Craniofacial characteristics of B-Thalassemia Major patients – literature review

Background: Beta Thalassaemia (BT) is an inherited hematologic disorder, characterized by reduced beta-globin chains. Growth of the marrow cavities in BT causes skeletal deformities such as thinning of the cortical plates. Widening of the diploic spaces in the skull radiographically appears as trabecules arranged vertically in a typical “hair-on-end” form. Objectives: Present a comprehensive critical review of available literature concerning unique craniofacial manifestation patterns in BT affected patients. Methods: A PubMed search was conducted from 1966 to 2011. Inclusive criteria were clinical studies, case reports and reviews on craniofacial characteristics in BT. Excel worksheets were designed to list the articles meeting the inclusive criteria. Results: Seven comparative studies and case reports of Malaysian, Iranian, Jordanian Turkish, Mediterranean, Greek, Italian and Saudi-Arabian populations with a 5-43 year age range were included, totaling 134 patients, 78 male and 56 female. Convex profile and lip prominence were described in some of the cases. Most of the cases exhibited skeletal class II relations of mandibular origin due to a smaller and retrusive mandible. However, maxillary contribution to this A-P discrepancy is debated. A vertical jaw growth pattern, increased mandibular plane angle and smaller posterior facial height were found with possible explanations proposed. While mandibular proclination was seen in the patients, their maxillary incisor position was found to be normal or even retroclined, expressing a dento-alveolar compensation mechanism with almost no marked overjet expressed. In vertical dimension, overeruption of upper and lower incisors was described in some cases. Conclusion: The facial appearance of BT patients is unique and accompanied by specific craniofacial, jaw and dental characteristics which pose a challenge for orthodontists who strive to provide the best proper management.