Does Botulinum neurotoxin type A treatment for sialorrhea change oral health?

Botulinum neurotoxin type A (BNT-A) intrasalivary gland injections in patients with neurological disorders have been known to effectively treat hypersalivation. However, oral health can be compromised with increasing the dose. The aim of this study was to find out the therapeutic effect of low-dose, ultrasonography-controlled BNT-A injections into the bilateral parotid and submandibular glands on oral health in the treatment of sialorrhea. Twenty patients diagnosed with Parkinson's disease (PD), amyotrophic lateral sclerosis (ALS), and other neurological disorders, including stroke or birth trauma, received BNT-A injections with salivary tests before and 1 month after the injections. Drooling was evaluated using subjective scales and objective assessment of salivary flow rate and oral health (salivary composition and cariogenic bacterial counts). A significant decrease was found in salivary flow rate at 1- and 3-month follow-up in the BNT-A treated group. There was no significant change in salivary composition or cariogenic bacterial counts. BNT-A injections according to the current protocol can effectively manage sialorrhea while maintaining oral health. Oral health can be considered the mirror of general human health, as the cause of many diseases. Saliva plays a crucial role in protecting the oral cavity. The present study is of high clinical relevance because, although earlier research has proved the effect of Botulinum neurotoxin type A injections on reduction in saliva flow, data about the risks of the treatment method to the oral condition through affecting saliva composition has so far been missing.