cone beam international magazine of cone beam dentistry

I 33 technique _ neuromuscular application I cone beam2_2014 lateral avascular necrosis, as seen here in the bilat- eralcoronalviews (Fig. 16), an arte- fact with invasive consequences! The operator should have con- tinuedtoFigure13, and using the ob- liqueorpanoramictool,drawnthenecessaryBezier curve incorporating both lateral and medial poles (Fig. 17). _Soft-tissue legalities There has been a great deal of discussion and unwarranted fear being disseminated by a few self serving oral and maxillofacial radiologists in addi- tion to the manufacturers of smaller FOV systems. Implying that we are now responsible for diagnos- ing brain tissue! Three-dimensions do not change the fact that brain tissue maladies and diagnoses are not taught indentalschoolandthatCBCTsystemsbytheirvery nature are not to be used in lieu of a medical CT or MRI for soft-tissue diagnoses. With the cephalograms I read, an image encom- passingmorecranialanatomythanthetypicallarge FOVCBCTscan,Iseeoneortwofibrosarcomainsella andthethyroideverymonthbecauseIlookforthem. But I see few articles in our dental journals that address these very issues, and I suspect that our medical radiology journals also devote little ink to periodontal disease. A review of the current literature suggests: “Incomparingcone-beamtechnologywithcon- ventional CT, it should be kept in mind that cone beam systems dedicated to maxillofacial diagnos- tics by their physical nature do not provide enough low-contrast resolution to discriminate soft tissue structures.”2 “Where it is likely that evaluation of soft tissues will be required as part of the patient’s radiological assessment, the appropriate imaging should be conventional medical CT or MR, rather than CBCT... Statement 8 comes close to this in recom- mending that CBCT not be used where soft tissue assessment is a significant aspect of the need for imaging.”3 _Conclusions CBCT has been responsible for a significant reduction in radiation as compared to medical CT (68µSvvs.1200–3300µSv4).OneCBCTscanisequi- valent to approximately five plain film panoramic radiographs, significantly less than a full-mouth series. CBCT images can be saved and viewed as native DICOM, PDF and JPEG compressed files and imported into most third-party patient manage- ment software programs. As a result of this evolution, there are now numerous free DICOM 3-D multiview readers avail- able5 for both PC and Mac platforms, yet this author prefers the Anatomage InvivoTM 3-D software7 for its ease of use and options. CBCT has also been re- sponsibleformakingCTtechnologyaffordablewhile opening up paths for future research and innova- tion, particularly in neuromuscular orthopaedics._ Editorial note: a complete list of references is availablefromthepublisher. Fig. 18_CT brain CBCT axial scan. Fig. 19_Normal axial medical CAT scan. Fig. 20_Brain stereograms. Dr Greenan is an internationally known X-ray authority and president of Imaging Systems Inc., theAcademy forAdvanced Radiographic Studies,author ofA PracticalAtlas ofTMJ and Cephalometric Radiology and has published in numerous journals and textbooks on dental implants,orthodontics andTMJ radiology. RichardW.Greenan c/o Imaging Systems Inc. Ste.#100–104 111 Petrol Point Peachtree City,Ga.30269,USA dick@goodxrays.com cone beam_author Fig. 20Fig. 19Fig. 18