The influence of slice orientation in 3D CBCT images on measurements of anatomical structures

Abstract

Longitudinal anatomical structures can be studied through slicing perpendicularly to their general orientation. The digital nature of 3D cone beam computed tomography (CBCT) images creates a need to define the general orientation of such structures. The aim is to investigate the influence of slice orientation on the measurements of thickness and overall width of a mandible. Most often the mandibular structure is explored by browsing through coronal views. A more sophisticated approach consists of the study of slices perpendicular to the general shape of the mandible obtained through tracing the mandibular arch in an occlusal view. Slicing perpendicularly to the mandibular canal containing the inferior alveolar nerve (IAN) is presented as a third slicing strategy. The latter mimics the slicing approach used in classical anatomic studies of the mandible. When comparing all three strategies, significant differences in measurements of the buccal, lingual and inferior thickness of the walls can be detected. In 69% of cases, the difference in overall width at the level of the IAN exceeds one mm between measurements on a slice constructed perpendiculary to the IAN and a coronal slice. © Springer International Publishing Switzerland 2014.