Indikace snõâmkuê Cone Beam CT. Souborny referaât. Indications for Cone Beam CT. Systematic review.

Transcription

1 Indikace snõâmkuê Cone Beam CT. Souborny referaât. Indications for Cone Beam CT. Systematic review. MUDr. Daniela HlousÏ kovaâ, MUDr. Hana TycovaÂ, MUDr. Josef KucÏ era Ortodonticke oddeï lenõâ Stomatologicke kliniky 1. LF UK a VFN Praha Department of Orthodontics, Clinic of Stomatology, 1st Medical Faculty of Charles University and General University Hospital (VFN), Prague U vod I kdyzï bylo CBCT (Cone Beam computerized tomography) prïedstaveno jizï prïed cï tvrt stoletõâm, teprve v poslednõâ dekaâ deï se podarïilo vyvinout systeâ m prïimeï rïenyâ ch rozmeï ruê a zaâ rovenï cenoveï dostupnyâ, kteryâ je pouzï itelnyâ i v ortodontickyâ ch praxõâch. OrtodontistuÊ m poskytuje pro diagnoâ zu a stanovenõâ leâcï ebneâ ho plaâ nu nejen zobrazenõâ dvojdimenzionaâ lnõâ (2D), ale zejmeâ na zobrazenõâ trojdimenzionaâ lnõâ (3D) [1]. TeÏ chto mozïnostõâ se v ortodoncii s vyâ hodou vyuzïõâvaâ k detailnõâmu zjisïteï nõâ polohy retinovanyâ ch zubuê, k objasneïnõâ mozïnyâ ch resorpcõâ korïenuê prïilehlyâ ch zubuê, u asymetriõâ oblicï ejoveâ ho skeletu, prïõâpadneï u parodontologickyâ ch pacientuê s insuficiencõâ kosti [2]. PrÏõÂchod CBCT muê zïe prïislõâbit i dokonalejsï õâ 3D kefalometrickou analyâ zu [3]. KromeÏ toho CBCT vysï etrïenõâ nachaâ zõâ svoje mõâsto i v implantologii a v maxilofaciaâ lnõâ chirurgii [2]. Nespornou vyâ hodou CBCT v porovnaâ nõâ s FBCT (Fan Beam computerized tomography) je, zïe je prïesneïjsï õâ, skenovacõâ cï as je kratsïõâ, je znacïneï levneïjsï õâ a zejmeânamaâ mnohem mensïõâdaâ vku zaârïenõâ [4] (Ortodoncie 2012, 21, cï. 4, s ). Introduction Though Cone Beam Computerized Tomography (CBCT) had been introduced twenty five years ago, the appropriate and available system applicable also in orthodontic practice was developed only in the last decade. CBCT provides orthodontists with two-dimensional (2D) as well as three-dimensional (3D) imaging which helps in diagnostics and in preparing the treatment plan [1]. In orthodontics, CBCT is used to identify precisely the position of impacted teeth, to assess potential resorption of roots of adjacent teeth, and to evaluate facial skeletal asymmetries [2]. The insufficient bone in patients with periodontitis can be determined. CBCT can promise the better 3D cephalometric analysis [3]. It is also used in implantology and maxillofacial surgery [2]. In comparison with Fan Beam Computerized Tomography (FBCT), CBCT is more accurate, scanning process is shorter, it involves less radiation, so it is faster and safer for a patient, and it is also far less expensive [4] (Ortodoncie 2012, 21, No. 4, p ). Realita a CBCT CBCT je vsï eobecneï povazï ovaâ no za ªzlaty standardª pro diagnostiku v maxilofaciaâ lnõâ oblasti[5]. Ale zacï õânajõâ prïevlaâ dat iopacïneânaâ zory [6]. V roce 2010 vysï el v americkyâch novinaâ ch The New York Times cïlaânek, na jehozï zaâ kladeï se dostala do poveï domõâ spolecïnostiskutecï nost, zï e pouzïitõâ CBCT v ortodoncii je spojeno s radiacï nõâ zaâ teï zï õâ, kteraâ je pod tlakem marketingu prodejcuê rtg prïõâstrojuê podcenï ovaâ na [7]. Farman, prezident AAOMR (American Academy of Oral and Maxillofacial Radiology) poukazuje na nezbytnost ochrany Current situation and CBCT CBCT is generally considered a ªgolden standardª in maxillofacial diagnostics [5]. However, recently we witness an increased number of opposite views [6]. In 2010, The New York Times published an article focusing on the fact that the use of CBCT in orthodontics involves an amount of radiation which had been underestimated due to the efforts of marketing and false advertisements [7]. Farman, the President of the American Academy of Oral and Maxillofacial Radiology (AAOMR) underlines the need to protect against the radiation load involved 192

