Xerostomia Causes: Radiotherapy | Chemotherapy | Surgery | Traumatic Injuries
Some good books on coping with Radiotherapy and Chemotherapy
Causes of Xerostomia - Radiotherapy: Ionizing radiation can cause various degrees of alterations to the salivary glands, damage occurs with the destruction of acinar cells with subsequent atrophy and fibrosis of the glands. The degree of salivary gland alteration is related to the dose-volume factor, patient's age, and the time of exposure to radiation. Though radiotherapy improves the quality of life of cancer patients, but the average salivary flow decreases with increased radiotherapy management. The glands sensitive to radiation are parotid glands, the submandibular glands, the sublingual glands, and minor salivary glands. Also it is interesting to note that serous acinar cells appear to be more sensitive to radiation than mucous cells. The patient's initial clinical response post radiation reflects increased salivary gland problems associated with dry mouth and pain. Post radiotherapy patients have a tendency of decreased salivary flow continued for a few months after radiotherapy due to progressive degeneration of tissue and the maximum recovery of this may occur from six to twelve months post radiotherapy treatment. The changes reported in patients post radiotherapy are changes in salivary composition, slight decrease of pH capacity, and an increase in the concentration of magnesium, calcium, protein, and sodium chloride.
Causes of Xerostomia - Chemotherapy: Chemotherapy also causes changes in salivation with the total saliva having changes in its composition or being slightly decreased. However, alterations caused by chemotherapy are usually transient and less severe than those caused by radiotherapy, but if both these treatments are combined together on a cancer patient, the effects are much more pronounced than when performed separately. Most chemotherapeutic drugs mainly affect both healthy and cancerous mucosal cells inducing little resistance to trauma with increased risk of producing spontaneous ulcers, mucositis (generalized inflammation of mucosal tissues), infections, bleeding gums, tongue, and lips in addition to increased pain which makes it difficult for a cancer patient to drink and eat properly.
Causes of Xerostomia - Surgery and Traumatic Injuries:
The level of trauma caused from accidents involving the face and neck area and salivary glands as well as surgery to remove tumors can cause loss of innervation, parenchymal damage, and damage to the excretory ducts of the salivary glands compromising their blood supply. Patients with broken excretory ducts of salivary glands undergo surgical replacement of the salivary excretory duct to preserve its specific function. Besides surgery and traumatic injuries to salivary glands, there are other factors that influence the amount of salivary flow in an individual such degree of hydration of the individual, age, emotional status, the biological rhythm, and masticatory function.