either feminisation or masculation of their features.

The three main factors that should be considered while treating with botulinum toxin are: Anatomical differences, dosage, and aesthetic preference.

Anatomical Differences

Men have a greater muscle mass as compared to women. Studies have shown a significantly higher skeletal muscle in men as compared to women. This could be the result of hypertrophic effect of testosterone on muscles as well as genetic increased muscle mass.

Dr Apratim Goel

Dr Goel is the CEO /Medical Director of Cutis Skin Solution. With 20 years of experience, her specialisation includes Dermatology with special interest in lasers, threads, Medispa and injectables. She also conducts training courses for doctors.

Brow shape: Evaluating faces of models, actors, and faces in paintings have proven to show that women look great with a high eyebrows and men look better with a horizontal brow. Aesthetic physicians and makeup artists know that the male brow is lower than the female brow and not arched. Arching the brow of a male patient can result in feminine looking feature, which is important to do when required for a transgender individual.

Glabella: Standard dosing on glabella complex for women range between 12 to 24 units of toxin. Men, on the other hand, will be untreated if given the same dosage. Considering the hypertrophy of muscle in men, an average of 20 to 50 units of toxin may be required for the glabellar complex. Transgender individuals looking for feminisation of features need similar to higher than the dosage given to men. The technique of injection remains the same, but the dosing needs to be carefully decided based on each muscle size.

Another point to consider while treating the glabellar complex is to know that most men may have a broader corrugator supercilii muscle with its distal fibres inserting far laterally. When injecting the corrugator supercillii, notice the distal end of the muscle fibres, and make sure to inject into the lateral fibres in men. Failure to inject the toxin into the far lateral fibres will enable the patient to contract the muscle laterally and not medially giving an unnatural appearance.

 Injecting botulinum toxin to the corrugator muscles causes a medial brow lift. Injecting into the lateral fibres of the corrugator muscle also diffuses into the lower fibres of the frontalis muscle, which can cause the brow to look flat, which is suitable for men. Women on the other hand, need the brow lift and hence the lateral fibres have to be injected in lower doses, and carefully, so as to not diffuse the toxin into the frontalis muscle.

If the lateral fibres of the corrugator is under injected in men, over time, the frontalis will be able to lift the lateral part of corrugator giving a high arched appearance in men, which is not desirable.

The approach to treating patients with botulinum toxin is to call the patient back after two weeks of injection to see if more dosage is required. Sometimes, in men, an additional, 10 to 20 units of toxin is needed for a complete result. Showing the pre post pictures two weeks after the treatment guarantees the satisfaction of the patient. Crow’s feet: Following the wrinkles around the eyes, along the orbicularis, is usually the right injection point for all genders. Males however can have wrinkles going more laterally and additional injection points may be needed laterally. Care should be taken to not inject too low on the crow’s feet as this might weaken the zygomaticus muscle and affect the smile.

Inject less units on the highest point of crow’s feet at the tail of eyebrow for men as it causes a lift in the brow giving a high arched appearance.

In women, the average units for crow’s feet is usually between 9 to 12. In men, this can vary from 10 to 15 units. In transgenders, looking for feminisation, this could be 12 to 18 units.

The frontalis

When treating the wrinkles on forehead caused by the frontalis muscle, it is important to evaluate the muscle in animation and check whether the frontalis is a single wide sheet of muscle or divided into two muscle bellies. Men most often have a single wide sheet of frontalis where the midline fibres overlap considerably. Many young men are also seen to have forehead lines due to being expressive and causes more hypertrophy of the muscle. Some men can have wrinkles that extend in the superior portion of frontalis, near the hair line or slightly higher where the hairline originates. Leaving this portion untreated can lead to satisfactory results and unnatural appearance.

Mid and Lower Face Differences

Men usually do not require botulinum toxin in the lower face as women. Some areas where botulinum toxin gives a nice aesthetic outcome are the nasalis, the DAO, and the mentalis. The hypertrophic mentalis gives the appearance of a pebbly chin. Injecting toxin relaxes the chin and gives an excellent outcome for both men and women.

Many women prefer av shaped or oval shaped face and masseter hypertrophy is an issue easily treated with botulinum toxin, depending on the hypertrophy and muscle size dosage, which is usually between 15 to 30 units.

Men on the other hand prefer a broad jawline and want to keep the masseter muscle as is to achieve the broad lower face look. Masseter muscle is injected in men having medical condition like bruxism or pain in the TMJ. Most often, fillers are used to achieve the strong wide jawline in men.

Transgender individuals – looking for feminisation of features – require a higher dosage of toxin to reduce the bulky hypertrophic master muscle. On an average, 40 to 80 units may be required.

When injecting, the masseter muscle care should be taken to not inject too high or too medially as it can lead to an asymmetric smile that can be traumatic for the patient till the toxin wears off. It is better to draw the line that is normally from the tragus to the corner of the mouth, 1 cm lower, to skip the risorius intersection with the masseter muscle.

It should be noted that the mid-face and lower-face require multiple treatment modalities such as fillers or energy-based devices along with botulinum toxin to achieve the desired satisfactory outcome.

In conclusion

It is important for aesthetic physicians to assess and customise the treatment for the patient’s face. Do not ignore that men have larger muscles. Administer the dosage based on the anatomical understanding of the muscles, rather than company guided dosing.

Give attention to male and transgender cosmetic patients. This will not only improve the outcome of the treatment but attract all genders towards botulinum toxin treatment. The dermatology community needs to expand our understanding of the underlying biology of different genders. Especially when injecting botulinum toxin, gender counts!

Dr Zeba Chhapra

Dr Chhapra practices at Cutis Skin Solution in Mumbai. She is a dermatologist with five years of experience and has special interest in lasers, threads and injectables.