A new predictive modality of cranial bone thickness

The objective of this study was to evaluate A-mode ultrasound in the assess ment of cranial bone thickness utilizing an in vivo animal model. A prospec tive study was performed that identified four standardized calvarial points in 10 Landrace porcine skulls. The individual points were scanned with an A-mode ultrasonic transducer to obtain bone thickness measurements. The sam e points were measured subsequently using digital calipers for objective co mparison. The accuracy of each of the measurement modalities was evaluated for inter- and intrarater reliability. The association between ultrasonic a nd caliper measurements was evaluated using Student's t-test, Pearson's cor relation coefficient, and linear regression models to assess the effect of confounding variables. The mean difference between the ultrasonic and the c aliper values was 0.31 +/- 0.22 mm (standard deviation). The statistical an alyses employed strongly supported the predictive value of ultrasound as a function of the true calvarial thickness (p < 0.05, r > 0.88, R-2 = 0.89). The results suggest that ultrasound is an accurate reflection of cranial bo ne thickness in an in vivo animal skull model. The development of a portabl e, noninvasive ultrasonic device can have substantial clinical implications for craniomaxillofacial surgery.