Cortical Bone Thickness Variation at Potential Implant Sites in the Mandibular Posterior Region Among Nigerian Adults: A CBCT Study

Implant-based rehabilitation of the posterior mandible requires accurate pre-surgical knowledge of bone density and cortical thickness to ensure primary implant stability and osseointegration success. Significant variation in mandibular bone morphometry across populations has been documented globally, but CBCT-based assessment data for the Nigerian adult population are lacking. This cross-sectional analytical study measures buccal, lingual, and crestal cortical bone thickness at potential implant sites in the posterior mandible (premolar and molar regions) of 180 adult patients whose CBCT scans were available at the radiology archives of Lagos University Teaching Hospital and Aminu Kano Teaching Hospital, representing the South West and North West geopolitical zones respectively. Measurements were obtained at standardized anatomical reference points by a calibrated examiner. Association with age, sex, body mass index (BMI), and edentulous duration was assessed. Results reveal significant variation in cortical bone thickness between premolar and molar sites, with the premolar region demonstrating consistently greater buccal cortical thickness. Male patients showed greater mean cortical bone thickness at all sites. Patients with edentulous duration exceeding three years demonstrated significantly reduced crestal cortical bone thickness. BMI was not significantly associated with bone dimensions in this sample. The study provides foundational population-specific CBCT normative data for Nigerian dental implant planning and underscores the need for pre-implant CBCT assessment in all posterior mandibular implant cases. Keywords: cortical bone thickness, CBCT, dental implants, mandibular posterior region, Nigeria.