Assessment of the nasolabial angle in young Brazilian black subjects with normal occlusion

Black individuals present craniofacial characteristics which differ from those of other races, especially the white race, whose cephalometric analyses are usually considered as the standard in routine orthodontic diagnosis and treatment planning. Further studies are therefore needed to enable more accurate and specific diagnoses for this ethnic group. The present study was conducted in order to assess average values for the nasolabial angle in young Brazilian black individuals with normal occlusion, and to assess the occurence of sexual dimorphism. Thirty-six lateral skull, extraoral radiographs from Brazilian black individuals were selected from the archives of the Scientific Recordings Department, Orthodontics Graduate Program, School of Dentistry of Piracicaba, State University of Campinas (UNICAMP). The patients' ages varied from 10 to 14 years, they presented normal occlusion upon clinical examination, and had not been submitted to orthodontic treatment. The cephalometric landmarks from which the nasolabial angle was obtained and measured were traced by a single researcher. Statistical analysis and evaluation of the results led to the conclusion that the nasolabial angle of young Brazilian black individuals is sharper, i.e., the soft tissue profile is more protruded. The average value for the whole sample was 88.14 degrees +/- 12.52 degrees. The nasolabial angle was statistically smaller among females (p < 0.05), demonstrating the occurrence of sexual dimorphism.