Cyan Magenta Yellow Black
rocÏnõÂk 21
cÏ. 4. 2012
Odborna praÂce
ORTODONCIE
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 kdyzÏ bylo CBCT (Cone Beam computerized tomography) prÏedstaveno jizÏ prÏed cÏtvrt stoletõÂm, teprve v poslednõÂ
dekaÂdeÏ se podarÏilo vyvinout systeÂm prÏimeÏrÏenyÂch rozmeÏruÊ a zaÂrovenÏ cenoveÏ dostupnyÂ, ktery je pouzÏitelny i v ortodontickyÂch praxõÂch. OrtodontistuÊm poskytuje pro diagnoÂzu a stanovenõ leÂcÏebneÂho plaÂnu nejen zobrazenõ dvojdimenzionaÂlnõ (2D), ale zejmeÂna zobrazenõ trojdimenzionaÂlnõ (3D) [1].
TeÏchto mozÏnostõ se v ortodoncii s vyÂhodou vyuzÏÂõva k detailnõÂmu zjisÏteÏnõ polohy retinovanyÂch zubuÊ, k objasneÏnõÂ
mozÏnyÂch resorpcõÂ korÏenuÊ prÏilehlyÂch zubuÊ, u asymetriõÂ oblicÏejoveÂho skeletu, prÏÂõpadneÏ u parodontologickyÂch
pacientuÊ s insuficiencõÂ kosti [2]. PrÏÂõchod CBCT muÊzÏe prÏislõÂbit i dokonalejsÏÂõ 3D kefalometrickou analyÂzu [3]. KromeÏ
toho CBCT vysÏetrÏenõÂ nachaÂzõÂ svoje mõÂsto i v implantologii a v maxilofaciaÂlnõÂ chirurgii [2]. Nespornou vyÂhodou
CBCT v porovnaÂnõÂ s FBCT (Fan Beam computerized tomography) je, zÏe je prÏesneÏjsÏÂõ, skenovacõÂ cÏas je kratsÏÂõ,
je znacÏneÏ levneÏjsÏÂõ a zejmeÂna ma mnohem mensÏÂõ 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 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. 192-198).
Realita a CBCT
CBCT je vsÏeobecneÏ povazÏovaÂno za ªzlaty standardª pro diagnostiku v maxilofaciaÂlnõ oblasti [5]. Ale
zacÏõÂnajõ prÏevlaÂdat i opacÏne naÂzory [6]. V roce 2010 vysÏel v americkyÂch novinaÂch The New York Times cÏlaÂnek, na jehozÏ zaÂkladeÏ se dostala do poveÏdomõ spolecÏnosti skutecÏnost, zÏe pouzÏitõ CBCT v ortodoncii je spojeno s radiacÏnõ zaÂteÏzÏõÂ, ktera je pod tlakem marketingu
prodejcuÊ rtg prÏõÂstrojuÊ podcenÏovaÂna [7]. Farman, prezident AAOMR (American Academy of Oral and Maxillofacial Radiology) poukazuje na nezbytnost ochrany
192
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
www.orthodont-cz.cz e-mail: [email protected]
Cyan Magenta Yellow -
Cyan Magenta Yellow Black
ORTODONCIE
Odborna praÂce
prÏed radiacÏnõÂ zaÂteÏzÏõÂ spojenou s pouzÏõÂvaÂnõÂm CBCT a to
zejmeÂna u deÏtõÂ, ktere jsou radiosenzitivneÏjsÏõ [7]. Obavy
vidõÂ jako opodstatneÏneÂ, protozÏe s prÏõÂchodem CT prÏõÂstrojuÊ do pediatrie dosÏlo v minulosti k prÏeexponovaÂnõÂ
deÏtõÂ. A podobny trend nastaÂva i v soucÏasne dobeÏ [8].
