Cephalometric Norms in an Iranian Kurdish Population According to the Steiner Analysis

Cephalometric analyses norms and orthodontic software have been mainly developed for Caucasians. Thus, they might not be true for other ethnical groups. This study sought to determine cephalometric norms of an Iranian Kurdish population according to Steiner analysis. In this cross-sectional study, 100 lateral cephalograms of adult orthodontic patients between 18 - 30 years including 40 males and 60 females with normal occlusion and symmetrical faces were evaluated. Lateral cephalograms were traced and analyzed based on Steiner’s cephalometric parameters. Data were analyzed using SPSS. Differences between Kurdish and Caucasian norms were analyzed using one-sample t-test. Independent t-test was used to compare males and females (P < 0.05). The SNA, SNB, ANB, SND (Sella-Nasion-D point), interincisal angle, GoGn-SN L1-NB (both angular and linear measurements), SL (distance from Sella point to L, which is the projection of the most-anterior point in the body of mandible or pogonion on SN and SE (distance from Sella point to E point, which is the intersection of a line drawn from the most distal limit of the posterior surface of condyle head and SN) values were significantly different between the Kurdish population and Caucasian norms (P < 0.05). No significant differences existed in Occl-SN (occlusal plane to SN) and U1-NA (both angular and linear measurements) between the Kurdish population and the Caucasians (P > 0.05). Kurdish males and females were significantly different in terms of SND, Occl-SN, GoGn-SN and U1-NA angles, U1-NA distance and SL and SE values (P < 0.05). No significant difference existed between Kurdish males and females in SNA, SNB, ANB, interincisal angle and L1-NB (P > 0.05). Cephalometric norms for Kurdish adults are different from those of Caucasians. The norms obtained in our study can be used for orthodontic treatments and orthognathic surgeries in Kurdish population.