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

Indikace snõÂmkuÊ Cone Beam CT. Souborny referaÂt.

Indications for Cone Beam CT. Systematic review.

MUDr. Daniela HlousÏkovaÂ, MUDr. Hana TycovaÂ, MUDr. Josef KucÏera Ortodonticke oddeÏlenõ 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

UÂvod

I kdyzÏbylo CBCT (Cone Beam computerized tomography) prÏedstaveno jizÏprÏed cÏtvrt stoletõÂm, teprve v poslednõ dekaÂdeÏ se podarÏilo vyvinout systeÂm prÏimeÏrÏenyÂch rozmeÏruÊ a zaÂrovenÏ cenoveÏ dostupnyÂ, ktery je pouzÏitelny i v orto-dontickyÂch praxõÂch. OrtodontistuÊm poskytuje pro diagnoÂzu a stanovenõ leÂcÏebneÂho plaÂnu nejen zobrazenõ dvoj-dimenzionaÂlnõ (2D), ale zejmeÂna zobrazenõ trojdvoj-dimenzionaÂlnõ (3D) [1].

TeÏchto mozÏnostõ se v ortodoncii s vyÂhodou vyuzÏõÂva k detailnõÂmu zjisÏteÏnõ polohy retinovanyÂch zubuÊ, k objasneÏnõ mozÏnyÂch resorpcõ korÏenuÊ prÏilehlyÂch zubuÊ, u asymetriõ oblicÏejoveÂho skeletu, prÏõÂpadneÏ u parodontologickyÂch pacientuÊ s insuficiencõ kosti [2]. PrÏõÂchod CBCT muÊzÏe prÏislõÂbit i dokonalejsÏõ 3D kefalometrickou analyÂzu [3]. KromeÏ toho CBCT vysÏetrÏenõ nachaÂzõ svoje mõÂsto i v implantologii a v maxilofaciaÂlnõ chirurgii [2]. Nespornou vyÂhodou CBCT v porovnaÂnõ s FBCT (Fan Beam computerized tomography) je, zÏe je prÏesneÏjsÏõÂ, skenovacõ cÏas je kratsÏõÂ, je znacÏneÏ levneÏjsÏõ a zejmeÂna ma mnohem mensÏõ daÂvku zaÂrÏenõ [4](Ortodoncie 2012, 21, cÏ. 4, s. 192-198).

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 resorp-tion 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. 192-198).

Realita a CBCT

CBCT je vsÏeobecneÏ povazÏovaÂno za ªzlaty stan-dardª pro diagnostiku v maxilofaciaÂlnõ oblasti[5]. Ale zacÏõÂnajõ prÏevlaÂdat iopacÏne naÂzory [6]. V roce 2010 vy-sÏel v americkyÂch novinaÂch The New York Times cÏlaÂ-nek, na jehozÏ zaÂkladeÏ se dostala do poveÏdomõ spolecÏ-nostiskutecÏnost, zÏe pouzÏitõ CBCT v ortodoncii je spo-jeno s radiacÏnõ zaÂteÏzÏõÂ, ktera je pod tlakem marketingu prodejcuÊ rtg prÏõÂstrojuÊ podcenÏovaÂna [7]. Farman, prezi-dent AAOMR (American Academy of Oral and Maxillo-facial Radiology) poukazuje na nezbytnost ochrany

Current situation and CBCT

CBCT is generally considered a ªgolden standardª in maxillofacial diagnostics [5]. However, recently we wit-ness 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

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 dif-ferences are not taken into account, study results inter-pretations 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 underesti-mate 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 ma-xillofacial 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, to-day CBCT equipment may own any specialist, ortho-dontists 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 evalua-ted 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 be-come 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 Ame-rican 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 2011. 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 ope-rated by a dentist after he attended a short course. prÏed radiacÏnõÂ zaÂteÏzÏõÂ spojenou s pouzÏõÂvaÂnõÂm CBCT a to

