Objective The purpose of this study was to evaluate an ultrasound mucous-membrane-thickness-measuring device as a noninvasive, nonionizing alternative to radiography in the assessment of alveolar bone grafting. Design This was a prospective experimental study on porcine cadaver models. Method An ultrasound technique (Krupp SDM) was assessed ex vivo on three specially developed porcine cadaver models in comparison to radiography and ridge-mapping. Direct measurement of the mucosal thickness provided a standard for comparison. In each model, 30 measurement sites were identified for comparison of the techniques. Results All measurement techniques demonstrated clinically acceptable re-producibility. Of the clinical measurement techniques, radiography proved to be the most reliable, showing a small, nonsignificant statistical difference from direct measurement. Both the ultrasound technique and ridge-mapping showed significant tendencies to underestimate mucosal thickness that became greater with increasing mucosal thickness. At sites where mucosal thickness was less than 6 mm, the ultrasound technique underestimated mucosal thickness by 0.6 mm on average. At sites where mucosal thickness exceeded 6 mm, ultrasonic artifacts rendered the ultrasound technique unreliable. Conclusion The ultrasound technique could prove to be a useful clinical adjunct to radiography in the assessment of alveolar bone grafts, but in this particular application, care should be taken when using it to assess deeper alveolar defects.
Numerical Simulation of the Aerosol Particle Motion in Granular Filters with Solid and Porous Granules
