Comparing orthodontic treatment outcome between orthodontists and general dentists with the ABO index

This study used the American Board of Orthodontics (ABO) Objective Grading System (ABO index) (ABOI) to compare treatment outcome between patients treated by orthodontic specialists (OS) and patients treated by general dentists (GP). The sample (n = 196) consisted of 126 dental casts of patients treated by OS and 70 treated by GPs. All casts were collected in 1997 and 1998 from 10th grade students attending high schools in Cuyahoga County, Ohio, and were scored by 1 operator (Y.A.) calibrated in the use of the ABOI. The mean ABOI score for the OS group was 26.0 +/- 11.4 compared with 29.6 +/- 12.8 for the GP group. This difference was significant at the P < or = .05 level. Of the 7 components used in the ABOI, alignment of teeth was found to be the most significant between groups (OS mean = 5.39 +/- 4.37 versus GP mean = 7.8 +/- 5.21, P < or = .0007). In this sample, a significantly lower ABOI score was found for patients treated by OS compared with patients treated by GP.