Inclusion Criteria:  CBCT scans for male and female Egyptians between the ages of 20 and 60 years. CBCT scans with the required complement of teeth.  Exclusion Criteria:  CBCT scans that lack a proof of age or date of birth. CBCT scans with the required teeth showing pathological processes in the apical bone. CBCT scans with overlying teeth. CBCT scans in which the required teeth were filled, prosthetically restored or carious.