**1. Mechanism of action**

It inhibits the release of acetylcholine (ACh) from nerve endings via cleavage of SNARE protein complex responsible for ACh release. Thus it affects the presynaptic nerve endings at the neuromuscular junction (NMJ) causing muscle paralysis (main site of action) [1], and the cholinergic postganglionic autonomic nerve fibers innervating the eccrine, salivary and tear exocrine glands (neurosecretory junction) [2, 4]. This inhibition is reversible within variable periods of time via the regeneration of synaptic junctions [1, 4].

Indications:

Despite being widely used for multiple indications, botulinum toxin's FDA approved indications are limited **Table 1**.

The indications of BTXN in the face is summarized in **Table 2**.


#### **Table 1.**

*FDA approved indications of botulinum toxin.*


**33**

1

2

**Table 2.**

**2. Storage and reconstitution**

*Botulinum toxin neuromuscular indications in the face.*

*required in men in all regions of the face [5].*

The various BTXN products are supplied as lyophilized powder containing vials

**Muscles written in bold** *are the injected muscles. Facial musculature varies between males and females, with increased strength and bulk in men. Thus, higher doses and increased number of injection points are generally* 

*Brow position is lowered with age "brow ptosis". Glabellar complex injection (20–40 U) lead to immediate lateral eyebrow elevation, followed by an entire brow lift that peaked 12 weeks post treatment. This effect is due to the toxin diffusion into the lower medial frontalis muscle fibers with subsequent increased tone in the upper and lateral frontalis fibers. Forehead lines is recommended to be done simultaneously with brow lift to maintain a neutral* 

*Exposure of* ≥*2 mm of the gingiva on smiling [8]. Done for younger patients with strong lip elevator complex [6].* <sup>3</sup> *Youthful face is a heart shape with fullness in the upper part and tapering toward the mandible [1]. It is essential to exclude parotid gland hypertrophy either primary or secondary to pathology as Sjögren syndrome or bulimia nervosa or parotid gland mass using clinical assessment and CT imaging, or volume loss related masseteric prominence [3, 15].*

except for rimabotulinumtoxin which is supplied in a liquid form [1].

*Botulinum Toxin for the Face*

Mentalis overactivity

Masseter overactivity (square jaw) / bruxism

Facial asymmetry Caused by Bell's

Acne and Sebum production

Gustatory sweating (Frey syndrome)

*position for the eye brow [6].*

palsy

*DOI: http://dx.doi.org/10.5772/intechopen.94495*

**muscles**

**Unites and Technique**

**Mentalis muscle** Intramuscular, 1–4 injection points 3–5 U/ point.

**Masseter muscle** Intramuscular, 1–6 injection points/ side, 5–15 U/injection.

the posterolateral corner [6, 8, 9].

Platysmal bands **Platysma** Only for patients with obvious platysmal bands, and good

fat [6].

30 U/ session [3, 6].

point equidistantly in the folds.

using the total dose of 10–40 units [10, 11].

production 2 U/injection site [12].

published reports on the results [13]

Intracutaneous injections of 4 U /cm2

Excess sebum production: Few reports of BTXN use as intradermal (1 cm apart forehead and check) or intramuscular injection (five fixed points in the forehead) in the forehead for management of excess sebum

Acne: one clinical trial has been registered using 1.5–3 U/ active lesions. The trial has been terminated with no

[14]

superiorly and 2 inferior and laterally.

Average of 3 points are injected at the center of the masseter square at least 1.5 cm from the mandibular border [7], one

Caucasians tends to need lower doses than Asians with longer periods of effect. The injection is to be directed at

cervical skin elasticity with no or minimal submental

Intramuscular or deep intracutaneous, typically 2 bands are injected at a time with 3 points of injection in each band, 1–1.5 cm apart, 1–5 U/ injection point, total 15 U/ band and

For horizontal neck folds: Superficial intradermal, 1–2 U/

The contralateral active side is injected using small doses (1–2 U) of Ona BTXN into muscles of the normally functioning side (the zygomaticus, risorius and orbicularis oris muscles) and 5–10 U into the masseter muscle [6, 10]. For post Bell's palsy synkinesis the paralyzed side is injected either as four periocular injections or into the affected muscles as orbicularis oculi, orbicularis oris and frontalis

**Indications Responsible** 

*Cosmetic Surgery*

Rimabotulinumtoxin

*FDA approved indications of botulinum toxin.*

**Indications Responsible** 

**muscles**

**Procerus Corrugator** supercilii Depressor supercilii Orbicularis oculi

**Nasalis (upper fibers)**

**superioris alaeque** 

**nasi**
