In vitro analysis of the accuracy of subtraction radiography and computed tomography scanning for determination of bone graft volume.
OBJECTIVE
This study evaluated the accuracy of digital subtraction radiography (DSR) and three-dimensional computed tomography (3D CT) for determination of bone graft volume in the maxillofacial region.


METHODS
Standardized bone defects were made on the top of the alveolar ridge in 10 dry pig mandibles. To resemble the clinical situation, a bone block was harvested from the symphyseal region of the mandible and fixed in the defect. True bone graft volume was determined by the water displacement technique (VOL I) and correlated to direct measurements by calipers (VOL II). The mean gray value of the bone graft as imaged by DSR was correlated to the directly measured thickness. Furthermore, VOL I was correlated to the 3D CT of the bone graft (VOL III) and to the 3D CT with the bone graft fixed in the defect (VOL IV).


RESULTS
There was a strong correlation between VOL I and VOL II (r = .95), whereas there was a poorer correlation between mean gray level in DSR and measured bone thickness (r = .63). A strong correlation was also registered between VOL I and VOL III (r = .97) and VOL I and VOL IV (r = .97).
Jensen
J
J
Department of Oral and Maxillofacial Surgery, Aarhus University and Aarhus University Hospital, Denmark.
Kragskov
J
J
Wenzel
A
A
Sindet-Pedersen
S
S
D016301:Alveolar Bone Loss / Q000000981:diagnostic imaging* / Q000209:etiology; D000540:Alveolar Ridge Augmentation / Q000009:adverse effects / Q000379:methods* / Q000592:standards; D000818:Animals; D015519:Bone Density; D016025:Bone Transplantation; D015203:Reproducibility of Results; D013382:Subtraction Technique; D013552:Swine; D014057:Tomography, X-Ray Computed