RESUMEN
Thalassemia is a group of inherited diseases with a defect in the synthesis of hemoglobin. Severe thalassemic subjects suffer from craniofacial deformities and malocclusion due to bone marrow hyperplasia compensating for ineffective erythropoiesis. Blood transfusions are used to maintain life and reduce complications. The transfusions may have benefits in reducing craniofacial and dentition abnormalities. However, appropriate therapy is still controversial. This study evaluated the effect of different transfusion regimens on craniofacial appearance and dentition. Ninety-two severe thalassemic patients, aged 6 -13 years, were divided into 3 groups according to the frequency of transfusion: 1) high transfusion: more than 12 times/year. 2) low transfusion: 6-12 times/year. 3) occasional transfusion: less than 5 times/year. The appearance and dentition were evaluated and compared among groups. Most subjects in the high transfusion group had a normal appearance and a class I molar and incisor relationship with normal overjet and overbite. More than half of subjects in the low and occasional groups showed craniofacial abnormalities and malocclusion, particular in the occasional group. Frequency of transfusion has an effect on craniofacial appearance and dental occlusion; only high frequent transfusions were effective in preventing craniofacial and dental defects.