Cephalometric measurements and facial deformities in subjects with β-thalassaemia major

Abstract

This study was performed to identify cephalometric and facial features of patients with β-thalassaemia major. A total of 54 thalassaemic subjects were examined for craniofacial deformities, including 37 patients (24 males and 13 females, aged 5-16 years) who had lateral cephalometric radiographs. The thalassaemic groups were compared with a normal control group matched for sex and dental age, using a t-test. All thalassaemic patients had a Class Il skeletal base relationship. The average ANB angle was significantly larger than the controls in dental stages 2 and 3 (P < 0.05). Mandibular base length (Ar-Gn) was significantly less in thalassaemic patients than in controls, with the greatest differences (P < 0.001) found in the younger age group. The maxilla was of normal length (PNS-ANS, Ptm′-ANS′) and appeared prominent (3.3 mm in males and 5.1 mm in females) due to a reduced cranial base length (Ar'-S') and a short mandible (Ar′-P′). Vertically, thalassaemic patients showed a significantly increased maxillary/mandibular planes angle in all groups, with differences ranging between 6.19 and 12.55 degrees (P < 0.001). Thalassaemic patients also showed a reduced posterior facial height (S-Go, Ar-Go) and increased anterior facial proportions. Of the 54 thalassaemic patients examined, 17 per cent had severe facial disfigurements (grade 3).