Association of Abo Blood Groups and Rh Factor with Sagittal and Vertical Skeletal Malocclusion- An Observational Study

Abstract

Introduction: Various studies have proved the association between several disease including dental crowding, malocclusion and craniofacial deformities with blood group. Certain skeletal problems in sagittal plane are heritable and the skeletal muscle volume and strength, a heritable trait varies with different facial patterns. Aim: To evaluate the association between ABO blood groups and Rhesus (Rh) factor with skeletal malocclusions in sagittal and vertical plane. Materials and Methods: An observational study was conducted with a sample of 240 participants who reported to Department of Orthodontics in SRM Dental College and Hospital, Chennai, Tamil Nadu, India seeking orthodontic treatment over a period of two years from September 2018 to December 2020. Participants were assessed for skeletal malocclusion in sagittal and vertical plane and for their ABO and Rh blood grouping. Chi-square test was used for determining the association between sagittal and vertical skeletal malocclusion with ABO and Rh blood grouping. The association of the gender and the malocclusion was determined as a secondary outcome of the study. Results: A total of 240 participants (mean age: 19.81±5.95 years; 95 males and 145 females) were observed and data was analysed. A significant association was found between Rh positive blood group and skeletal class II malocclusion with high angle (p-value 0.025). Skeletal class I malocclusion with high angle was found to be associated significantly with O+ group (p-value <0.001). The female gender was found to be associated significantly with sagittal skeletal class II malocclusion with high angle (p-value 0.049). Conclusion: There is an association between the ABO blood groups and skeletal sagittal malocclusion and vertical skeletal pattern. Skeletal class II malocclusion with high angle pattern was associated significantly with Rh+ blood group and class I skeletal malocclusion with high angle pattern was significantly associated with O+ blood group.

Keywords

• heritability of malocclusion
• rhesus factor
• sagittal skeletal malocclusion
• vertical skeletal pattern