High-Resolution 3D Ultrasound Jawbone Surface Imaging for Diagnosis of Periodontal Bony Defects: An In Vitro Study AHMED M. MAHMOUD, 1,2 PETER NGAN, 3 RICHARD CROUT, 4 and OSAMA M. MUKDADI 1,5 1 Department of Mechanical and Aerospace Engineering, West Virginia University, P.O. Box 6106, Morgantown, WV 26506-6106, USA; 2 Department of Biomedical Engineering, Cairo University, Giza 12613, Egypt; 3 Department of Orthodontics, West Virginia University, Morgantown, WV, USA; 4 Department of Periodontics, West Virginia University, Morgantown, WV, USA; and 5 Center for Cardiovascular and Respiratory Sciences, West Virginia University, Morgantown, WV, USA (Received 25 January 2010; accepted 26 May 2010) Associate Editor James Tunnell oversaw the review of this article. Abstract—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 lm) three-dimensional (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 acqui- sition using a 1 GHz data acquisition card is synchronized with a high-precision two-dimensional (2D) positioning sys- tem of ±1 lm resolution for acquiring accurate measurements of the mandible, in vitro. Signal and image processing algorithms are applied to reconstruct high-resolution ultra- sound images and extract the jawbone surface in each frame. Then, all edges are combined and smoothed in order to render a 3D surface image of the jawbone. In vitro experiments were performed to assess the system performance using mandibles with teeth (dentate) or without (nondentate). The system was able to reconstruct 3D images for the mandible’s outer surface with superior spatial resolution down to 24 lm, and to perform the whole scanning in <30 s. Major anatomical landmarks on the images were confirmed with the anatomical structures on the mandibles. All the anatomical landmarks were detected and fully described as 3D images using this novel ultrasound imaging technique, whereas the 2D X-ray radio- graphic images suffered from poor contrast. These results indicate the great potential of utilizing high-resolution ultra- sound as a noninvasive, nonionizing imaging technique for the early diagnosis of the more severe form of periodontal disease. Keywords—Jawbone assessment, High-frequency ultrasound, Periodontal disease. INTRODUCTION Virtually every one, whether from the western or eastern countries, may suffer from some kind of dental disease. Dental disease can be defined as disease which affects the teeth or gums. It has been reported that more than 75% of Americans over 35 have some form of gum disease. 20 The National Oral Health Surveil- lance System (NOHSS) indicated that more than 20.5% of adult American citizens lost all of their teeth by age of 65+ years old due to tooth decay or gum disease. Furthermore, about 45.9% of adult American citizens aged 65+ have lost at least six teeth due to the same reasons. 4 Periodontal disease, which is an infection of the tis- sues that support the teeth, is one of the most pervasive dental diseases in the elderly adults. The more severe type, periodontitis, can be defined as the presence of gum or gingival inflammation at sites where there has been a pathological detachment of the connective tissue fibers from the cementum or outside covering of the root. In addition, inflammatory events also lead to the resorption or loss of the tooth supporting bone. 1 If not treated, this process can bring about the loss of the tooth. Additionally, this periodontal inflammation has been linked to other disease conditions including heart disease, stroke, adverse pregnancy outcomes, 2 and most recently cognitive loss. 34 Treatment approaches sug- gested by the American Academy of Periodontology include patient education encompassing training in personal oral hygiene, the removal of bacterial plaque by scaling and root planning and if necessary, surgical intervention by dentists. 14 The periodontal pathological changes that occur in the jawbone or alveolar bone are significant because Address correspondence to Osama M. Mukdadi, Department of Mechanical and Aerospace Engineering, West Virginia University, P.O. Box 6106, Morgantown, WV 26506-6106, USA. Electronic mail: sam.mukdadi@mail.wvu.edu; URL: http://www.mae.cemr.wvu.edu Annals of Biomedical Engineering (Ó 2010) DOI: 10.1007/s10439-010-0089-0 Ó 2010 Biomedical Engineering Society