zejmeÂna u deÏtõÂ, ktere jsou radiosenzitivneÏjsÏõ [7]. Obavy vidõ jako opodstatneÏneÂ, protozÏe s prÏõÂchodem CT prÏõÂ-strojuÊ do pediatrie dosÏlo v minulosti k prÏeexponovaÂnõ deÏtõÂ. A podobny trend nastaÂva iv soucÏasne dobeÏ [8]. Za povsÏimnutõ stojõ i cÏlaÂnek Hujoela a kol., kterÏõ pouka-zujõ na to, zÏe velke mnozÏstvõ studiõ se zabyÂva orgaÂno-vyÂmidaÂvkamiu dospeÏlyÂch, zatõÂmco veÏtsÏina ortodon-tickyÂch pacientuÊ jsou deÏtia adolescenti. ZduÊraznÏujõÂ, zÏe poloha orgaÂnuÊ u mladyÂch lidõ je odlisÏnaÂ. Pokud se neberou v uÂvahu vsÏechny tyto odlisÏnosti, muÊzÏe dochaÂ-zet k chybne interpretaci zaÂveÏruÊ vyÂzkumuÊ, kdy vyÂ-sledky studiõ na dospeÏlyÂch budou pausÏalizovaÂny i na deÏtske pacienty. AutorÏicÏlaÂnku take poukazujõ na pro-bleÂm prÏeexponovaÂnõ deÏtõ s prÏõÂchodem CT do medicõÂny a zaÂrovenÏ se obaÂvajõÂ, zÏe pod reklamnõÂm tlakem zduÊraz-nÏujõÂcõÂm nõÂzke daÂvky u CBCT prÏõÂstrojuÊ klinicÏtõÂleÂkarÏipod-cenõ skutecÏne daÂvky u mladyÂch lidõ [8].

ProbleÂm odpoveÏdnosti

DalsÏõÂprobleÂm, ktery se v soucÏasne dobeÏ vynorÏuje, se tyÂka odpoveÏdnostiza hodnocenõ CBCT zobrazenõÂ. Pa-tologicke uÂtvary z cele maxillofaciaÂlnõ oblastiby meÏl optimaÂlneÏ hodnotit radiolog a zpraÂvu posõÂlat indikujõÂ-cõÂmu specialistovi (naprÏ. stomatologovicÏiortodonti-stovi). SkutecÏnost je ale takovaÂ, zÏe CBCT prÏõÂstroj muÊzÏe vlastnit jakyÂkoliv specialista vcÏetneÏ ortodontistuÊ a tak iinterpretace snõÂmkuÊ zuÊstaÂva na teÏchto leÂkarÏõÂch. Vzhle-dem k tomu, zÏe se cÏasto nejedna jen o zobrazenõ den-tice, je nutneÂ, aby stomatologove meÏlidostatecÏne veÏ-domostia zkusÏenosti v oblasti anatomie a patologie hlavy a krku. Farman upozornÏuje, zÏe pokud nebude hodnotit CBCT zkusÏeny leÂkarÏ, muÊzÏe dojõÂt nejen k chybne interpretaci s naÂslednou neadekvaÂtnõ leÂcÏbou, ale ik prÏehleÂdnutõ ruÊznyÂch patologickyÂch procesuÊ [9]. Organizace HPA (The Health Protection Agency ) ve Velke BritaÂnii doporucÏuje, aby CBCT hodnotil bud'do-statecÏneÏ zkusÏeny a prosÏkoleny stomatolog nebo aby poskytovatel CBCT vysÏetrÏenõ zameÏstnaÂval radiologa, ktery pro neÏj bude CBCT hodnotit [10]. Podle Melse-nove by 3D radiografie meÏla byÂt soucÏaÂstõ vzdeÏlaÂvacõÂho programu v ortodoncii [11]. K tomuto naÂzoru se prÏiklaÂnõ iScarfe [12]. V prÏõÂpadeÏ patologickyÂch naÂlezuÊ mimo den-tici by se meÏl ortodontista radit jesÏteÏ s radiologem [11, 13]. Scarfe upozornÏuje na to, zÏe nenõ neobvykleÂ, zÏe prÏõÂmo firmy, ktere distribuujõ CBCT prÏõÂstroje, porÏaÂdajõ vzdeÏlaÂvacõ kurzy (kde komercÏnõ zaÂjem prÏevlaÂda nad zdravotnickyÂm). To vedlo k plaÂnovaÂnõ vzdeÏlaÂvacõÂch kurzuÊ na firmaÂch nezaÂvislyÂmi organizacemi. AAOMR (American Academy of Oral and Maxillofacial Radio-logy) je neziskova organizace reprezentovana maxilofa-ciaÂlnõÂmi radiology v USA. Tato organizace prÏedpoklaÂdaÂ, zÏe vsÏeobecny nekomercÏnõ vzdeÏlaÂvacõ kurz ohledneÏ CBCT by mohl byÂt zahaÂjen uzÏ v roce 2011. V podobneÂm