2 rocïnõâk21 prïed radiacïnõâzaâteïzïõâ spojenou s pouzïõâvaâ nõâm CBCT a to zejmeâna u deï tõâ, ktereâ jsou radiosenzitivneï jsï õâ [7]. Obavy vidõâ jako opodstatneï neâ, protozïe s prïõâchodem CT prïõâstrojuê do pediatrie dosï lo v minulosti k prïeexponovaânõâ deï tõâ. A podobnyâ trend nastaâvaâ iv soucï asneâ dobeï [8]. Za povsï imnutõâ stojõâ i cïlaâ nek Hujoela a kol., kterïõâ poukazujõâ na to, zï e velkeâ mnozï stvõâ studiõâ se zabyâvaâ orgaâ novyâ mi daâ vkamiu dospeï lyâ ch, zatõâmco veï tsï ina ortodontickyâ ch pacientuê jsou deï tia adolescenti. ZduÊ raznï ujõâ, zï e poloha orgaânuê u mladyâch lidõâ je odlisïnaâ. Pokud se neberou v uâ vahu vsï echny tyto odlisï nosti, muêzï e dochaâzet k chybneâ interpretaci zaâ veï ruê vyâ zkumuê, kdy vyâsledky studiõâ na dospeï lyâ ch budou pausï alizovaâ ny i na deï tskeâ pacienty. AutorÏicÏ laâ nku takeâ poukazujõâ na probleâm prïeexponovaânõâdeïtõâs prïõâchodem CT do medicõâny azaâ rovenï se obaâ vajõâ, zï e pod reklamnõâm tlakem zduê raznï ujõâcõâm nõâzkeâ daâ vky u CBCT prïõâstrojuê klinicï tõâleâ karïipodcenõâ skutecï neâ daâ vky u mladyâ ch lidõâ [8]. Proble m odpoveï dnosti DalsÏ õâprobleâ m, kteryâ se v soucï asneâ dobeï vynorïuje, se tyâkaâ odpoveï dnostiza hodnocenõâ CBCT zobrazenõâ. Patologicke uâ tvary z celeâ maxillofaciaâ lnõâ oblastiby meï l optimaâ lneï hodnotit radiolog a zpraâ vu posõâlat indikujõâcõâmu specialistovi (naprï. stomatologovicï iortodontistovi). SkutecÏ nost je ale takovaâ, zï e CBCT prïõâstroj muê zïe vlastnit jakyâ koliv specialista vcï etneï ortodontistuê a tak iinterpretace snõâmkuê zuê staâ vaâ na teï chto leâ karïõâch. Vzhledem k tomu, zïe se cï asto nejednaâ jen o zobrazenõâ dentice, je nutneâ, aby stomatologoveâ meï lidostatecï neâ veïdomostia zkusï enosti v oblasti anatomie a patologie hlavy a krku. Farman upozornï uje, zï e pokud nebude hodnotit CBCT zkusï enyâ leâ karï, muê zï e dojõât nejen k chybneâ interpretaci s naâ slednou neadekvaâ tnõâ leâ cï bou, ale ik prïehleâ dnutõâ ruê znyâ ch patologickyâ ch procesuê [9]. Organizace HPA (The Health Protection Agency ) ve Velke Brita nii doporucï uje, aby CBCT hodnotil bud' dostatecï neï zkusï enyâ a prosï kolenyâ stomatolog nebo aby poskytovatel CBCT vysï etrïenõâ zameï stnaâ val radiologa, kteryâ pro neï j bude CBCT hodnotit [10]. Podle Melsenove by 3D radiografie meï la byâ t soucï aâ stõâ vzdeï laâ vacõâho programu v ortodoncii [11]. K tomuto naâ zoru se prïiklaâ nõâ iscarfe [12]. V prïõâpadeï patologickyâchnaâ lezuê mimo dentici by se meï l ortodontista radit jesïteï s radiologem [11, 13]. Scarfe upozornï uje na to, zï e nenõâ neobvykleâ, zï e prïõâmo firmy, ktereâ distribuujõâ CBCT prïõâstroje, porïaâ dajõâ vzdeï laâ vacõâ kurzy (kde komercï nõâ zaâ jem prïevlaâ daâ nad zdravotnickyâ m). To vedlo k plaâ novaâ nõâ vzdeï laâ vacõâch kurzuê na firmaâ ch nezaâ vislyâ mi organizacemi. AAOMR (American Academy of Oral and Maxillofacial Radiology) je neziskovaâ organizace reprezentovanaâ maxilofaciaâ lnõâmi radiology v USA. Tato organizace prïedpoklaâ daâ, zïe vsï eobecnyâ nekomercï nõâ vzdeï laâ vacõâ kurz ohledneï CBCT by mohl byât zahaâ jen uzï v roce V podobneâm with CBCT especially in children who are more sensitive to radiation [7]. He points out the fact that after CT had been introduced in pediatrics, children were overly exposed to radiation. He can see the similar trend today connected to CBCT [8]. The article by Hujoel et al., emphasizes the fact that while a number of studies deal with radiation load in adults, most orthodontic patients are children and adolescents. The authors point out that organs are located differently in young people. If the differences are not taken into account, study results interpretations may be wrong (the results