Date of Award

5-2006

Document Type

Thesis

Degree Name

Master of Dental Science (MDS)

Program

Orthodontics

Research Advisor

Edward F. Harris, Ph.D.

Committee

Sue C. Kaste Christopher Rowland William G. Parris

Abstract

Acute lymphocytic leukemia (ALL) is a life-threatening disease primarily affecting children. Treatment currently consists of chemotherapy sometimes in combination with head irradiation. The literature documents the damage of treatment to the teeth (e.g., congenital absence, microdontia, abnormal crown- root ratios). The present study assessed the effects of treatment for ALL on the tempos of dental maturation (i.e., dental age) in a mixed longitudinal sample of 72 children treated for ALL at St Jude's Children's' Research Hospital, Memphis, Tennessee. Panoramic radiographs had been taken as indicated to assess and maintain dental health in this retrospective study. Dental age was quantified both on a tooth-specific basis and averaged across all scorable teeth using published standards for American whites. The tempo of toothformation was gauged as dental age (DA) minus chronological age (CA). Children were developmentally normal (DA=CA) at the onset of ALL, and there was no sex difference in response to treatment. No statistically significant developmental delay was found during the first two years from the onset of treatment, perhaps because tooth mineralization progresses slowly enough that effects were obscured. From two years onward, DA was significantly depressed. The effect of chemotherapy alone only had a slight negative effect on DA. The addition of irradiation to chemotherapy had a significant additive effect on DA, as well as increasing the incidence of developmental variants such as stunted roots (i.e., roots with apical closure prior to achieving normal length). Importantly, there was no evidence of a compensatory increase in the tempo of growth following treatment. The chemotherapeutic treatment for ALL is a serious stressor to the body's tempo of growth, and the addition of irradiation therapy significantly adds to the negative effect on the tempo of dental maturation. Significant developmental delay was not seen until two years after the start of treatment, either because the dentition is buffered from the stresses of treatment or because the morphological changes are slow to occur. The end result of treatment for ALL is delayed tooth maturation in addition to the previously documented risks of developmental dental anomalies.

DOI

10.21007/etd.cghs.2006.0346

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