- 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 radiolo-gist [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 re-sponsibility 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 Radiologi-cal 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 establis-hed 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 survi-vors 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 as-signed higher tissue weighted factors [14]. Thus, the risk of malign tumours incidence in the orofacial area due to radiographic examination of head and neck (in-cluding 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 conven-tional CT [14]. On the other hand, two-dimensional examination is static and limited [11]. Therefore, the choice of appropriate radiological examination requi-res a well-thought strategy aimed at the required diag-nostic 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 radia-tion 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 per-centage and risk for individual imaging techniques rozsahu se bude konat iv jinyÂch zemõÂch, naprÏ. ve VelkeÂ

BritaÂnii, NeÏmecku, RÏecku, cÏi DaÂnsku.

LegislativnõÂdodatek by meÏl rozdeÏli t CT prÏõÂstroje na 2 typy:

- s malyÂm FOV (field of view), ktery muÊzÏe obsluhovat istomatolog po absolvovaÂnõ neÏkolikadennõÂho kurzu

- s velkyÂm FOV , ktery bude dostupny pro stomato-logy azÏ po uÂspeÏsÏne interpretaci 50 prÏõÂpaduÊ za prÏõÂtomnostiorofaciaÂlnõÂho radiologa [12]

Zjistilo se, zÏe prÏipouzÏõÂvaÂnõ CBCT vysÏetrÏenõ se naÂ-hodneÏ diagnostikuje veÏtsÏõ mnozÏstvõ vedlejsÏõÂch patolo-gickyÂch naÂlezuÊ. Mezityto naÂlezy patrÏõ naprÏõÂklad naÂ-hodne objevenõ rozsÏteÏpu obratluÊ ( spina bifida ), cizõÂho teÏlesa v hornõÂch dyÂchacõÂch cestaÂch, condylus bifidus temporomandibulaÂrnõÂho kloubu [13]. Proto mõÂra zod-poveÏdnostiprÏihodnocenõ CBCT je vyÂznamnaÂ. Je nutno prohleÂdnout cely zobrazovany objem CBCT a nezameÏrÏovat se jen na oblast zaÂjmu. Vzhledem k ne-dostatecÏne legislativeÏ se muÊzÏe staÂt, zÏe budou stoma-tologove v budoucnosticÏelit zÏalobaÂm z chybne inter-pretace CBCT snõÂmkuÊ [11].

ZmeÏny vaÂhovyÂch faktoruÊ pro jednotlive orgaÂny MezinaÂrodnõ komise radiologicke ochrany ICRP (In-ternational Commission on Radiological Protection) v roce 2007 opeÏtovneÏ prÏehodnotila tkaÂnÏove vaÂhove faktory. Stimul k revizi hodnot tkaÂnÏovyÂch vaÂhovyÂch faktoruÊ vznikl na zaÂkladeÏ novyÂch informacõ o incidenci naÂdoruÊ. V roce 1990, kdy se urcÏovaly tkaÂnÏove vaÂhove faktory prÏed revizõ naposledy, nebyly tyto informace je-sÏteÏ dostupneÂ. V te dobeÏ se jako riziko vzniku malignity zohlednÏovala jen mortalita. V roce 2007 se do tohoto rizika prÏipocÏõÂtala icelkova zaÂteÏzÏ onemocneÏnõ malignõÂm naÂdorem ( morbidita ) tzn., zÏe se zohlednily i ty typy naÂdoruÊ, pro ktere je charakteristicke dlouhodobe prÏe-zÏitõÂ. VeÏtsÏina uÂdajuÊ pochaÂzõ z dlouhodobeÂho monitoro-vaÂnõ osob, ktere prÏezÏili vyÂbuch atomove bomby v Ja-ponsku. Na zaÂkladeÏ teÏchto zjisÏteÏnõ se usoudilo, zÏe ri-ziko vzniku malignõÂho tumoru slinnyÂch zÏlaÂz a mozku je vysÏsÏõ a byly jim prÏirÏazeny vysÏsÏõ tkaÂnÏove vaÂhove fak-tory [14]. Riziko vzniku malignity v orofaciaÂlnõ oblasti vyplyÂvajõÂcõ z radiografickyÂch vysÏetrÏenõ hlavy a krku (vcÏetneÏ CBCT a MSCT ) je tedy vysÏsÏõ nezÏ se drÏõÂve prÏed-poklaÂdalo [12]. Ludlow a kol. konstatuje, zÏe daÂvka prÏi zhotovenõ CBCT je sice vysÏsÏõ nezÏ u konvencÏnõÂch radio-logickyÂch vysÏetrÏenõÂ, ale na druhe straneÏ je mnohem ni-zÏsÏõ nezÏ u konvencÏnõ vyÂpocÏetnõ tomografie [14]. Naproti tomu dvojdimenzionaÂlnõ vysÏetrÏenõ je staticke a ome-zene [11]. MozÏnost volby ze sÏirokeÂho spektra pomoc-nyÂch zobrazovacõÂch metod vyzÏaduje promysÏlenou strategii vyÂbeÏru vhodneÂho zobrazovacõÂho vysÏetrÏenõ tak, aby byla dosazÏena pozÏadovana diagnosticka i n-formace s minimaÂlnõÂminaÂklady a rizikem pro pacienta [15].

