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Late Effects





Chemotherapy and radiation therapy (RT) for childhood cancer can both lead to an increased risk of dental problems with abnormal tooth development and an increased risk of dental caries.

The risk is especially severe when:

  • RT is given at a young age (less than 5 years) to the mouth and/or salivary glands
    • Young children are especially vulnerable to growth problems after RT.
  • Azothioprine is given to patients who have had a BMT (bone marrow transplant)
  • Chemotherapy is given at age less than 5 years (affects dental development)
  • Chronic graft vs host disease after BMT


Tooth and enamel development problems:

Both chemotherapy and RT have an impact on dental development and enamel formation.  This can lead to an increased susceptibility to dental disease. 

There may be very abnormal tooth development in young children (with subsequent absence of teeth or roots) and abnormal enamel development.

Abnormal development of enamel:

  • Malformed enamel is rougher and promotes bacterial plaque accumulation.
  • Thinner enamel makes the tooth less resident to acid attack by plaque, leading to tooth decay1



The parotid glands are very sensitive to RT.

After treatment patients often experience a dry mouth due to lack of saliva (Xerostomia). 

This significantly increases the risk factor for dental disease. 

RT can cause a permanent reduction in saliva production and this results in more severe oral/dental problems than chemotherapy (chemotherapy effects on saliva production are typically more transient).



RT may also damage the temporo-mandibular joint (TMJ) leading to trismus (inability to opent the mouth wide).  This may make it difficult to clean the teeth and again increase the risk of dental caries.



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