The causes that can trigger xerostomia include:
The elderly, those with neurodegenerative diseases, head and neck cancer patients, and those with autoimmune conditions such as Sjögren’s syndrome are disproportionately affected. Oropharyngeal dysphagia refers specifically to difficulty in initiating a swallow due to dysfunction at or above the upper esophageal sphincter, and represents a large proportion of dysphagia cases.
Chemotherapy and radiation therapy – head and neck cancer. Despite major improvements in radiation therapy for head and neck cancer (HNC), the most prevalent long-term complications are radiation-induced salivary gland hypofunction and xerostomia.
The major salivary glands (SGs) are highly radiosensitive; ionizing radiation leads to reduced saliva flow rate and changes in both the composition and function of saliva.Consequently, patients may suffer from dental decay, oral infections, difficulties with speaking, chewing, and swallowing, sleep disturbance, worsened nutritional state, and impaired quality of life (QoL).
The pathophysiology behind radiation injury of SGs is multifactorial and includes an acute and late response that may continue for years, characterized by chronic inflammation, acinar, local progenitor and stem cell loss and the development of fibrosis and im- paired environment for surviving acinar cells.