Dentists often encounter cancer patients, who are to undergo radiotherapy or have received it in the recent past. Besides cancer therapy, these patients need dental treatment for different ailments. Therefore, it becomes paramount important for a dentist to know the effects of large doses of ionizing radiation on oral mucosa.
In this section, we shall talk about the effects of radiation on oral tissues.
Radiation Effects on Teeth
Excessive radiation does not have direct effect on adult teeth,
In the long term, fibrotrophy of pulp tissues occurs in the pulp chamber.
In developing teeth, teeth buds are destroyed, if radiation is done before calcification.
During the period of teeth calcification, radiation causes hypoplasia, hyper calcification, arrested development, arrested root formation or even absent roots.
Radiation carries is a form of acute caries that occurs following changes in the salivary glands. It is caused by decreased flow, decreased pH, decreased buffering capacity, and increased viscosity of the saliva.
Radiation Effects on Oral Mucosa
The oral mucosa starts showing signs of mucositis two weeks after the radiotherapy. The lesion gets covered by a white or yellow pseudomembrane. Usually it gets infected with candida later on.
The healing of oral mucosa takes place within three months after radiotherapy. In the long term, progressive atrophy of mucosa occurs. Patients start showing signs of mucosal atrophy in the form of abnormal sensation or burning sensation to hot spicy foods, or to even air in the advanced stage of mucosal atrophy.
Radiation Effects on Taste Buds
Taste buds are also affected by radiotherapy. The patients usually complain of loss of or decreased taste sensation, termed as ageusia or hypogeusia respectively, three weeks after radiotherapy. The ability of the patients to taste falls 1000 to 10,000 times below normal level and is regained within two months to four months.
Radiation Effects on Bone
Radiation damages the fine vasculature of bone by endarteritis and obliteration of vasculature. Normal bone marrow is replaced by fatty or fibrous marrows. After radiotherapy, the endosteum does not show any osteoblastic or osteoclastic activity and bone becomes prone to infection, even from minor trauma and subsequent osteoradionecrosis.
Now you know the effects of excessive ionizing radiation on oral tissues. For more details, you can consult the reference book.
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Ref: White & Pharoah Oral Radiology Principles and Interpretations 5th Ed.