Transverse (a) and sagittal section (b) of the distal root of a 1st and the mesial root of a 2nd molar of a right maxilla exhibiting minimal interdental bone imaged with Micro-XCT; the white dotted lines indicate the position of the other section, respectively; note: bone resorption (black arrows), root resorption (white arrows), blood vessels (white stars), and residual interdental bone (white triangle). (c) 3D images of alveolar bone of the buccal roots in (a); bone surface of the distal root-bone complex shows resorption tracks (left image); holes on bone surface of the mesial complex indicate entering of blood vessels (right image). De = dentin, RB = interradicular bone, SC = secondary cementum, RC = root canal, and En = enamel.