and for a patient. In case of a low utilization percen-tage, there is a risk of wrong diagnosis, and conse-quently complications during the treatment.

There are hundreds of protocols for various exami-nations using imaging techniques. Often it is up to a ra-diologist or radiological assistant which technical pa-rameters are used. Ideally, the factors should be cho-sen to accomplish the examination with the lowest radiation load possible. However, most CT devices are preset by a manufacturer without regard to opti-mum 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 establis-hed 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 suffi-cient information. On the other hand, if it is necessary to make CBCT, for OPG and cephalogram the recon-structions 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 Mo-dality) (2009-2011). The project intends to obtain as much key information on CBCT as possible, and deter-mine at least temporary guidelines and recommenda-tions 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 resorp-tion, 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 cra-niofacial 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

DoporucÏenõ pro pouzÏõÂvaÂnõ CBCT ve stomatologii PrÏizhotovovaÂnõ CBCT, by se meÏla (v raÂmcisnõÂzÏenõ daÂvek) zvolit velikost zobrazovaneÂho pole ( FOV) tak, aby rozsahem odpovõÂdala oblastizaÂjmu. KraniofaciaÂlnõ CBCT je tedy vyhrazeno jen na ojedineÏle prÏõÂpady [9]. Rizika radiografickyÂch zobrazovacõÂch metod by roz-hodneÏ nemeÏla byÂt ignorovaÂna. ZaÂrovenÏ je nutne prÏi indikaci jednotlivyÂch zobrazovacõÂch metod zvaÂzÏit po-meÏr vyÂteÏzÏnosti/rizika pro danou zobrazovacõ metodu a pacienta. PrÏimale vyÂteÏzÏnostije mozÏnost vzniku diag-nostickeÂho omylu a s tõÂm naÂsledneÏ souvisejõÂcõ kompli-kace prÏileÂcÏbeÏ.

Jsou k dispozici stovky protokoluÊ pro ruÊzne vysÏe-trÏenõ pomocõ zobrazovacõÂch metod. CÏasto je rozhod-nutõ na radiologovi, nebo na radiologickeÂm asistentovi jake technicke parametry pouzÏije. IdeaÂlneÏ by meÏly byÂt tyto faktory vybraÂny tak, aby se dosaÂhlo cõÂle vysÏetrÏenõ prÏico mozÏna nejnizÏsÏõ daÂvce zaÂrÏenõÂ. Realita je vsÏak ob-vykle takovaÂ, zÏe veÏtsÏina CT prÏõÂstrojuÊ je nastavena od vyÂrobce bez uvaÂzÏenõ optimalizace daÂvky/kvality a je na samotneÂm radiologovi jestli zvaÂzÏõ faktory, jimizÏ muÊzÏe daÂvku snõÂzÏit [16, 14].