Za povsÏimnutõ stojõ i cÏlaÂnek Hujoela a kol., kterÏõ poukazujõ na to, zÏe velke mnozÏstvõ studiõ se zabyÂva orgaÂnovyÂmi daÂvkami u dospeÏlyÂch, zatõÂmco veÏtsÏina ortodontickyÂch pacientuÊ jsou deÏti a adolescenti. ZduÊraznÏujõÂ,
zÏe poloha orgaÂnuÊ u mladyÂch lidõÂ je odlisÏnaÂ. Pokud se
neberou v uÂvahu vsÏechny tyto odlisÏnosti, muÊzÏe dochaÂzet k chybne interpretaci zaÂveÏruÊ vyÂzkumuÊ, kdy vyÂsledky studiõ na dospeÏlyÂch budou pausÏalizovaÂny i na
deÏtske pacienty. AutorÏi cÏlaÂnku take poukazujõ na probleÂm prÏeexponovaÂnõ deÏtõ s prÏõÂchodem CT do medicõÂny
a zaÂrovenÏ se obaÂvajõÂ, zÏe pod reklamnõÂm tlakem zduÊraznÏujõÂcõÂm nõÂzke daÂvky u CBCT prÏõÂstrojuÊ klinicÏtõ leÂkarÏi podcenõ skutecÏne daÂvky u mladyÂch lidõ [8].
ProbleÂm odpoveÏdnosti
DalsÏõ probleÂm, ktery se v soucÏasne dobeÏ vynorÏuje, se
tyÂka odpoveÏdnosti za hodnocenõ CBCT zobrazenõÂ. Patologicke uÂtvary z cele maxillofaciaÂlnõ oblasti by meÏl
optimaÂlneÏ hodnotit radiolog a zpraÂvu posõÂlat indikujõÂcõÂmu specialistovi (naprÏ. stomatologovi cÏi ortodontistovi ). SkutecÏnost je ale takovaÂ, zÏe CBCT prÏõÂstroj muÊzÏe
vlastnit jakyÂkoliv specialista vcÏetneÏ ortodontistuÊ a tak
i interpretace snõÂmkuÊ zuÊstaÂva na teÏchto leÂkarÏõÂch. Vzhledem k tomu, zÏe se cÏasto nejedna jen o zobrazenõ dentice, je nutneÂ, aby stomatologove meÏli dostatecÏne veÏdomosti a 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 i k prÏehleÂdnutõÂ ruÊznyÂch patologickyÂch procesuÊ [9].
Organizace HPA (The Health Protection Agency ) ve
Velke BritaÂnii doporucÏuje, aby CBCT hodnotil bud' dostatecÏneÏ zkusÏeny a prosÏkoleny stomatolog nebo aby
poskytovatel CBCT vysÏetrÏenõÂ zameÏstnaÂval radiologa,
ktery pro neÏj bude CBCT hodnotit [10]. Podle Melsenove by 3D radiografie meÏla byÂt soucÏaÂstõ vzdeÏlaÂvacõÂho
programu v ortodoncii [11]. K tomuto naÂzoru se prÏiklaÂnõÂ
i Scarfe [12]. V prÏõÂpadeÏ patologickyÂch naÂlezuÊ mimo dentici by se meÏl ortodontista radit jesÏteÏ s radiologem [11,
13]. Scarfe upozornÏuje na to, zÏe nenõÂ neobvykleÂ, zÏe
prÏõÂmo firmy, ktere distribuujõ CBCT prÏõÂstroje, porÏaÂdajõÂ
vzdeÏlaÂvacõ kurzy (kde komercÏnõ zaÂjem prÏevlaÂda nad
zdravotnickyÂm). To vedlo k plaÂnovaÂnõÂ vzdeÏlaÂvacõÂch
kurzuÊ na firmaÂch nezaÂvislyÂmi organizacemi. AAOMR
(American Academy of Oral and Maxillofacial Radiology) je neziskova organizace reprezentovana maxilofaciaÂlnõÂmi radiology v USA. Tato organizace prÏedpoklaÂdaÂ,
zÏe vsÏeobecny nekomercÏnõ vzdeÏlaÂvacõ kurz ohledneÏ
CBCT by mohl byÂt zahaÂjen uzÏ v roce 2011. V podobneÂm
www.orthodont-cz.cz e-mail: [email protected]
Cyan Magenta Yellow -
rocÏnõÂk 21
cÏ. 4. 2012
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 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 operated by a dentist after he attended a short course.
