Cephalometric norms of Nigerian children

Introduction: The purpose of this study was to develop cephalometric standards for Nigerian children. Methods: The average values of 7 dentoskeletal angles were determined from standardized lateral head radiographs of 100 schoolchildren (aged 11 to 13 years; mean, 12.6 years) in Enugu, a city in southeastern Nigeria. The children, born to Nigerian parents of Igbo ancestry (Igbo is 1 of the 3 major ethnic groups in Nigeria), were selected on the basis of a well-balanced face and acceptable profile, Class I occlusion with normal overjet and overbite, minor or no crowding or spacing, and no history of orthodontic treatment. Results: There were no statistically significant differences in cephalometric measurements between boys and girls; thus, the data were combined for analysis. The mean values and standard deviations obtained for the measured variables were: SNA, 85.5° (± 4.3°); SNB, 81.2° (± 4.0°); ANB, 4.3° (± 2.5°); UI-FP, 122.8° (± 7.5°); Ll-MP, 98.8° (± 5.8°); Ul-LI, 109.1° (± 8.0°); and FMA, 26.1° (± 5.0°). Conclusions: Compared with the norms for other ethnic groups, Igbo children have a prognathic relationship of the maxilla and the mandible to the anterior cranial base with a tendency toward a protrusive skeletal pattern. The children also exhibited prominent bimaxillary proclination with procumbent and protrusive maxillary and mandibular incisors and a steep Frankfort-mandibular plane angle. The findings emphasize the need for group-specific norms for orthodontic diagnosis and treatment planning, and provide cephalometric standards for Igbo children.