Establishment of reference mandibular plane for anterior alveolar morphology evaluation using cone beam computed tomography

To propose a method of establishing the reference mandibular plane （MP）, which could be reestab- lished according to the coordinates of the reference points, and then facilitate the assessment of anterior alveolar morphology using cone beam computed tomography （CBCT）, sixty patients with bimaxillary protrusion were randomly selected and CBCT scans were taken. The CBCT scans were transferred to Materialism＇s interactive medical image control system 10.01 （MIMICS 10.01）, and three dimensional models of the entire jaws were constructed. Refer- ence points determining the reference MP were po- sitioned in the coronal, axial, sagittal windows, and the points were exactly located by recording their coordinates in the interfaces of software. The ref- erence MP provided high intra-observer reliability（Pearson＇s r 0.992 to 0.999）, and inter-observer reli- ability （intra-class correlation coefficients （ICCs） 0.996 to 0.999）.