Botulinum toxin therapy: a tempting tool in the management of salivary secretory disorders

The aim of the study was to investigate the feasibility and effectiveness of botulinum toxin therapy in salivary secretory disorders.

We treated 24 patients with botulinum neurotoxin type A for drooling, salivary fistulas, sialoceles, recurrent parotitis, and Frey's syndrome; each parotid gland and submandibular gland received 25 to 60 and 10 to 40 mouse units, respectively, per session. All the patients other than those with Frey's syndrome underwent, for diagnostic purpose, color Doppler ultrasonography (Hitachi H 21; frequency, 7.5 MHz, Scanner, Kashiwa, Japan), and Minor's test was carried out for gustatory sweating; pretreatment magnetic resonance sialography (Philips Gyroscan Intera, Eindhoven, The Netherlands) and sialoendoscopy were also performed in selected cases. The follow-up included clinical and ultrasonographic examinations and Minor's test.

A clinical improvement was observed in all patients: complete clinical recovery in 12, subtotal in 6, and partial in 6. A self-assessment test suggested the cessation of sweating by the 10th day in most patients with Frey's syndrome. Botulinum toxin lost its effectiveness approximately after 4 months, requiring further administrations especially for drooling. No major side effects were observed with the exception of transitory paresis of the lower branch of the facial nerve in a patient with concomitant autonomic diabetic neuropathy.

Our findings suggest that botulinum toxin therapy is valid for the nonsurgical management of patients with salivary secretory disorders; the use of color Doppler ultrasonographic monitoring warrants the safety of the procedure.