Clinical application of 3D imaging for assessment of treatment outcomes

Abstract

This paper outlines the clinical application of CBCT for assessment of treatment outcomes, and discusses current work to superimpose digital dental models and 3D photographs. Superimposition of CBCTs on stable structures of reference now allow assessment of 3D dental, skeletal and soft tissue changes for both growing and non-growing patients. Additionally, we describe clinical findings from CBCT superimpositions in assessment of surgery and skeletal anchorage treatment.

Figures

Figure 1

Construction of 3D models from Cone-beam CT (CBCT) scans taken before and after Class III malocclusion orthopedic treatment with miniplates. . A, B and C, Pre-treatment models. A, Hard tissue. B, Soft tissue. C, Visualization of surface models with semi-transparency of soft tissues. (Color version of figure is available online.)

Figure 2

A- Anatomic structures used to register 3D models of non-growing subjects in which we use the whole surface of the cranial base for registration of before and after treatment images. B- Anatomic structures used to register 3D models of growing subjects in which we use the anterior surface of the cranial base for registration of before and after treatment images For growth assessment we have registered using the anterior cranial fossa surfaces, that have growth completed in early chidlhood, in such a way that the superimpositions describe growth relative to the individual cranial base. C- Fully automated calculation of rotational and translational parameters between the images. (Color version of figure is available online.)

Figure 3

Visualization of treatment changes with overlay of registered 3D surface models. A, B and C show different ways of visualization. A, Pre-treatment model (white) and post-treatment (semi-transparent red). B- Pre-treatment (red in the online version) and post-treatment (triangular mesh). The cranial base was cropped to show details of maxillo-mandibular changes. C, Soft tissue changes, pre-treatment (orange in the online version) and post-treatment (semi-transparent gray). (Color version of figure is available online.)

Figure 4

Quantification of changes. A- Pre-treatment (white) and post-treatment 3D models (surface distance changes color map). Anterior displacement/remodeling is shown in red and posterior displacement/remodeling in blue. B- Color maps of hard and soft tissue regional changes. C- Isoline contours adjusted to quantify changes in the upper lip region. D- Isoline contours adjusted to quantify changes in the upper lip region. (Color version of figure is available online.)

Figure 5

Soft tissue changes 1 year surgery. A, B and C, Mandibular advancement .D, E and F, Mandibular setback. A, Transparency overlays of superimposed pre-surgery (white) and 1 year post-surgery (red in the online version). B and C, Surface distance color maps of soft tissue changes in the chin area. D, Transparency overlays of superimposed pre-surgery (red in the online version) and 1 year post-surgery (red in the online version). E and F, Surface distance color maps of soft tissue changes in the chin area. (Color version of figure is available online.)

Figure 6

Tooth movement changes. Registration of pre and post-treatment digital models using the palatal rugae. (Color version of figure is available online.)

Figure 7

Registration of patient 3D photograph to two CBCTs taken at the same day. A, First CBCT acquisition registered to 3D photograph. B, Second CBCT acquisition taken the same day. Both manual and soft tissue based registration were used to register the photograph and the CBCT surface model (3DMDVultus Software version 1.1, 3DMD Atlanta), the contours of the CBCT lower lip, chin and neck do not match the contours of the 3D photograph. (Color version of figure is available online.)