obtained in adults may be inappropriately applied to young children). They also mention the problem of children's over-exposure resulting from CT use in medicine, and they voice their worries about that the clinical physicians may underestimate real doses in young people due to the advertised low radiation load connected with CBCT [8]. Responsibility Another question is who is responsible for CBCT images interpretation. Pathological formations of maxillofacial area should be read by a radiologist who would then send the report to the specialist sending the patient (e.g. dentist or orthodontist). However, today CBCT equipment may own any specialist, orthodontists included, and thus images are interpreted by those physicians. With regard to the fact that very often the scan includes more than just a dentition image, it is necessary that dentists have sufficient knowledge and expertise in the anatomy and pathology of head and neck. Farman points out that in case CBCT is evaluated by a less experienced physician, the interpretation may be wrong, and various pathological processes may be unnoticed [9]. The Health Protection Agency (HPA), U.K., recommends that CBCT be evaluated by an experienced and trained dentist or a radiologist [10]. According to Melsen, 3D radiography should become a part of graduation curriculum for orthodontists [11]. The same view is voiced also by Scarfe [12]. In case of pathological findings outside dentition, an orthodontist should always consult a radiologist [11, 13]. Scarfe mentions that companies selling CBCT equipment often offer training programmes (with prevailing commercial interest). Similar courses are also organized by independent institutions. The American Academy of Oral and Maxillofacial Radiology (AAOMR) is a non-profit organization represented by U.S. maxillofacial radiologists. AAOMR assumes that a general non-commercial CBCT training course starts in Similar programmes are to be held also in the United Kingdom, Germany, Greece or in Denmark. Legislation should divide CT devices into two types: - With a small field of view (FOV), that may be operated by a dentist after he attended a short course. 193

3 rozsahu se bude konat iv jinyâch zemõâch, naprï. ve Velke Brita nii, NeÏ mecku, RÏ ecku, cï i Da nsku. Legislativnõ dodatek by meï l rozdeï li t CT prïõâstroje na 2 typy: - s malyâm FOV (field of view), kteryâ muêzïe obsluhovat istomatolog po absolvovaânõâneï kolikadennõâho kurzu - s velkyâm FOV, kteryâ bude dostupnyâ pro stomatology azï po uâ speï sï neâ interpretaci 50 prïõâpaduê za prïõâtomnostiorofaciaâ lnõâho radiologa [12] Zjistilo se, zïe prïipouzïõâvaâ nõâ CBCT vysï etrïenõâ se naâhodneï diagnostikuje veï tsï õâ mnozï stvõâ vedlejsï õâch patologickyâch naâ lezuê. Mezityto naâ lezy patrïõâ naprïõâklad naâhodneâ objevenõâ rozsïteï pu obratluê ( spina bifida ), cizõâho teï lesa v hornõâch dyâ chacõâch cestaâ ch, condylus bifidus temporomandibulaâ rnõâho kloubu [13]. Proto mõâra zodpoveï dnostiprïihodnocenõâ CBCT je vyâ znamnaâ. Je nutno prohleâ dnout celyâ zobrazovanyâ objem CBCT a nezameïrïovat se jen na oblast zaâ jmu. Vzhledem k nedostatecïneâ legislativeï semuêzïe staât,zïe budou stomatologoveâ v budoucnosticï elit zï alobaâ m z chybneâ interpretace CBCT snõâmkuê [11]. ZmeÏ ny vaâ hovyâ ch faktoruê pro jednotliveâ orgaâ ny Mezina rodnõâ komise radiologickeâ ochrany ICRP (International Commission on Radiological Protection) v roce 2007 opeï tovneï prïehodnotila tkaâ nï oveâ vaâ hoveâ faktory. Stimul k revizi hodnot tkaânï ovyâch vaâ hovyâch faktoruê vznikl na zaâ kladeï novyâ ch informacõâ o incidenci naâ doruê. V roce 1990, kdy se urcï ovaly tkaânï oveâ vaâ hoveâ faktory prïed revizõâ naposledy, nebyly tyto informace jesïteï dostupneâ.v teâ dobeï se jako riziko vzniku malignity zohlednï ovala