Negative effects on oral motor function after submandibular and parotid botulinum neurotoxin A injections for drooling in children with developmental disabilities

Children with neurodevelopmental disabilities, such as cerebral palsy, often struggle with excessive drooling, which can seriously impact their daily lives. Botox injections into the salivary glands can help reduce drooling. Doctors can inject either the submandibular glands under the jaw (two-gland injections) or both the submandibular and parotid glands near the ears (four-gland injections). While effective, these injections may also have side effects on oral motor functions such as eating, drinking, and speaking. This study aimed to describe the side effects of four-gland Botox injections, and compare them to an earlier study that focused on the side effects of two-gland injections.

This study included 125 children with neurodevelopmental disabilities who received four-gland Botox injections after two-gland injections did not reduce drooling enough. About 4 out of 10 children (36%) had side effects, mainly involving problems with eating or swallowing saliva. Most of these side effects were mild and went away within 4 weeks.

The frequency, type, and duration of side effects were similar to what was seen with two-gland injections. In the four-gland group, more lifestyle adjustments, such as changes to eating habits, were needed. In contrast to the two-gland group, no severe side effects or long-lasting changes were reported.