The aim of this study was to investigate possible associations between sickle cell anemia (SCA) and the severity of dental malocclusion (MO). This was a retrospective cohort study of 93 individuals with SCA (G1) and 186 individuals without the disease (G2). SCA patients were randomly selected by a simple draw from patients treated in the Centro de Hematologia e Hemoterapia do Maranhão (HEMOMAR) in northeastern Brazil. Patients aged between 16 and 60 were included after being tested for the hemoglobin S gene. G2 consisted of individuals living in the same residence as the patients. The Dental Aesthetic Index (DAI), as well as some morphological deviations not included in DAI, were used for the orthodontic evaluation of MO. Poisson regression with robust variance adjustment was employed to estimate relative risk (RR). In the multivariate analysis, SCA was associated with moderate (RR = 1.36) and very severe MO (RR = 8.0). SCA is correlated with anterior tooth loss (RR = 1.94), anterior spacing (RR = 1.66), overjet (RR = 1.87), anterior crossbite (RR = 1.94), and open bite (RR = 1.94). Thus, SCA is a risk factor for moderate and very severe MO.

This study aims to critically review the literature in respect to craniofacial bone abnormalities and malocclusion in sickle cell anemia individuals. The Bireme and Pubmed electronic databases were searched using the following keywords: malocclusion, maxillofacial abnormalities, and Angle Class I, Class II and lass III malocclusions combined with sickle cell anemia. The search was limited to publications in English, Spanish or Portuguese with review articles and clinical cases being excluded from this study. Ten scientific publications were identified, of which three were not included as they were review articles. There was a consistent observation of orthodontic and orthopedic variations associated with sickle cell anemia, especially maxillary protrusions. However, convenience sampling, sometimes without any control group, and the lack of estimates of association and hypotheses testing undermined the possibility of causal inferences. It was concluded that despite the high frequency of craniofacial bone abnormalities and malocclusion among patients with sickle cell anemia, there is insufficient scientific proof that this disease causes malocclusion