jen mortalita. V roce 2007 se do tohoto rizika prïipocï õâtala icelkovaâ zaâteï zï onemocneï nõâ malignõâm naâ dorem ( morbidita ) tzn., zïe se zohlednily i ty typy naâ doruê, pro ktereâ je charakteristickeâ dlouhodobeâ prïezï itõâ. VeÏ tsï ina uâ dajuê pochaâ zõâ z dlouhodobeâ ho monitorovaâ nõâ osob, ktereâ prïezïili vyâbuch atomoveâ bomby v Japonsku. Na zaâ kladeï teï chto zjisïteï nõâ se usoudilo, zï e riziko vzniku malignõâho tumoru slinnyâch zïlaâ z a mozku je vysï sï õâ a byly jim prïirïazeny vysï sï õâ tkaâ nï oveâ vaâ hoveâ faktory [14]. Riziko vzniku malignity v orofaciaâ lnõâ oblasti vyplyâ vajõâcõâ z radiografickyâ ch vysï etrïenõâ hlavy a krku (vcï etneï CBCT a MSCT ) je tedy vysïsïõânezïsedrïõâveprïedpoklaâ dalo [12]. Ludlow a kol. konstatuje, zïe daâ vka prïi zhotovenõâ CBCT je sice vysïsï õâ nezï u konvencï nõâch radiologickyâ ch vysï etrïenõâ, ale na druheâ straneï je mnohem nizï sï õâ nezï u konvencï nõâ vyâ pocï etnõâ tomografie [14]. Naproti tomu dvojdimenzionaâ lnõâ vysï etrïenõâ je statickeâ a omezeneâ [11]. MozÏ nost volby ze sï irokeâ ho spektra pomocnyâ ch zobrazovacõâch metod vyzï aduje promysï lenou strategii vyâbeï ru vhodneâ ho zobrazovacõâho vysï etrïenõâ tak, aby byla dosazï ena pozï adovanaâ diagnostickaâ i n- formace s minimaâ lnõâminaâ klady a rizikem pro pacienta [15]. - With a big field of view (FOV) that may be operated by dentists only after they successfully evaluate 50 scans under the supervision of an orofacial radiologist [12]. It was found that during diagnosing with CBCT a number of pathological formations is discovered as a by-product. The findings include e.g. spina bifida, a foreign body within upper airways, condylus bifidus of temporomandibular joint [13]. Therefore, the responsibility of those who evaluate CBCT scans is extremely high. It is necessary to survey the whole CBCT content, and not to focus just on the area for which CBCT imaging was originally indicated. Due to the lack of legislature, dentists are at risk of being sued for misinterpretation of CBCT scans [11]. Change in weighted factors for individual organs of body In 2007 the International Commission on Radiological Protection (ICRP) re-evaluated tissue weighted factors. The stimulus for the re-evaluation resulted from the new information on tumour incidence. In 1990 when the tissue weighted factors were established prior to the recent re-evaluation, the information was not available. At the time only mortality was seen as the risk of malign tumours incidence. Since 2007 the risk involves also the overall morbidity, i.e. the tumours characterized by a long-time survival were included. Most data come from a long-time monitoring of survivors of atomic bomb explosion in Japan. The data led to the conclusion that the risk of salivary glands and brain tumours was higher, and therefore they were assigned higher tissue weighted factors [14]. Thus, the risk of malign tumours incidence in the orofacial area due to radiographic examination of head and neck (including CBCT and MSCT) is higher than previously suggested [12]. Ludlow et al. conclude that the dosage in CBCT is higher than in conventional radiological examinations; however, it is still lower than in conventional CT [14]. On the other hand, two-dimensional examination is static and limited [11]. Therefore, the choice of appropriate radiological examination requires a well-thought strategy aimed at the required diagnostic information obtained with minimum costs and risk for a patient [15]. Recommendation for CBCT in dental medicine During CBCT, the field of view (FOV) should cover only the area of interest (in order to decrease the radiation load). Therefore, craniofacial CBCT should be used only in rare cases [9]. We should not ignore the risks of radiographic imaging methods. In indication we should consider the proportion of utilization percentage and risk for individual imaging techniques 194

