Evaluation Cephalometric Norms in Iranian Adult Live in Ahvaz Using Mcnamara Analysis

Today diagnosis and treatment planning in patients for orthodontic or surgical treatment must be consistent on the same ethnic cephalometric norms. This study aimed to determine the cephalometric norms of the Iranian sample living in Ahvaz by McNamara's analysis and to verify the existence of gender dimorphism and compare it with the standard norms and similar studies.

Cephalograms of 79 patients (39 males, 40 female in19-29 years old) were selected from the Orthodontic department of Ahvaz Dental School archive during 2018-2019. The subjects had a Class 1 molar relationship with a balanced profile, no history of orthodontic or surgical treatment or trauma, and no congenital anomalies. According to the McNamara analysis 8 linear and 4 angular measurements were traced manually and analyzed statistically by Shapiro-Wilk, independent t-test, and Mann-Whitney tests with a meaningful level of p value < 0.05.

According to our findings significant differences were in the effective length of the maxilla and mandible, Maxillo-mandibular differences, Distance point A and pogonion from N perpendicular line, 1.3 lower face height (p value < 0.05) but in the upper and lower incisor position and facial axis and mandibular plane angle were not (p value > 0.05).

Iranian sample had more retruded Mid-face, mandible, and chin and shorter lower face height (p value < 0.05). But incisor positions, mandibular plane angle, and facial axis were in the line of McNamara norms. Despite the differences between Iranian adults and Caucasian norms, in surgical and orthodontic treatment plane McNamara's analysis was applicable for Iranians.