Abstract :
[en] This experimental clinical study aimed to assess the potential benefits of cone beam computed tomography (CBCT) in dental aligner digital treatment planning. Ten patients (2 males/8 females, aged 28.9 ± 4.7 years) underwent complete orthodontic examination including intra-oral scanning, CBCT at reduced dose (0.3mm voxel, 16x10cm), a lateral cephalometric radiograph, six intra-oral and three extra-oral photographs. Three experienced orthodontists realized each patient’s treatment planning without CBCT and, one month later, with the CBCT information, allowing planning adjustments if necessary. A dental comparative analysis was made in terms of number and severity of bone dehiscences, number of aligners, number of root collisions, amount of stripping, dental egression/ingression, relative extrusion/intrusion, vestibulo-lingual translation, mesio-distal translation, rotation, tip and torque movements, arch widths between canines, premolars and first molars. It was hypothesized that three-dimensional (3D) visualization of the roots and alveolar bone influences overall orthodontic treatment planning.
Results showed that the mean number of virtual bone dehiscences per patient decreased significantly from 16.3 ± 2.8 to 14.7 ± 3.3 when using CBCT information (mean drop 1.6 ± 0.8, P<0.001) when using CBCT information. The percentages of teeth (n=834) scoring A (no dehiscence) increased from 41.4% to 47.1%; for B1 (more than 75% in the bone) from 43.5% to 48.3%; for B2 (between 75% and 50% in the bone), the percentage decreased from 7.4% to 3.2%; for B3 (between 50% and 25% in the bone), from 3.4% to 0.6%, and for B4 (less than 25% in the bone), from 4.3% to 0.7%. Significant positive correlations were found between the change in severity of dehiscences with dental egression/ingression movements (r=0.41), relative extrusion/intrusion (r=0.49), vestibulo-lingual translation (r=0.25), and torque movements (r=0.70). The gingival phenotype did not seem to influence bone dehiscences numbers or severity.
This experimental clinical study demonstrated that using CBCT information reduces virtually all types of dental bone dehiscences, in number and severity. This may potentially decrease the occurrence of periodontal recessions during orthodontic treatment and may avoid root collisions.