193
Cyan Magenta Yellow Black
rocÏnõÂk 21
cÏ. 4. 2012
Odborna praÂce
rozsahu se bude konat i v jinyÂch zemõÂch, naprÏ. ve VelkeÂ
BritaÂnii, NeÏmecku, RÏecku, cÏi DaÂnsku.
LegislativnõÂ dodatek by meÏl rozdeÏlit CT prÏõÂstroje na 2
typy:
- s malyÂm FOV (field of view), ktery muÊzÏe obsluhovat
i stomatolog po absolvovaÂnõÂ neÏkolikadennõÂho kurzu
- s velkyÂm FOV , ktery bude dostupny pro stomatology azÏ po uÂspeÏsÏne interpretaci 50 prÏõÂpaduÊ za
prÏõÂtomnosti orofaciaÂlnõÂho radiologa [12]
Zjistilo se, zÏe prÏi pouzÏõÂvaÂnõ CBCT vysÏetrÏenõ se naÂhodneÏ diagnostikuje veÏtsÏõ mnozÏstvõ vedlejsÏõÂch patologickyÂch naÂlezuÊ. Mezi tyto naÂlezy patrÏõ naprÏõÂklad naÂhodne objevenõ rozsÏteÏpu obratluÊ ( spina bifida ), cizõÂho
teÏlesa v hornõÂch dyÂchacõÂch cestaÂch, condylus bifidus
temporomandibulaÂrnõÂho kloubu [13]. Proto mõÂra zodpoveÏdnosti prÏi hodnocenõÂ CBCT je vyÂznamnaÂ. Je
nutno prohleÂdnout cely zobrazovany objem CBCT
a nezameÏrÏovat se jen na oblast zaÂjmu. Vzhledem k nedostatecÏne legislativeÏ se muÊzÏe staÂt, zÏe budou stomatologove v budoucnosti cÏelit zÏalobaÂm z chybne interpretace CBCT snõÂmkuÊ [11].
ZmeÏny vaÂhovyÂch faktoruÊ pro jednotlive orgaÂny
MezinaÂrodnõ komise radiologicke ochrany ICRP (International Commission on Radiological Protection)
v roce 2007 opeÏtovneÏ prÏehodnotila tkaÂnÏove vaÂhoveÂ
faktory. Stimul k revizi hodnot tkaÂnÏovyÂch vaÂhovyÂch
faktoruÊ vznikl na zaÂkladeÏ novyÂch informacõÂ o incidenci
naÂdoruÊ. V roce 1990, kdy se urcÏovaly tkaÂnÏove vaÂhoveÂ
faktory prÏed revizõ naposledy, nebyly tyto informace jesÏteÏ dostupneÂ. V te dobeÏ se jako riziko vzniku malignity
zohlednÏovala jen mortalita. V roce 2007 se do tohoto
rizika prÏipocÏõÂtala i celkova zaÂteÏzÏ onemocneÏnõ malignõÂm
naÂdorem ( morbidita ) tzn., zÏe se zohlednily i ty typy
naÂdoruÊ, pro ktere je charakteristicke dlouhodobe prÏezÏitõÂ. VeÏtsÏina uÂdajuÊ pochaÂzõ z dlouhodobeÂho monitorovaÂnõ osob, ktere prÏezÏili vyÂbuch atomove bomby v Japonsku. Na zaÂkladeÏ teÏchto zjisÏteÏnõ se usoudilo, zÏe riziko vzniku malignõÂho tumoru slinnyÂch zÏlaÂz a mozku
je vysÏsÏõ a byly jim prÏirÏazeny vysÏsÏõ tkaÂnÏove vaÂhove faktory [14]. Riziko vzniku malignity v orofaciaÂlnõ oblasti
vyplyÂvajõÂcõÂ z radiografickyÂch vysÏetrÏenõÂ hlavy a krku
(vcÏetneÏ CBCT a MSCT ) je tedy vysÏsÏõÂ nezÏ se drÏõÂve prÏedpoklaÂdalo [12]. Ludlow a kol. konstatuje, zÏe daÂvka prÏi
zhotovenõ CBCT je sice vysÏsÏõ nezÏ u konvencÏnõÂch radiologickyÂch vysÏetrÏenõÂ, ale na druhe straneÏ je mnohem nizÏsÏõ nezÏ u konvencÏnõ vyÂpocÏetnõ tomografie [14]. Naproti
tomu dvojdimenzionaÂlnõ vysÏetrÏenõ je staticke a omezene [11]. MozÏnost volby ze sÏirokeÂho spektra pomocnyÂch zobrazovacõÂch metod vyzÏaduje promysÏlenou
strategii vyÂbeÏru vhodneÂho zobrazovacõÂho vysÏetrÏenõÂ
tak, aby byla dosazÏena pozÏadovana diagnosticka informace s minimaÂlnõÂmi naÂklady a rizikem pro pacienta
[15].