4 rocïnõâk21 DoporucÏ enõâ pro pouzïõâvaâ nõâ CBCT ve stomatologii PrÏizhotovova nõâ CBCT, by se meï la (v raâ mcisnõâzï enõâ daâ vek) zvolit velikost zobrazovaneâ ho pole ( FOV) tak, aby rozsahem odpovõâdala oblastizaâ jmu. Kraniofacia lnõâ CBCT je tedy vyhrazeno jen na ojedineï leâ prïõâpady [9]. Rizika radiografickyâ ch zobrazovacõâch metod by rozhodneï nemeï la byâ t ignorovaâ na. Za rovenï je nutneâ prïi indikaci jednotlivyâ ch zobrazovacõâch metod zvaâ zï it pomeï r vyâteï zï nosti/rizika pro danou zobrazovacõâ metodu a pacienta. PrÏimale vyâteï zï nostije mozï nost vzniku diagnostickeâ ho omylu a s tõâm naâ sledneï souvisejõâcõâ komplikace prïileâcïbeï. Jsou k dispozici stovky protokoluê pro ruê zneâ vysïetrïenõâ pomocõâ zobrazovacõâch metod. CÏ asto je rozhodnutõâ na radiologovi, nebo na radiologickeâ m asistentovi jakeâ technickeâ parametry pouzï ije. Idea lneï by meï ly byât tyto faktory vybraâ ny tak, aby se dosaâ hlo cõâle vysï etrïenõâ prïico mozïnaâ nejnizïsïõâdaâ vce zaârïenõâ. Realita je vsï ak obvykle takovaâ, zïe veï tsï ina CT prïõâstrojuê je nastavena od vyâ robce bez uvaâ zï enõâ optimalizace daâ vky/kvality a je na samotneâ m radiologovi jestli zvaâ zï õâ faktory, jimizï muêzïedaâ vku snõâzï it [16, 14]. HPA (The Health Protection Agency) vznikla ve Velke Brita nii jako nezaâ vislaâ organizace, kteraâ byla sestavena vlaâ dou v roce 2003, aby chraâ nila zdravõâ verïejnosti. Vzhledem ke zvysï ujõâcõâ tendencik pouzïõâvaânõâ CBCT ve Velke Brita nii se zacï ala zabyâvat iotaâ zkou CBCT ve stomatologii. ZverÏejnila tabulku daâ vek CBCT a panoramatickeâ ho snõâmku. Po zhodnocenõâ vyâ sledkuê prïichaâzõâ k zaâveï ru, zï e CBCT by nemeï lo nahradit panoramatickyâ a kefalometrickyâ snõâmek a jeho indikace by meïlabyât dobrïe zvaâzïena. KvuÊ livysïsï õâ radiacïnõâzaâteïzïi, nepovazï uje HPA za vhodneâ, aby bylo CBCT zhotovovaâ no vyâ hradneï za uâ cï elem rekonstrukce OPG a kefalometrickeâ ho snõâmku, pokud jsou tato vysï etrïenõâ sama o sobeï schopna poskytnout dostatecï nou informaci. Na druhou stranu pokud by bylo nutneâ zhotovit CBCT, tak k zõâskaâ nõâ OPG a kefalometrickeâ ho snõâmku se vyuzï ije rekonstrukcõâ z CBCT [10]. Evropske spolecï enstvõâ pro atomovou energii (European Atomic Energy Community,EAEC) si dalo za cõâl vypracovat projekt SEDENTEXCT (Safety and Efficacy of a New and Emerging Dental X-ray Modality) ( ). ZaÂmeÏ rem projektu je zõâskat co nejvõâce klõâcï ovyâch informacõâ o CBCT a urcï it alesponï provizornõâ smeï rnice a doporucï enõâ pro pouzï õâvanõâ CBCT ve stomatologii [17]. Po vypracovaâ nõâ projektu SEDENTEXCT v roce 2011 uverïejnilo EAEC doporucï enõâ pro pouzïõâvaâ nõâ CBCT ve stomatologii. Hlavnõ zaâ sady jsou [18]: -prïihodnocenõâ retinovanyâ ch zubuê a prïilehlyâ ch tkaâ nõâ, vcï etneï stanovenõâ prïõâtomnostiresorpce okolnõâch zubuê by se meï lo preferovat CBCT vysï etrïenõâ (vzhledem k jeho nizïsï õâ daâ vce) prïed MSCT (multislice CT). CBCT and for a patient. In case of a low utilization percentage, there is a risk of wrong diagnosis, and consequently complications during the treatment. There are hundreds of protocols for various examinations using imaging techniques. Often it is up to a radiologist or radiological assistant which technical parameters are used. Ideally, the factors should be chosen to accomplish the examination with the lowest radiation load possible. However, most CT devices are preset by a manufacturer without regard to optimum dosage/quality, and it is up to a radiologist to consider whether and how to reduce the radiation exposure [16, 14]. The Health Protection Agency (HPA) was established in Great Britain by the government in 2003 as an independent