Measuring the dimensions of bone defect based on the sagittal view of the CBCT data.A: Cementoenamel junction (CEJ) at the labial side, B: Alveolar crest at the labial side, C: Coronal border of a fenestration, D: Apical border of a fenestration, DC: Distance between A and B measured by the CBCT method (mm), FC: Distance between C and D measured by the CBCT method (mm)