20-MHz ultrasonographic measurement of skin and cartilage thickness in patients with normal and reconstructed external ears

Background: The surgical reconstruction of the external ear according to Weerda is a proven method to correct malformed or amputated auricles. Our goal was to test the usefulness of high-frequency ultrasound in measurement of layer-thickness of auricles. Method: Using a 20-MHz B-Mode ultrasonographic method (Dermascan C, adn-Medizintechnik, Hamm, Germany) we measured the thickness of skin and cartilage layers in patients with normal auricles (n=47) and reconstructed auricles (n=15) in vivo. Results: The average thickness of the cutis of normal auricles was 0.8 mm, the subcutis and the cartilage layer 0.6 mm thick on average. In reconstructed auricles, the thickness of the cutis averaged 1.0 mm, the subcutis 1.1 mm, and the cartilage layer (to the extent that it could be visualized) 3.0 mm. Discussion: The results demonstrate a good approximation of the thicknesses of the different layers (cutis and subcutaneous tissue) in reconstructed and natural external ears, but the cartilage of the reconstructed auricles is clearly thicker. Conclusions: The 20-MHz B-Mode ultrasound is suitable for examining the methods of plastic surgery in malformed auricles. Based on the demonstrated results, surgical modifications should be assessed in future.