Computed tomography-generated templates: a new approach to frontal sinus osteoplastic flap surgery.

BACKGROUND

The aim of this study was to present a new technique for frontal sinus template creation used in osteoplastic flap surgery, obviating the need for the traditional 6-ft Caldwell radiograph.

METHODS

Seventeen human cadaver skulls were studied prospectively. Using digital addition algorithms of sequential coronal computed tomography (CT) images of the frontal sinus to create a composite image, an image is printed to 1 cm = 1 cm scale. A frontal sinus template was created using this processed image and compared with a control 6-ft Caldwell radiograph.

RESULTS

The mean variance between corresponding vertical points on the templates was 0.71 mm (95% confidence interval, 0.56-0.87 mm). The mean variance between horizontal points was 1.11 mm (95% confidence interval, 0.97-1.28 mm). The mean difference in width was 2.46 mm. The plain film templates were always wider than the CT-generated templates.

CONCLUSION

The CT-generated frontal sinus templates are virtually identical to the Caldwell radiograph-derived templates. They may obviate the need for additional imaging and minimize the potential errors commonly associated with 6-ft Caldwell templates.