A cephalometric assessment of the nasolabial angle of an adult Nigerian population

Objective: One of the most important components of orthodontic diagnosis and treatment planning is an evaluation of the patient's soft tissue profile. An assessment of the nasolabial angle is a vital component of this evaluation. The purpose of this study was to establish norms for the nasolabial angle of an adult Nigerian population; compare the male and female values and to compare the values obtained for Nigerians with those reported for other populations. Method: Lateral cephalometric radiographs of one hundred students (44 males and 56 females) of the College of Medicine, University of Lagos, aged 18-25years were taken. Selected subjects were of Nigerian ancestry with normal occlusion. The radiographs were manual ly t raced and the nasolabial angle of each subject measured. Result: A mean value of 84.35° +13.71° was computed for the entire sample. No statistically significant difference was observed between the male and female values (p>0.05), although 0 0 the males recorded a lower nasolabial angle (83.70 ) than the females (85.28 ).The nasolabial angle recorded in this study was similar to that reported for South African blacks, but much lower than that reported for Caucasian populations. Conclusion: The mean nasolabial angle of 84.35 + 13.71 was observed in the Nigerian population studied. Sexual differences were not observed; however, the values observed in this study differ from that reported for Caucasians and other racial groups. Key words: Cephalometrics, nasolabial angle, Nigerian population