Localization of Salivary Glands for Botulinum Toxin Treatment: Ultrasound Versus Landmark Guidance

BACKGROUND: Sialorrhea is a troublesome symptom in a variety of neurological diseases. Recently, local injection of botulinum toxin into the salivary glands was approved for treatment of sialorrhea, and injection guidance by anatomical landmarks was suggested. OBJECTIVE: To compare the accuracy of ultrasound versus previously proposed anatomical landmarks for localizing the salivary glands. METHODS: In a cross‐sectional study in 21 adults, landmark positions (LM) of the parotid gland (PG) and the submandibular gland (SG) were identified following published recommendations. The ultrasound position (US) was defined as the position representing the maximum gland thickness. The distance between positions, gland thickness, and optimal injection depth were recorded by US. RESULTS: Gland thickness differed significantly between LM and US positions (PG, 4 vs. 17.8 mm; P