Simulations of Ultrasonographic Periodontal Probe Using the Finite Integration Technique

Abstract

Periodontal disease is one of the most pervasive dental diseases in older adults. It involves the loss of connective tissue attachment with subsequent destruction of tooth- supporting bone, leading to loss of teeth. Periodontal pocket depth is currentlymeasured with an invasive manual probe, but adapting diagnostic ultrasound to this purpose can avoid the pain and inaccuracy inherent in manual probing. In this paper, 3D simulations of ultrasonic periodontal probe measurements are described, using a parallel finite integration technique which is adaptable enough to create realistic anatomical geometries. The outputs of the simulation include 3D pressure values distributed throughout the periodontal anatomy, 2D vertical cross sections of the acoustic pressure waves, and the pressure across the face of the transducer which is used to synthesize the ultrasonic echo. Experimental comparison with a simple phantom is also shown. Lastly, the energy values for different simulations are calculated from the 3D pressure values to describe the amount of energy reaching different zones, especially the junctional epithelium. The simulations as well as the energy studies show that only a small portion of the ultrasonic energy is reaching the junctional epithelium, and so sophisticated mathematical techniques are required to ultrasonicallymeasure pocket depth.