194
ORTODONCIE
- 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
www.orthodont-cz.cz e-mail: [email protected]
Cyan Magenta Yellow -
Cyan Magenta Yellow Black
ORTODONCIE
Odborna praÂce
DoporucÏenõÂ pro pouzÏõÂvaÂnõÂ CBCT ve stomatologii
PrÏi zhotovovaÂnõÂ CBCT, by se meÏla (v raÂmci snõÂzÏenõÂ
daÂvek) zvolit velikost zobrazovaneÂho pole ( FOV) tak,
aby rozsahem odpovõÂdala oblasti zaÂjmu. KraniofaciaÂlnõÂ
CBCT je tedy vyhrazeno jen na ojedineÏle prÏõÂpady [9].
Rizika radiografickyÂch zobrazovacõÂch metod by rozhodneÏ nemeÏla byÂt ignorovaÂna. ZaÂrovenÏ je nutne prÏi
indikaci jednotlivyÂch zobrazovacõÂch metod zvaÂzÏit pomeÏr vyÂteÏzÏnosti/rizika pro danou zobrazovacõÂ metodu
a pacienta. PrÏi male vyÂteÏzÏnosti je mozÏnost vzniku diagnostickeÂho omylu a s tõÂm naÂsledneÏ souvisejõÂcõ komplikace prÏi leÂcÏbeÏ.
Jsou k dispozici stovky protokoluÊ pro ruÊzne vysÏetrÏenõ pomocõ zobrazovacõÂch metod. CÏasto je rozhodnutõ na radiologovi, nebo na radiologickeÂm asistentovi
jake technicke parametry pouzÏije. IdeaÂlneÏ by meÏly byÂt
tyto faktory vybraÂny tak, aby se dosaÂhlo cõÂle vysÏetrÏenõÂ
prÏi co mozÏna nejnizÏsÏõ daÂvce zaÂrÏenõÂ. Realita je vsÏak obvykle takovaÂ, zÏe veÏtsÏina CT prÏõÂstrojuÊ je nastavena od
vyÂrobce bez uvaÂzÏenõÂ optimalizace daÂvky/kvality a je
na samotneÂm radiologovi jestli zvaÂzÏõÂ faktory, jimizÏ
muÊzÏe daÂvku snõÂzÏit [16, 14].
HPA (The Health Protection Agency) vznikla ve
Velke BritaÂnii jako nezaÂvisla organizace, ktera byla sestavena vlaÂdou v roce 2003, aby chraÂnila zdravõ verÏejnosti. Vzhledem ke zvysÏujõÂcõ tendenci k pouzÏõÂvaÂnõÂ
CBCT ve Velke BritaÂnii se zacÏala zabyÂvat i otaÂzkou
CBCT ve stomatologii. ZverÏejnila tabulku daÂvek CBCT
a panoramatickeÂho snõÂmku. Po zhodnocenõÂ vyÂsledkuÊ
prÏichaÂzõ k zaÂveÏru, zÏe CBCT by nemeÏlo nahradit panoramaticky a kefalometricky snõÂmek a jeho indikace
by meÏla byÂt dobrÏe zvaÂzÏena. KvuÊli vysÏsÏõÂ radiacÏnõÂ zaÂteÏzÏi,
nepovazÏuje HPA za vhodneÂ, aby bylo CBCT zhotovovaÂno vyÂhradneÏ za uÂcÏelem rekonstrukce OPG a kefalometrickeÂho snõÂmku, pokud jsou tato vysÏetrÏenõÂ sama
o sobeÏ schopna poskytnout dostatecÏnou informaci.