HPA (The Health Protection Agency) vznikla ve Velke BritaÂnii jako nezaÂvisla organizace, ktera byla se-stavena vlaÂdou v roce 2003, aby chraÂnila zdravõ verÏej-nosti. Vzhledem ke zvysÏujõÂcõ tendencik pouzÏõÂvaÂnõ CBCT ve Velke BritaÂnii se zacÏala zabyÂvat iotaÂzkou CBCT ve stomatologii. ZverÏejnila tabulku daÂvek CBCT a panoramatickeÂho snõÂmku. Po zhodnocenõ vyÂsledkuÊ prÏichaÂzõ k zaÂveÏru, zÏe CBCT by nemeÏlo nahradit pan-oramaticky a kefalometricky snõÂmek a jeho indikace by meÏla byÂt dobrÏe zvaÂzÏena. KvuÊlivysÏsÏõ radiacÏnõ zaÂteÏzÏi, nepovazÏuje HPA za vhodneÂ, aby bylo CBCT zhotovo-vaÂno vyÂhradneÏ za uÂcÏelem rekonstrukce OPG a kefalo-metrickeÂho snõÂmku, pokud jsou tato vysÏetrÏenõ sama o sobeÏ schopna poskytnout dostatecÏnou informaci. Na druhou stranu pokud by bylo nutne zhotovit CBCT, tak k zõÂskaÂnõ OPG a kefalometrickeÂho snõÂmku se vy-uzÏije rekonstrukcõ z CBCT [10].

Evropske spolecÏenstvõ pro atomovou energii (Euro-pean Atomic Energy Community,EAEC) si dalo za cõÂl vypracovat projekt SEDENTEXCT (Safety and Efficacy of a New and Emerging Dental X-ray Modality) (2009-2011). ZaÂmeÏrem projektu je zõÂskat co nejvõÂce klõÂcÏovyÂch informacõ o CBCT a urcÏit alesponÏ provizornõ smeÏrnice a doporucÏenõ pro pouzÏõÂvanõ CBCT ve stomatologii [17]. Po vypracovaÂnõ projektu SEDENTEXCT v roce 2011 uverÏejnilo EAEC doporucÏenõ pro pouzÏõÂvaÂnõ CBCT ve stomatologii. Hlavnõ zaÂsady jsou [18]:

- prÏihodnocenõÂretinovanyÂch zubuÊ a prÏilehlyÂch tkaÂnõÂ, vcÏetneÏ stanovenõÂ prÏõÂtomnostiresorpce okolnõÂch zubuÊ by se meÏlo preferovat CBCT vysÏetrÏenõÂ (vzhledem k jeho nizÏsÏõÂ daÂvce) prÏed MSCT (multislice CT). CBCT

- Craniofacial CBCT is preferred to MSCT in case of skeletal deformities, especially in patients with orthog-nathic surgery

- CBCT is not indicated for caries diagnostics - CBCT should not become a routine method for the assessment of periodontal bone condition, or for diag-nostics of periodontal pathological processes. In case where conventional radiography does not bring infor-mation 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-reso-lution 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 ana-tomy 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 le-sion which complicates endodontic treatment.

- Limited CBCT with high resolution may be indica-ted in root fractures in case conventional intraoral X-ray pictures did not provide sufficient information.

- CBCT may be indicated in cases when conventio-nal radiography proves close relation between third molar and mandibular canal, in order to detail its posi-tion prior to surgery

- CBCT may be indicated in case when conventional radiography did not bring sufficient information on im-pacted teeth

- In planning before implants insertion, CBCT is pre-ferred (due to lower radiation) to other techniques allo-wing 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 in-formation 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 orthogna-thic 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. se muÊzÏe indikovat, jen pokud se nezõÂska adekvaÂtnõÂ

in-formace z konvencÏnõ radiografie, ktera ma mnohem mensÏõ daÂvku zaÂrÏenõÂ. V prÏõÂpadeÏ rozhodnutõ o CBCT vy-sÏetrÏenõ by se meÏlo v raÂmciredukce daÂvky pouzÏõÂt co nejmensÏõ zobrazovane pole ( FOV), ktere zobrazõ jen oblast zaÂjmu. Pokud jsou k dispozici jen kraniofaciaÂlnõ CBCT (s velkyÂm FOV ), meÏlo by byÂt rozhodnutõ o prove-denõ vysÏetrÏenõ pecÏliveÏ zvaÂzÏeno.

