Lip dimensions of an adult Nigerian population with normal occlusion.

INTRODUCTION The soft tissue paradigm is placing greater emphasis on the importance of the soft tissue profile to orthodontic treatment planning. The purpose of this study was to determine the lip dimensions of a Nigerian adult population; compare the male and female values and to compare the values obtained for Nigerians with those reported for other population. METHODOLOGY Lateral cephalometric radiographs of 100 students (44 males and 56 females) of the College of Medicine, University of Lagos, aged 18 to 25 years were taken. Selected subjects were of Nigerian ancestry with normal occlusion and a harmonious facial appearance. The radiographs were manually traced and the upper and lower lip length and thickness of each subject was measured. Statistical analysis was carried out using SPSS, while the male and female values were compared using student's t-tests. RESULTS Mean values for the lip dimensions were computed for the entire sample. Marked sexual dimorphism was observed with the males having thicker and longer upper and lower lips than the females. The Nigerian sample also had a longer upper lip and a thicker and shorter lower lip than that reported for Caucasians. However, both population had a similar upper lip thickness. CONCLUSION Cephalometric norms were developed for the lip dimensions of a Nigerian population. Marked sexual dimorphism was observed in the Nigerian population studied with the males having longer and thicker lips than the females. The lip dimensions of the Nigerian population studied differed from that reported for Caucasians and other racial groups.