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32 I I research _ CBCT roots4_2010 _Two-dimensional imaging modalities have been used in dentistry since the first intra-oral radiograph was taken in 1896. Significant progress in dental im- aging techniques has since been made, including panoramic imag- ingandtomography,whichenable reduced radiation and faster pro- cessing times. However, the imag- ing geometry has not changed with these commonly used intra- oral and panoramic technologies. Cone-beam computed tomog- raphy (CBCT) is a new medical imaging technique that generates 3-D images at a lower cost and absorbed dose compared with conventional computed tomog- raphy (CT). This imaging technique is based on a cone-shaped X-ray beam centred on a 2-D detector that performs one rotation around the object, producing a series of 2-D images. These images are re-constructed in 3-D using a mo- dification of the original cone-beam algorithm developed by Feldkamp et al. in 1984.1 Images ofthecraniofacialregionareoftencollectedwith a higher resolution than those collected with a conventional CT. In addition, the new systems are more practical, as they come in smaller sizes.2 Today, much attention is focused on the clinical applications—diagnosis, treatment and follow-up—of CBCT in the various dental disci- plines. The goal of the following systemic review is to review the available clinical and scientific literature pertaining to different clinical appli- cation of CBCT in the dental practice. _Materials and methods Clinical and scientific literature discussing CBCT imaging in dental clinical applications was reviewed. A MEDLINE (PubMed) search from 1 January 1998 to 15 July 2010 was conducted. Cone-beam computed tomography in dentistry was used as key phrase to extend the search to all the various dental disciplines. The search re- vealed 540 papers that were screened in detail. Owing to a lack of relevance to the subject, 406 papers were excluded. Thus, the systemic review consisted of 134 clinically relevant papers, which were analysed and categorised (Table I). _Analysis Oral and maxillofacial surgery CBCTenablestheanalysisofjawpathology,3–11 the assessment of impacted teeth (Fig. 1), super- numerary teeth and their relation to vital struc- tures,6,12–21 changes in the cortical and trabecular bone related to bisphosphonate-associated os- teonecrosis of the jaw5,22–23 and the assessment of bone grafts.24 It is also helpful in analysing and assessing paranasal sinuses6,25 and obstructive sleep apnea.27–28 As the images are collected from many dif- ferent 2-D slices, the system has proven its superiority in overcoming superimpositions and calculating surface distances.28–29 This advantage made it the technique of choice in mid-face frac- ture cases,30–31 orbital fracture assessment and management32 and for inter-operative visualisa- tion of the facial bones after fracture.33–34 Since it is not a magnetic resonance technique, it is the bestoptionforintra-operativenavigationduring procedures, including gun-shot wounds.35–36 Fig. 1_Impacted teeth in close proximity to vital structures should be evaluated with CBCT. Figs. 2a & b_Peri-apical lesion shown as peri-apical radiograph (a) and CBCT (b; images courtesy of Dr Fred Barnett). CBCTapplications in dental practice:Aliterature review Authors_ Dr Mohammed A. Alshehri, Dr Hadi M. Alamri & Dr Mazen A. Alshalhoob, Saudi Arabia Fig. 1 Fig. 2a Fig. 2b