Cancer Health Center

Altered dental growth and development is a frequent complication in long-term cancer survivors who received high-dose chemotherapy and/or head/neck radiation for childhood malignancies.[1,2,3,4,5,6,7,8] Radiation doses as low as 4 Gy have been shown to cause localized dental defects in humans.[9,10]

Developmental disturbances in children treated before age 12 years generally affect size, shape, and eruption of teeth as well as craniofacial development:

• Abnormal tooth formation manifests as decreased crown size, shortened and conical shaped roots, and microdontia; on occasion, complete agenesis may occur.
• Eruption of teeth can be delayed, including increased frequency of impacted maxillary canines.
• Shortened root length is associated with diminished alveolar processes, leading to decreased occlusal vertical dimension.
• Conditioning-induced injury to maxillary and mandibular growth centers can compromise full maturation of the craniofacial complex.

Because the changes tend to be symmetric, the effect is not always clinically evident. Cephalometric analysis is typically necessary to delineate the scope of the condition.

The extent and location of dental and craniofacial anomalies largely depend on the age at which cancer therapy was initiated and the cancer regimen used. Children younger than 5 or 6 years at the time of treatment (particularly those who undergo treatment that involves concomitant chemotherapy and head and neck radiation) appear to have a higher incidence of dental and craniofacial anomalies than do older patients or those who undergo only chemotherapy.[11,12]

The role and timing of orthodontic treatment for patients who have transplant-related malocclusions or other alterations of dental growth and development are not fully established. The number of successfully managed orthodontic interventions appears to be increasing; however, specific guidelines for management, including optimal force and pace with which teeth should be moved, remains undefined. The influence of growth hormone relative to improved development of maxillary and mandibular structures is yet to be comprehensively studied. Such studies may well influence recommendations for orthodontic treatment. (Refer to the PDQ summary on Late Effects of Treatment for Childhood Cancer for further information.)

Management of oral complications in pediatric patients is additionally challenging because of the relatively limited research base directed to oral toxicities. New, comprehensive research studies are thus needed.

References:

1. Cohen A, Rovelli R, Zecca S, et al.: Endocrine late effects in children who underwent bone marrow transplantation: review. Bone Marrow Transplant 21 (Suppl 2): S64-7, 1998.
2. Dahllöf G, Barr M, Bolme P, et al.: Disturbances in dental development after total body irradiation in bone marrow transplant recipients. Oral Surg Oral Med Oral Pathol 65 (1): 41-4, 1988.
3. Dahllöf G: Craniofacial growth in children treated for malignant diseases. Acta Odontol Scand 56 (6): 378-82, 1998.
4. Dahllöf G, Forsberg CM, Ringdén O, et al.: Facial growth and morphology in long-term survivors after bone marrow transplantation. Eur J Orthod 11 (4): 332-40, 1989.
5. Uderzo C, Fraschini D, Balduzzi A, et al.: Long-term effects of bone marrow transplantation on dental status in children with leukaemia. Bone Marrow Transplant 20 (10): 865-9, 1997.
6. Lucas VS, Roberts GJ, Beighton D: Oral health of children undergoing allogeneic bone marrow transplantation. Bone Marrow Transplant 22 (8): 801-8, 1998.
7. Dahllöf G, Heimdahl A, Bolme P, et al.: Oral condition in children treated with bone marrow transplantation. Bone Marrow Transplant 3 (1): 43-51, 1988.
8. Rosenberg SW, Kolodney H, Wong GY, et al.: Altered dental root development in long-term survivors of pediatric acute lymphoblastic leukemia. A review of 17 cases. Cancer 59 (9): 1640-8, 1987.
9. Fromm M, Littman P, Raney RB, et al.: Late effects after treatment of twenty children with soft tissue sarcomas of the head and neck. Experience at a single institution with a review of the literature. Cancer 57 (10): 2070-6, 1986.
10. Goho C: Chemoradiation therapy: effect on dental development. Pediatr Dent 15 (1): 6-12, 1993 Jan-Feb.
11. Näsman M, Forsberg CM, Dahllöf G: Long-term dental development in children after treatment for malignant disease. Eur J Orthod 19 (2): 151-9, 1997.
12. Hölttä P, Hovi L, Saarinen-Pihkala UM, et al.: Disturbed root development of permanent teeth after pediatric stem cell transplantation. Dental root development after SCT. Cancer 103 (7): 1484-93, 2005.