High-resolution ultrasound imaging for jawbone surface

Although medical specialties have recognized the importance of using ultrasonic imaging, dentistry is only beginning to discover its benefit. This has particularly been important in the field of periodontics, which studies infections in the gum and bone tissues that surround the teeth. This study investigates the feasibility of using a custom-designed high-frequency ultrasound imaging system to reconstruct high-resolution (<50 µm) 3D surface images of periodontal defects in human jawbone. The system employs single-element focused ultrasound transducers with center frequencies ranging from 30 to 60 MHz. Continuous acquisition using a 1 GHz data acquisition card is synchronized with a high precision two-dimensional positioning system of ±1 µm resolution for acquiring accurate measurements of the mandible, in vitro. Signal and image processing algorithms are applied to render 3D surface images of the jawbone. In vitro experiments were performed to assess the system performance using mandibles with teeth (dentate) or without (non-dentate). The system was able to reconstruct 3D images for the mandible's outer surface with superior spatial resolution down to 24 µm, and to perform the whole scanning in less than 30 s. All anatomical landmarks were detected and fully described as 3D images using this novel ultrasound imaging technique, whereas the 2D X-ray radiographic images suffered from poor contrast.