No abstract

Cephalometric norms have been established for the McNamara analysis for different age, racial and ethnic groups. To establish McNamara cephalometric norms for a sample of Black South African adults and to compare with Caucasian norms. Thirty lateral cephalograms of a sample of eligible untreated Black adult subjects was retrieved from archives in the Department of Orthodontics at the Medunsa Oral Health Centre. They were traced and digitized using Dolphin Imaging® computer software. The McNamara analysis was performed. The one sample t-test was performed to compare study values with McNamara norms. The two sample t-tests were used to determine statistical differences between the data for genders. The mean age of the study subjects was 24 years (SD=3.9). Two-thirds of the linear measurements were significantly higher than the McNamara norms. The angular measurements of female subjects were significantly higher than McNamara's reference values. As regards gender differences, almost two-thirds of male linear measurements were higher than females, and the differences were statistically significant in half of the measurements. In contrast, though all higher, female angular measurements showed no statistically significant differences. Gender and racial differences exist in cephalometric norms measured using the McNamara analysis. Radiographic cephalometry is a vital tool for clinical and research orthodontics. 1 Since its introduction by Broadbent 2 in 1931, numerous cephalometric analyses have been described over the years. These analyses are frequently used by orthodontists and maxillofacial surgeons for diagnosis, treatment planning, growth analysis and evaluation of treatment results. 3