organization to protect public health. With regard to increasing use of CBCT in Great Britain, the organization deals also with the use of CBCT in dental medicine. HPA published the table of CBCT and OPG radiation dosage. They conclude that CBCT should not substitute OPG and cephalograms, and the CBCT indication should be always well grounded. With regard to higher radiation, HPA does not recommend to use CBCT only for the reconstruction of OPG and cephalograms in case the examinations supply sufficient information. On the other hand, if it is necessary to make CBCT, for OPG and cephalogram the reconstructions from CBCT should be used [10]. The European Atomic Energy Community (EAEC) aims to develop the project SEDENTEXCT (Safety and Efficacy of a New and Emerging Dental X-ray Modality) ( ). The project intends to obtain as much key information on CBCT as possible, and determine at least temporary guidelines and recommendations for the use of CBCT in dental medicine [17]. After completion of SEDENTEXCT in 2011 EAEC published the following recommendations [18]: - For assessment of impacted teeth and adjacent tissues, including detection of adjacent teeth resorption, CBCT should be preferred (with regard to lower radiation load) to MSCT (multislice CT). CBCT should be indicated only in case adequate information cannot be obtained by conventional radiography. When CBCT is indicated the field of view (FOV) should be as small as possible in order to reduce dosage. In case only craniofacial CBCT (with a large FOV) is at the disposal, the examination should be thoroughly considered. - In patients with cleft, CBCT is preferred to MSCT; FOV should cover only the area of interest. - CBCT is not usually indicated for introduction of temporary anchorage. - CBCT involving a large FOV should not become a routine in common orthodontic diagnostics 195

5 se muêzï e indikovat, jen pokud se nezõâskaâ adekvaâ tnõâ informace z konvencï nõâ radiografie, kteraâ maâ mnohem mensï õâ daâ vku zaâ rïenõâ. V prïõâpadeï rozhodnutõâ o CBCT vysï etrïenõâ by se meïlo v raâ mciredukce daâ vky pouzïõât co nejmensï õâ zobrazovaneâ pole ( FOV), ktereâ zobrazõâ jen oblast zaâ jmu. Pokud jsou k dispozici jen kraniofaciaâ lnõâ CBCT (s velkyâm FOV ), meïlobybyât rozhodnutõâ o provedenõâ vysï etrïenõâ pecï liveï zvaâ zï eno. - u rozsïteï povyâch pacientuê se dõâky mensïõâdaâ vce daâvaâ prïednost CBCT prïed MSCT, prïicï emzï by FOV meï lo odpovõâdat velikosti oblasti kteraâ maâbyât zobrazena - CBCT nenõâ normaâ lneï indikovaâno v prïõâpadeï zavaâdeï nõâ docï asnyâ ch kotevnõâch zarïõâzenõâ - CBCT s velkyâm FOV by se nemeï lo rutinneï pouzï õâvat v beïzïneâ ortodontickeâ diagnostice - kraniofaciaâ lnõâ CBCT je uprïednostnï ovaâno prïed MSCT u skeletaâ lnõâch deformit hlavneï pokud se jednaâ o ortodonticko-chirurgickyâ prïõâpad - CBCT nenõâ indikovaâ no k diagnostice kazuê - CBCT by se nemeï lo rutinneï pouzï õâvat k hodnocenõâ stavu periodontaâ lnõâ kosti ani k diagnostice parodontaâ l- nõâch patologickyâ ch procesuê. V prïõâpadech, kdy konvencï nõâ radiografie neposkytne potrïebneâ informace ke zhodnocenõâ furkacõâ a jinyâ ch parodontaâ lnõâch defektuê, muêzï e se pouzïõât CBCT s vysokyâm rozlisï enõâm, ale malyâm FOV. Naopak pokud CBCT vysï etrïenõâ zobrazuje izuby, meï la by se zkontrolovat iuâ rovenï prïilehleâ kostia vyâ skyt prïõâpadnyâ ch parodontaâ lnõâch patologickyâ ch procesuê. Limitovane CBCT s velkyâm rozlisï enõâm se muêzïe pouzïõâtke zhodnocenõâ parodontaâ lnõâch procesuê, pokud konvencï nõâ radiografie poskytla negativnõâ vyâ sledek a je prïõâtomnaâ klinickaâ symptomatologie - CBCT se nemaâ rutinneï pouzïõâvat k objasneï nõâanatomie korïenovyâ ch kanaâ lkuê. Jen v omezenyâ ch prïõâpadech se muêzï e pouzï õât limitovaneâ CBCT s vysokyâm rozlisï enõâm a to naprï. u