Image distortion and spatial resolution of a commercially available cone-beam computed tomography machine.

Introduction: Our objective was to evaluate images produced by a commercially available cone-beam computed tomography (CBCT) machine (i-CAT model 9140-0035-000C, Imaging Sciences International, Hatfield, Pa) for measurement and spatial resolution (ie, the ability to separate 2 objects in close proximity in the image) for all settings and in all dimensions.

Methods: A custom phantom containing 0.3 mm diameter chromium metal markers approximately 5 mm apart in 3 planes of space was developed for analyzing distortion and measurement accuracy.

Nonsurgical treatment of a patient with a Class III malocclusion.

A patient with a bilateral Class III molar relationship came to the Department of Orthodontics clinic at Case Western Reserve University. Our first choice for treatment was a combination of orthodontic therapy and orthognathic surgery. The patient, however, opted for a nonsurgical approach that took 34 months and involved the extraction of 4 first premolars and a remaining deciduous tooth, and Class III vertical elastics.

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.