Impact of CBCT on Orthodontic Pre-treatment Diagnosis and Treatment Planning

Objective: Cone-beam computed tomography (CBCT) is often used as a diagnostic and treatment-planning tool for orthodontics; however, little data supports its routine use.  The purpose of this study is to investigate the impact of CBCT as a diagnostic and treatment-planning aid in orthodontics.

Method: 23 practicing orthodontists in Southern California evaluated six patient cases representing a wide range of orthodontic problems (including crowding, severe skeletal asymmetry, TMD, impactions). After reviewing patient histories, study models, photos, and traditional radiographs, participants provided a hypothetical diagnosis (DX) and treatment plan (TP) and associated confidence (0-100%). The participants then evaluated CBCT scans for these patients and noted changes (CG), enhancements, or confirmations to the original DX and TP and a final confidence (0-100%).  The participant and patient characteristics associated with changes to the DX and TP or an increase in associated confidence were determined.

Result: For the 137 diagnoses, a CBCT was requested 58 times resulting in 22 DX changes and 23 TP changes.   Initial DX and TP confidence ranged from 1-100% (DX mean 85% median 90%, TP mean 83% median 90%), increasing after review of the CBCT to means of 93% and 92% respectively (p<0.5).  Two of 6 cases were associated with significantly (p<0.05) lower initial TP confidence (confidence by case 92, 88, 89, 71, 76, 85%), significantly (p<0.05) higher post-CBCT diagnosis confidence changes (change in percent by case 3.9, 5.2, 5.0, 14.3, 17.0, 4.3), and the greatest number of CBCTs requested (#CBCT ordered 1, 5, 6, 21, 18, 7).  Considering components of variance associated with change in confidence, variance among participants was significantly greater than among the cases (93% participants, 7% cases, p<0.5).

Conclusion: CBCT scans resulted in DX and TP changes and increased the diagnostic and treatment-planning confidence of orthodontists.  Specific patient cases were associated with increased requests for CBCT scans.