Human mandibular densitometric values in Nigeria's major ethnic groups.

BACKGROUND: Published data on baseline densitometric values of human mandible in the Nigerian population is lacking. We hypothesized that bone density may vary among and within each ethnic group across Nigeria. The aim of this study was to determine the normative densitometric values of human mandible among three major ethnic groups in Nigeria. METHODS: Digital Orthopantomographs (OPGs) of eligible participants were uploaded to the freely available ImageJ software to determine the bone densities at anterior mandible, mandibular body and mandibular angle. Statistical analysis was done using SPSS version 22.0. The level of significance was set at p < 0.05. RESULTS: The mean mandibular BMD for adult Nigerians were 127.81 ± 26.02, 94.15 ± 23.62 and 119.29 ± 20.89 grayscale values for anterior mandible, mandibular body and mandibular angle respectively. Participants aged 18-20 years had the highest mean BMD at the anterior mandible (138.68 ± 16.8 grayscale value), while the lowest mean was seen in the 31-35 years age group (121.56 ± 22.77 grayscale value). There were significant differences in BMD across ethnic groups at all studied mandibular sites. Anterior mandible showing the largest difference (p < 0.001), followed by body (p = 0.010) and angle (p = 0.033). Anterior mandible mean BMD differed significantly between Yoruba and Igbo ethnic groups. CONCLUSION: We found site-specific BMD variations across different mandibular regions and Nigerian ethnic groups.