Applied Physiology of the Parotid Gland

The major function of salivary glands is the production of saliva, which performs many functions including lubrication of the food bolus, maintaining the oral cavity pH within 6 to 7, maintaining teeth integrity, fighting bacteria, aiding taste and digestion, and providing a continuous lavaging biofilm for the oral cavity. Saliva is actively produced in high volumes relative to the mass of the salivary glands and is almost completely controlled extrinsically by both parasympathetic and sympathetic divisions of the autonomic nervous system. Some researchers used bilateral tympanic neurectomy for patients with ptyalism (drooling) with good initial results. Others advocated bilateral parotid duct rerouting ± bilateral submandibular gland excision for long-term treatment of drooling. Intra-glandular Botulinum toxin may also have good results for patients with hyper-sialorrhea. Most resting salivary gland flow arises from the submandibular glands and surgery should focus on this gland to control uncontrolled sialorrhea.