- u rozsÏteÏpovyÂch pacientuÊ se dõÂky mensÏõÂdaÂvce daÂva prÏednost CBCT prÏed MSCT, prÏicÏemzÏ by FOV meÏlo od-povõÂdat velikosti oblasti ktera ma byÂt zobrazena

- CBCT nenõÂ normaÂlneÏ indikovaÂno v prÏõÂpadeÏ zavaÂ-deÏnõÂ docÏasnyÂch kotevnõÂch zarÏõÂzenõÂ

- CBCT s velkyÂm FOV by se nemeÏlo rutinneÏ pouzÏõÂvat v beÏzÏne ortodonticke diagnostice

- kraniofaciaÂlnõ CBCT je uprÏednostnÏovaÂno prÏed MSCT u skeletaÂlnõÂch deformit hlavneÏ pokud se jedna o ortodonticko-chirurgicky prÏõÂpad

- CBCT nenõÂ indikovaÂno k diagnostice kazuÊ

- CBCT by se nemeÏlo rutinneÏ pouzÏõÂvat k hodnocenõ stavu periodontaÂlnõ kosti ani k diagnostice parodontaÂl-nõÂch patologickyÂch procesuÊ. V prÏõÂpadech, kdy kon-vencÏnõ radiografie neposkytne potrÏebne informace ke zhodnocenõ furkacõ a jinyÂch parodontaÂlnõÂch defektuÊ, muÊzÏe se pouzÏõÂt CBCT s vysokyÂm rozlisÏenõÂm, ale malyÂm FOV. Naopak pokud CBCT vysÏetrÏenõ zobrazuje izuby, meÏla by se zkontrolovat iuÂrovenÏ prÏilehle kostia vyÂskyt prÏõÂpadnyÂch parodontaÂlnõÂch patologickyÂch procesuÊ. Li-mitovane CBCT s velkyÂm rozlisÏenõÂm se muÊzÏe pouzÏõÂt ke zhodnocenõ parodontaÂlnõÂch procesuÊ, pokud kon-vencÏnõ radiografie poskytla negativnõ vyÂsledek a je prÏõÂ-tomna klinicka symptomatologie

- CBCT se nema rutinneÏ pouzÏõÂvat k objasneÏnõÂanato-mie korÏenovyÂch kanaÂlkuÊ. Jen v omezenyÂch prÏõÂpadech se muÊzÏe pouzÏõÂt limitovane CBCT s vysokyÂm rozlisÏenõÂm a to naprÏ. u võÂcekorÏenoveÂho zubu, kde je nejasna ana-tomie korÏenovyÂch kanaÂlkuÊ, daÂle v prÏõÂpadech resorpce korÏene zaÂneÏtliveÂho charakteru, cÏivnitrÏnõÂho granulomu (kde trojdimenzionaÂlnõ zobrazenõ poskytne informaci o prognoÂze zubu), perforace, atypicke anatomie pulpy nebo v prÏõÂpadeÏ kombinovane pulpoparodontaÂlnõ leÂze, ktera komplikuje endodontickou leÂcÏbu

- limitovane CBCT s vysokyÂm rozlisÏenõÂm muÊzÏe byÂt indikovaÂno v prÏõÂpadech fraktur korÏene zubu, kde kon-vencÏnõ intraoraÂlnõ snõÂmky neposkytly dostatecÏnou in-formaci

- CBCT muÊzÏe byÂt indikovaÂno v prÏõÂpadech, kdy kon-vencÏnõÂ radiografie prokaÂzÏe teÏsnou souvislost mezi trÏe-tõÂm molaÂrem a mandibulaÂrnõÂm kanaÂlem, aby se de-tailneÏ objasnila jeho poloha prÏed chirurgickyÂm zaÂkro-kem

- pokud konvencÏnõ radiografie neposkytne dosta-tecÏne informace o retinovanyÂch zubech, muÊzÏe byÂt indi-kovaÂno CBCT

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, impac-ted 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 de-manding 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 sug-gests 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 inter-disciplinary cooperation in dentistry, and with the other specialists in medicine as well.

- prÏiplaÂnovaÂnõ prÏed zavedenõÂm implantaÂtuÊ se daÂva CBCT prÏednost (jako alternativeÏ s nizÏsÏõÂmi daÂvkami) prÏed jinyÂmimetodami, ktere umozÏnÏujõ zobrazenõ cÏelistõ v prÏõÂcÏnyÂch rÏezech (jako je naprÏ. MSCT)

- tam, kde je nutne zhodnocenõ meÏkkyÂch tkaÂnõ v raÂmci radiologickeÂho vysÏetrÏenõÂ, se daÂva prÏednost MSCT a magneticke resonanci(MR) prÏed CBCT

