Cephalometric norms for 6-17 year-old Iranians with normal occlusion and well-balanced faces

BACKGROUND: Caucasian norms are still used in the orthodontic treatment of Iranian patients, despite the different ethnic backgrounds of Iranians. The aims of this study were to evaluate the cephalometric features of an Iranian population and to establish cephalometric norms for Iranian living in the central region of Iran (Isfahan). MATERIALS AND METHODS: A total of 238 lateral cephalometric radiographs and dental casts of Iranians (142 females and 96 males; aged 6-17 years) with acceptable profiles and Class I dental relationships were analyzed in five age groups. The mean value, standard deviation and range of 20 angular and linear variables were calculated. The resulting norms for Iranian were compared with Caucasian norms and results of other studies on Iranian population using t-test. Male and female groups were also compared using the independent t-test (P < 0.05). RESULTS: Iranians tend to have an increased angle of convexity and IMPA (incisor to mandibular plane angle) and bimaxillary protrusion as compared with norms of Down's analysis. Anterior lower face height and anterior face height were greater than Burrstone's sample measurement. Sella-Nasion (S-N) length was greater than Rakosi's norm. Iranians tend to have an increased ANB (A point-Nasion-B point) angle as compared with Steiner's norms. Males tend to have greater cranial dimensions than females as indicated by the statistically significant increase in anterior face height and S-N length (P < 0.05). CONCLUSION: Iranians have distinct cephalometric features, which should be used as a reference in treating Iranian orthodontic patients.