Date of Award

5-2005

Document Type

Thesis

Degree Name

Master of Dental Science (MDS)

Program

Orthodontics

Research Advisor

Edward Harris, Ph.D.

Committee

Gregory Hutchins, D.D.S., M.S. Quinton Robinson, D.D.S., M.S.

Abstract

Sickle cell disease (SCD) is a genetic disorder affecting over 100,000 African Americans. While once lethal, medical treatment now allows those with SCD to lead comparatively normal lives, and these children are more frequently seeking orthodontic treatment. We report here on a cephalometric study of a contemporary cohort of 62 children with SCD (27 SC and 35 SS genotypes). This was a cross-sectional study of children from the MidSouth between 3 and 16 years of age, and results were co mpared to standards in Richardson’s Atlas of growth of American Black children in Nashville, TN. Raw values were converted to age- and sex-specific standard deviations and were tested with analysis of variance. Six conclusions were drawn : (1) Craniofacial dimensions are reduced, subjects’ faces are small at all ages, probably as a result of chronic hypoxia due to hemolytic anemia. (2) There was no discernible difference in severity between SC and SS genotypes. (3) In contrast, females regardless of genotype typically were more severely affected than males. (4) Children became progressively more affected with age. Adolescents were disproportionately affected compared to children (larger SDs), so the lin ear and angular deviations were greater in the young adult dentitions when most subjects seek orthodontic treatment. (6) SCD causes the face to become hyperdivergent. We do not know the process, but the planes of the face—palatal plane, o cclusal plane, mandibular plane (including Y-axis, gonial angle, and FMA)—progressively steepen with age, especially in adolescence. This combination of small linear dimensions and progressive hyperdivergence creates several dental compensation s. And, importantly, they create special challenges for the orthodontist. Understanding the altered craniofacial growth in sickle cell disease will aid health care providers in the treatment of these children.

DOI

10.21007/etd.cghs.2005.0022