- u karcinomuÊ orofaciaÂlnõÂ oblasti, kde je podezrÏenõÂ na invazi do cÏelistnõÂch kostõÂ a MSCT spolu s MR nepo-skytly dostatecÏnou informaci o diagnoÂze a stadiu one-mocneÏnõÂ, se muÊzÏe zhotovit CBCT

- v prÏõÂpadech orofaciaÂlnõÂch traumat, kde je potrÏebne zobrazenõ v prÏõÂcÏnyÂch rÏezech a nenõ potrÏebne zobrazenõ meÏkkyÂch tkaÂnõÂ, se muÊzÏe kvuÊlinizÏsÏõ daÂvce daÂt prÏednost CBCT prÏed MSCT

- CBCT se muÊzÏe zhotovit v prÏõÂpadeÏ plaÂnovaÂnõ ortog-naÂtnõ operace, kde je potrÏebne trojdimenzionaÂlnõ zo-brazenõ skeletu

- pokud je pro zobrazenõÂ TMK indikovaÂno CT, je kvuÊlimensÏõÂ daÂvce zaÂrÏenõÂ uprÏednostnÏovaÂno CBCT prÏed MSCT

ZaÂveÏr

Obrovsky rozmach pouzÏõÂvaÂnõ CBCT v ortodoncii vedl Kokiche k zamysÏlenõÂ, zda prÏinese 3D zobrazenõ v ortodoncii skutecÏneÏ vzÏdy prospeÏch. Kokich jej pova-zÏuje za naÂpomocne u ektopickyÂch erupcõÂ, retinova-nyÂch zubuÊ a transpozicõÂ, kde umozÏnõ prostorove zo-brazenõ a zjednodusÏõ diagnoÂzu. Pochybuje vsÏak o tom, zÏe se pomocõ CBCT zlepsÏõ leÂcÏebny vyÂsledek u beÏzÏnyÂch anomaÂli õÂ. O cÏem nenõ pochyb je skutecÏnost, zÏe je toto vysÏetrÏenõ pro pacienta financÏneÏ naÂkladneÏjsÏõÂ. CBCT jisteÏ pomuÊzÏe pochopit zmeÏny po ortognaÂtnõÂch operacõÂch, protozÏe v teÏchto prÏõÂpadech skutecÏneÏ do-chaÂzõ k prostorovyÂm zmeÏnaÂm. Kokich ale varuje prÏed nadmeÏrnyÂm pouzÏõÂvaÂnõÂm (zneuzÏõÂvaÂnõÂm) CBCT praÂveÏ v teÏchto studiõÂch, kde pacienti absolvovali i 3 CBCT vy-sÏetrÏenõ beÏhem jednoho roku. Jako prvnõ doporucÏuje polozÏit si otaÂzku, zda zõÂskany prospeÏch ze zhotovenõ trojdimenzionaÂlnõÂho vysÏetrÏenõ skutecÏneÏ prÏevaÂzÏõ poten-cionaÂlnõ riziko pro pacienta. ZodpoveÏdnost je urcÏi teÏ na naÂs, na indikujõÂcõÂch leÂkarÏõÂch [6].

Z etickeÂho hlediska je leÂkarÏ povinen jednat v nejlep-sÏõÂm zaÂjmu pacienta i v dlouhodobeÂm horizontu. Je-li jizÏ CBCT vysÏetrÏenõÂ provedeno, meÏlo by byÂt sdõÂleno jak v raÂmci interdisciplinaÂrnõÂ spolupraÂce v raÂmcizubnõÂho leÂkarÏstvõÂ, tak i mezi specialisty jinyÂch oboruÊ.

13. rocÏnõÂk

JihocÏeskyÂch

ortodontickyÂch dnuÊ

¹PolyteÂmatikaª

ve dnech

26. a 27. 4. 2013

v CÏeskyÂch BudeÏjovicõÂch

v hotelu Maly pivovar.

Kontaktnõ adresa:MUDr. Milada HaÂlkovaÂ, VaÂclavska 282, 386 01 Strakonice, tel.: 603 925 227, e-mail: halek@iol.cz

Literatura/References

1. Scarfe, W. C.; Farman, A. G.: What is Cone-beam CT and how does it work? Dent. Clin. North Amer. 2008, 52, cÏ. 4, s. 707-730.

2. ZoÈller, J. E.; Neugebauer, J.: Cone-beam volumetric ima-ging in dental,oral and maxillofacial medicine. New Mal-den: Quintessence Publishing 2008.

