ortho - the international C.E. magazine of orthodontics

ortho1_2012 Fig. 12_The 3-D rendering showing supernumersary teeth and positions. Fig. 13_The 3-D rendering with periodontal defects and calculus bridge. I 09 C.E. article_ application of 3-D imaging I trauma. The use of CBCT with MPRs and 3-D images reduces any guessing as well as the chance for any permanentdamagetothepatient.Withtheadoption ofCBCT,thejudgmentisbasedonsolidevidenceand the risk will decrease. A panorex of the superimosed third molars gave nosolidevidencethecanalliesbetweentheroots.Itis onlywiththeuseofCBCTandtheMPRsthatthenerve canaccuratelybeseentraversingbetweenthemesial buccal and mesial lingual root (Fig. 11).4,5 Other surgical advantages include the identifica- tion and the position of supernumerary or impacted teeth.Theimagesshowaccuratepositionsandshow definitive morphology that will aid in removal of the proper teeth (Fig. 12). Knowing the exact position of manyoftheseteethisabenefittoboththedoctorand patient. It will lead to the most precise surgical path and the least invasive procedure. _Periodontics The explanation of periodontal problems are often misunderstood by the patient. As doctors, we talk about pockets, point to X-rays and propose treatment only to have patients refuse treatment because they do not understand what we are clini- cally describing. Using the 3-D portion of the CBCT scancanimprovetheunderstandingandacceptance of treatment plans. The images are a picture of the problem that is ownedbythatpatientandmucheasiertounderstand bythelayperson.Illustratingperiodontaldefectsand pocketsallowsthepatienttobetterparticipateinthe process (Fig. 13). The MPRs and the 3-D projections aid in surgical planning for periodontists, allowing for accurate measurements and bone analysis prior to osseous surgerythatdoctorscannotgetusingtheperiapicals or panoramics. Studies have shown that CBCT images are more accuratethanpanoramicradiographs.Fortheperio- dontistplacingimplants,theabilitytomeasurebone densityandavoidimportantanatomyisimportant.4,5 _Orthodontics Orthodontists are beginning to adopt large field- of-view CBCT. Recent studies show that linear measurementsofbonystructuresaremoreaccurate using CBCT and have less distortion than current methods of measurement: lateral cephalometric, posteroanterior (PA) and submentovertex (SMVT).5 Accurate measurements of tooth volume and tooth position can aid in accelerated treatment times and more precise treatment. Along with tooth position, density of bone and size of arches, the orthodontist also has an accurate evaluation of the temporomandibular joint and position of the condyles. Impacted teeth are easily identified and position, either buccal or lingual can be confirmed prior to movement or removal. BothMPRsand3-Dprojectionsgivethecliniciana complete picture of the problems and the treatment course. With a single CBCT scan, orthodontists can pro- duce all of the information they need: panoramic, cephalometric, PA, SMVT, tooth size and volume, crowding evaluation in any plane, TMJ evaluation Fig. 12 Fig. 13