võâcekorïenoveâ ho zubu, kde je nejasnaâ anatomie korïenovyâ ch kanaâ lkuê,daâ le v prïõâpadech resorpce korïene zaâneï tliveâ ho charakteru, cï ivnitrïnõâho granulomu (kde trojdimenzionaâ lnõâ zobrazenõâ poskytne informaci o prognoâ ze zubu), perforace, atypickeâ anatomie pulpy nebo v prïõâpadeï kombinovaneâ pulpoparodontaâ lnõâ leâ ze, kteraâ komplikuje endodontickou leâcïbu - limitovaneâ CBCT s vysokyâm rozlisï enõâm muêzïe byât indikovaânovprïõâpadech fraktur korïene zubu, kde konvencï nõâ intraoraâ lnõâ snõâmky neposkytly dostatecï nou informaci - CBCT muê zï e byâ t indikovaâ no v prïõâpadech, kdy konvencï nõâ radiografie prokaâzïe teï snou souvislost mezi trïetõâm molaâ rem a mandibulaâ rnõâm kanaâ lem, aby se detailneï objasnila jeho poloha prïed chirurgickyâm zaâ krokem - pokud konvencï nõâ radiografie neposkytne dostatecï neâ informace o retinovanyâ ch zubech, muê zï e byâ t indikovaâ no CBCT - Craniofacial CBCT is preferred to MSCT in case of skeletal deformities, especially in patients with orthognathic surgery - CBCT is not indicated for caries diagnostics - CBCT should not become a routine method for the assessment of periodontal bone condition, or for diagnostics of periodontal pathological processes. In case where conventional radiography does not bring information required for the assessment of furcations and other periodontal defects, CBCT with high resolution and small FOV may be used. On the contrary, when CBCT describes teeth, the level of adjacent bone should be examined as well as eventual periodontal pathological processes. Limited CBCT with high-resolution may be used to evaluate periodontal processes in case conventional X-rays brought negative results whilst there are clinical symptoms still present. - CBCT should not become a routine to clarify anatomy of root canals. Only sporadically a limited CBCT with high resolution may be used, e.g. in tooth with multiple roots where there is unclear anatomy of root canals, in case of inflammatory resorption of root, or in inner granuloma (3D imaging provides information on tooth prognosis), perforation, atypical anatomy of the pulp, or in case of a combined pulp-periodontal lesion which complicates endodontic treatment. - Limited CBCT with high resolution may be indicated in root fractures in case conventional intraoral X- ray pictures did not provide sufficient information. - CBCT may be indicated in cases when conventional radiography proves close relation between third molar and mandibular canal, in order to detail its position prior to surgery - CBCT may be indicated in case when conventional radiography did not bring sufficient information on impacted teeth - In planning before implants insertion, CBCT is preferred (due to lower radiation) to other techniques allowing for imaging of jaws in cross-section (e.g.msct) - multislice CT (MSCT) and magnetic resonance (MR) is preferred to CBCT in cases when evaluation of soft tissues is required - CBCT may be used in orofacial carcinoma when there is suspect invasion of tumor into jaw bones, and MSCT together with MR did not brig sufficient information on diagnosis and the stage of the illness - CBCT is preferred to MSCT in case of orofacial traumas when cross-section images are necessary whilst pictures of soft tissues are not - CBCT may be used in case of planning orthognathic surgery when skeletal three-dimensional imaging is required - When CT is indicated to describe TMK, CBCT is preferred over MSCT due to lower radiation load. 196