3. Jacobson, A.; Jacobson, R. L.: Radiographic cephalome-try from basics to 3-D imaging. Illinois: Quintessence Publishing 2006.

4. Farman, A. G.; Scarfe, W. C.: The basics of maxillofacial Cone Beam Computed Tomography. Seminars in Ortho-dontics. 2009, 15, cÏ. 1, s. 2-13.

5. Zinman, E. J.; White, S. C.; Tetradis, S.: Legal considera-tions in the use of cone beam computer tomography ima-ging. J. Calif. Dent. Assoc. 2010, 38, s. 49-56. [Cit. in Scarfe, W. C.: ªAll that glitters is not goldª: standards for cone-beam computerized tomographic imaging. Oral Surg. Oral Med. Oral Pathol. Oral Radiol. Endod. 2011, 111, cÏ. 4, s. 402-408.]

6. Kokich, V. G.: Cone-beam computed tomography: have we identified the orthodontic benefits? Amer. J. Ortho-dont. dentofacial Orthop. 2010, 137, cÏ. 4, s. 16.

7. Dostupne z URL http://www.nytimes.com/2010/11/23/ us/23scan.html?pagewanted=all.

8. Hujoel, P.; Hollender, L.; Bollen, A. M.; Young, J. D.; McGee, M.; Grosso, A.: Head-and-neck organ doses from an episode of orthodontic care. Amer. J. Orthodont. den-tofacial Orthop. 2008, 133, cÏ. 2, s. 210-217.

9. Farman, A. G.: ALARA still applies. Oral Surg. Oral Med. Oral Pathol. Oral Radiol. Endod. 2005, 100, cÏ. 4, s. 395-397.

10. Dostupne z URL http://www.hpa.org.uk/webc/HPA-webFile/HPAweb_C/1246433630996

11. Cattaneo, P. M.; Melsen, B.: The use of cone-beam com-puted tomography in an orthodontic department in bet-ween research and daily clinic. World. J. Orthod. 2008, 9, cÏ. 3, s. 269-282.

12. Scarfe, W. C.: ¹All that glitters is not goldª: standards for cone-beam computerized tomographic imaging. Oral Surg. Oral Med. Oral Pathol. Oral Radiol. Endod. 2011, 111, cÏ. 4, s. 402-408.

13. Rogers, S. A.; Drage, N.; Durning P.: Incidental findings arising with cone beam computed tomography imaging of the orthodontic patient. Angle Orthodont. 2011, 81, cÏ. 2, s. 350-355.

14. Ludlow, J.B.; Ivanovic, M.: Comparative dosimetry of dental CBCT devices and 64-slice CT for oral and maxil-lofacial radiology. Oral Surg. Oral Med. Oral Pathol. Oral Radiol. Endod. 2008, 106, cÏ. 1, s. 106-114.

15. McNeill, CH.; Hatcher, D. C.: Science and practice of occlusion. Illinois: Quintessence Publishing 1997. 16. VaÂlek, V.: Modernõ diagnosticke metody. II.dõÂl. VyÂpocÏetnõÂ

tomografie, Brno : Institut pro dalsÏõÂ vzdeÏlaÂvaÂnõÂ pracov-nõÂkuÊ ve zdravotnictvõÂ v BrneÏ, 1998.

17. Turpin, D. L.: Clinical guidelines and the use of cone-beam computed tomography. Amer. J. Orthodont. den-tofacial Orthop. 2010, 138, cÏ. 1, s. 1-2.

18. Dostupne z URL http://www.sedentexct.eu/files/guide-lines_final.pdf.

MUDr. Daniela HlousÏkova Stomatologicka klinika 1.LF UK KaterÏinska 32, 120 00 Praha 2

ROD OSTRAVA

PrÏehled chystanyÂch domaÂcõÂch akcõÂ 2013:

12. 1. 2013 Mgr. JirÏõÂ BeÏl

Praha ¹DigitaÂlnõ fotografie v ortodonticke praxiª

± prakticky kurz

PrÏehled chystanyÂch zahranicÏnõÂch akcõÂ 2013:

26.±30. 6. 2013 89th Congress of the European Association of Orthodontics

Reykjavik, Island

* * *

Informace: ROD Ostrava ± BeÏlova Olga, MojmõÂrovcuÊ 799/45, 709 00 Ostrava-Mar. Hory Tel.: 777 727 152, 800 100 793, e-mail: obchod@rod-ostrava.cz