Table 6.

Table of side effects

Study	Facial asymmetry/disappearance time		Other side effects
	BT-A	Placebo
	N	N	N
Wu et al. [27]	5 patients/ in 7 weeks	0	Transient oedema in the area of injection was observed in 3 patients (2 in the BT-A group and 1 patient from the placebo group), facial oedema developed in 2 days and disappeared within 7 days.
Shehata et al. [28]	4 patients/-	0	Haematoma BT-A 1 and placebo 2
			Itching BT-A 1 and placebo 1
			Pain BT-A and placebo 1
Zúñiga et al. [29]	2 patients/-	0	Haematoma at the site of administration (2 patients in BT-A group).
Zhang et al. [30]	3 patients/ in 6 weeks	0	Transient oedema in the injection was observed in 2 patients (both from BT-A 25 U group) and disappeared within 5 days.

N = number; U = units per ml of solution; BT-A = botulinum toxin type A; TN = trigeminal neuralgia.