1Institute of Dentistry, Queen Mary University of London, 2Child Dental Health, Obafemi Awolowo University, 3Child Dental Health, Lagos University Teaching Hospital, 4Orthodontics, Khartoum Centre for Research and Medical Training
Thursday 11:45-12:00, Broadway III/IV
Little information on the timing of human permanent tooth formation in Africa is documented. The aim of this study was to compare mean age entering permanent mandibular tooth formation stages in four African and two British groups. Archived dental radiographs of 3548 female and 3085 male dental patients, aged 2-25 years of age were collected in Lagos, Nigeria, Khartoum, Sudan, Johannesburg and Pretoria, South Africa and London, UK. The formation stage of mandibular left teeth was assessed. Two key stages were analysed for these preliminary results: root one half (R1/2 when crown height=root length) and apex complete (Ac). Mean age entering these tooth stages was calculated using logistic regression with country and sex as explanatory factors and London Whites as the reference. Country of origin significantly affected mean age for all comparisons (P<0.01). Similarities in mean age were noted in the western and northern Sudanese groups as well as the White and Bangladeshi British groups. Mean age for many tooth stage comparisons were later in the two Sudanese groups compared to other groups. Few young individuals from Nigeria and South Africa were available and early forming teeth could not be compared, however, both stages of third molars were significantly earlier in Nigerian and South Africans than other groups. These results suggest a complex pattern of permanent tooth formation within Africa.