Association of ABO Blood Groups with Malocclusion in Population of Jaipur, India: A Prospective Study

Background: One of the most important human genetic characteristics is the relationship between the ABO blood group system and diseases and deformities. Aim: The aim was to fi nd out the relationship between blood groups and malocclusion by comparing blood groups of each individual with one’s malocclusion. Materials and Methods: A total of 300 subjects (age range 15-28 years) were recruited in the study for whom complete information about their malocclusion and blood group type was recorded as per the ABO system. The subjects were equally divided into two groups: Half of the subjects in malocclusion and the remaining half in normal occlusion group who served as control. In normal occlusion group, only those subjects were included, which on clinical evaluation, showed, bilateral Angles Class I molar relationship with acceptable overjet and overbite and well-aligned arches or minimal crowding while the individuals with malocclusion were classifi ed into three groups according to Angles classifi cation. Results: Statistical analysis with Chi-square test showed that association of blood groups with malocclusion is statistically highly signifi cant (P < 0.001) indicating the prevalence of malocclusions is highest in blood group B, followed by A, O and AB with the least prevalence (B > A > O > AB). Blood groups B and A had the increased incidence of association with malocclusion while blood groups O and AB had decreased incidence of association with malocclusion. Conclusions: The evaluation of the relationship between blood and malocclusions revealed that blood groups have an association with malocclusions with prevalence of malocclusions being highest in blood group B, followed by A, O and AB in Jaipur population.