6 rocïnõâk21 -prïiplaâ novaâ nõâ prïed zavedenõâm implantaâ tuê se daâ vaâ CBCT prïednost (jako alternativeï s nizïsï õâmi daâ vkami) prïed jinyâ mimetodami, ktereâ umozï nï ujõâ zobrazenõâ cï elistõâ vprïõâcïnyâch rïezech (jako je naprï. MSCT) - tam, kde je nutneâ zhodnocenõâ meï kkyâ ch tkaâ nõâ v raâ mci radiologickeâ ho vysï etrïenõâ, se daâ vaâ prïednost MSCT a magnetickeâ resonanci(mr) prïed CBCT - u karcinomuê orofaciaâ lnõâ oblasti, kde je podezrïenõâ na invazi do cï elistnõâch kostõâ a MSCT spolu s MR neposkytly dostatecï nou informaci o diagnoâ ze a stadiu onemocneïnõâ,semuêzïe zhotovit CBCT - v prïõâpadech orofaciaâ lnõâch traumat, kde je potrïebneâ zobrazenõâ v prïõâcï nyâch rïezech a nenõâ potrïebneâ zobrazenõâ meï kkyâch tkaânõâ,semuêzï e kvuê linizïsïõâdaâ vce daâtprïednost CBCT prïed MSCT - CBCT se muêzïe zhotovit v prïõâpadeï plaâ novaâ nõâ ortognaâ tnõâ operace, kde je potrïebneâ trojdimenzionaâ lnõâ zobrazenõâ skeletu - pokud je pro zobrazenõâ TMK indikovaâ no CT, je kvuê limensï õâ daâ vce zaâ rïenõâ uprïednostnï ovaâ no CBCT prïed MSCT ZaÂveÏr Obrovsky rozmach pouzïõâvaâ nõâ CBCT v ortodoncii vedl Kokiche k zamysï lenõâ, zda prïinese 3D zobrazenõâ v ortodoncii skutecï neï vzï dy prospeï ch. Kokich jej povazï uje za naâ pomocneâ u ektopickyâ ch erupcõâ, retinovanyâ ch zubuê a transpozicõâ, kde umozï nõâ prostoroveâ zobrazenõâ a zjednodusï õâ diagnoâ zu. Pochybuje vsï ak o tom, zï e se pomocõâ CBCT zlepsïõâ leâcï ebnyâ vyâsledek ubeïzïnyâch anomaâliõâ.ocï em nenõâ pochyb je skutecï nost, zï e je toto vysï etrïenõâ pro pacienta financï neï naâ kladneï jsï õâ. CBCT jisteï pomuê zï e pochopit zmeï ny po ortognaâ tnõâch operacõâch, protozïe v teï chto prïõâpadech skutecïneï dochaâ zõâ k prostorovyâm zmeïnaâ m. Kokich ale varuje prïed nadmeï rnyâ m pouzï õâvaâ nõâm (zneuzï õâvaâ nõâm) CBCT praâ veï v teï chto studiõâch, kde pacienti absolvovali i 3 CBCT vysï etrïenõâ beï hem jednoho roku. Jako prvnõâ doporucï uje polozï it si otaâ zku, zda zõâskanyâ prospeï ch ze zhotovenõâ trojdimenzionaâ lnõâho vysï etrïenõâ skutecï neï prïevaâ zï õâ potencionaâ lnõâ riziko pro pacienta. ZodpoveÏ dnost je urcï i teï na naâ s, na indikujõâcõâch leâ karïõâch [6]. Z etickeâ ho hlediska je leâ karï povinen jednat v nejlepsï õâm zaâ jmu pacienta i v dlouhodobeâ m horizontu. Je-li jizï CBCT vysï etrïenõâ provedeno, meï lo by byâ t sdõâleno jak v raâ mci interdisciplinaâ rnõâ spolupraâ ce v raâ mcizubnõâho leâ karïstvõâ, tak i mezi specialisty jinyâch oboruê. Conclusion The enormous boom of CBCT use in orthodontics inspired Kokich to reflect on whether 3D imaging may be a real benefit in everyday orthodontics. Kokich believes it is useful in case of ectopic eruptions, impacted teeth and transpositions, as it allows for spatial imaging and simple diagnotics. Nevertheless, he doubts about the influence of CBCT on the better result of treatment in most malocclusions. There is no doubt that the examination is financially more demanding for a patient. CBCT helps to understand the changes occurring after orthognathic surgery because there really are spatial changes observed. However, Kokich warns against excessive use (or abuse) of CBCT in these studies - patients underwent as many as three CBCT examinations within one year. He suggests that first we should ask whether the benefit from 3D examination really outweighs potential risks for a patient. The responsibility is undoubtedly in our hands, in the hands of those who indicate patients for the examination [6]. Health care professional is responsible from the ethical point of view to behave in the best interest of patient also in the long term perspective. In the case the CBCT is performed, it should be shared in the interdisciplinary cooperation in dentistry, and with the other specialists in medicine as well. 13. rocïnõâk JihocÏeskyÂch ortodontickyâch dnuê ¹PolyteÂmatikaª ve dnech 26. a vcï eskyâch BudeÏjovicõÂch v hotelu Maly pivovar. Kontaktnõ adresa: MUDr. Milada HaÂlkovaÂ, VaÂclavska 282, Strakonice, tel.: , halek@iol.cz 197

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