Title: Ethnic Differences in the Prevalence of Short Root Anomaly
Brenna Christensen (Presenter)
University of Alabama at Birmingham School of Dentistry
Craig Rousso, University of Alabama at Birmingham School of Dentistry
Chee Paul Lin, University of Alabama at Birmingham School of Dentistry
Mary MacDougall, University of Alabama at Birmingham
Ejvis Lamani, University of Alabama at Birmingham School of Dentistry
Objectives: Short Root Anomaly (SRA) is a poorly understood developmental disorder presenting with short roots with rounded apexes and reduced crown to root ratios. SRA can significantly compromise the patient’s dental treatment and may increase the risk of root resorption during orthodontic treatment. The prevalence of SRA is reported to range from 2.4-10%; however it has not been evaluated in various ethnic groups. Objective: To measure root/crown (R/C) ratios of fully developed permanent teeth using panoramic radiographs and determine the prevalence of SRA and its relationship to gender and ethnicity.
Methods: A total of 353 patient radiographs (114 Caucasians, 114 African Americans and 126 Hispanics; 48% males and 52% females) were analyzed. Root lengths and crown heights were measured using a modified Lind’s method. SRA was diagnosed as having R/C ratios less than 65% of mean values for maxillary central incisors. Chi-square statistics were used to evaluate the effects of gender, ethnicity and their interaction on R/C ratios.
Results: The overall SRA prevalence was 5.67%. Although no gender differences in the SRA prevalence were identified, we found that ethnic differences were statistically significant (p=0.003681). SRA distribution varied from 1.75% in African Americans to 3.54% in Caucasians and 11.11% in Hispanics. SRA individuals had a mean R/C ratio of 1.11 for the maxillary central incisors a 37% reduction from the average population value of 1.77.
Conclusions: Our data establishes for the first time the prevalence of SRA in African Americans and supports Hispanics having the highest rate of any ethnic group reported to date. Therefore, carefully diagnosing this developmental condition, especially in the Hispanic orthodontic patients, is important to better understand the patient’s risk of developing root resorption.