Na druhou stranu pokud by bylo nutne zhotovit CBCT,
tak k zõÂskaÂnõÂ OPG a kefalometrickeÂho snõÂmku se vyuzÏije rekonstrukcõÂ z CBCT [10].
Evropske spolecÏenstvõ 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) (20092011). ZaÂmeÏrem projektu je zõÂskat co nejvõÂce klõÂcÏovyÂch
informacõÂ o CBCT a urcÏit alesponÏ provizornõÂ smeÏrnice
a doporucÏenõÂ pro pouzÏõÂvanõÂ CBCT ve stomatologii [17].
Po vypracovaÂnõÂ projektu SEDENTEXCT v roce
2011 uverÏejnilo EAEC doporucÏenõÂ pro pouzÏõÂvaÂnõÂ
CBCT ve stomatologii. HlavnõÂ zaÂsady jsou [18]:
- prÏi hodnocenõÂ retinovanyÂch zubuÊ a prÏilehlyÂch tkaÂnõÂ,
vcÏetneÏ stanovenõÂ prÏõÂtomnosti resorpce okolnõÂch zubuÊ
by se meÏlo preferovat CBCT vysÏetrÏenõÂ (vzhledem
k jeho nizÏsÏõÂ daÂvce) prÏed MSCT (multislice CT). CBCT
www.orthodont-cz.cz e-mail: [email protected]
Cyan Magenta Yellow -
rocÏnõÂk 21
cÏ. 4. 2012
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) (2009-2011). 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
Cyan Magenta Yellow Black
rocÏnõÂk 21
cÏ. 4. 2012
Odborna praÂce
se muÊzÏe indikovat, jen pokud se nezõÂska adekvaÂtnõ informace z konvencÏnõ radiografie, ktera ma mnohem
mensÏõÂ daÂvku zaÂrÏenõÂ. V prÏõÂpadeÏ rozhodnutõÂ o CBCT vysÏetrÏenõÂ by se meÏlo v raÂmci redukce daÂvky pouzÏõÂt co
nejmensÏõ zobrazovane pole ( FOV), ktere zobrazõ jen
oblast zaÂjmu. Pokud jsou k dispozici jen kraniofaciaÂlnõÂ
CBCT (s velkyÂm FOV ), meÏlo by byÂt rozhodnutõÂ o provedenõÂ vysÏetrÏenõÂ pecÏliveÏ zvaÂzÏeno.
- u rozsÏteÏpovyÂch pacientuÊ se dõÂky mensÏõÂ daÂvce daÂvaÂ
prÏednost CBCT prÏed MSCT, prÏicÏemzÏ by FOV meÏlo odpovõÂdat velikosti oblasti ktera ma byÂt zobrazena
- CBCT nenõÂ normaÂlneÏ indikovaÂno v prÏõÂpadeÏ zavaÂdeÏnõÂ docÏasnyÂch kotevnõÂch zarÏõÂzenõÂ
- CBCT s velkyÂm FOV by se nemeÏlo rutinneÏ pouzÏõÂvat
v beÏzÏne ortodonticke diagnostice
- kraniofaciaÂlnõÂ CBCT je uprÏednostnÏovaÂno prÏed
MSCT u skeletaÂlnõÂch deformit hlavneÏ pokud se jednaÂ
o ortodonticko-chirurgicky prÏõÂpad
- CBCT nenõÂ indikovaÂno k diagnostice kazuÊ
- CBCT by se nemeÏlo rutinneÏ pouzÏõÂvat k hodnocenõÂ
stavu periodontaÂlnõ kosti ani k diagnostice parodontaÂlnõÂch patologickyÂch procesuÊ. V prÏõÂpadech, kdy konvencÏnõ radiografie neposkytne potrÏebne informace ke
zhodnocenõÂ furkacõÂ a jinyÂch parodontaÂlnõÂch defektuÊ,
muÊzÏe se pouzÏõÂt CBCT s vysokyÂm rozlisÏenõÂm, ale malyÂm
FOV. Naopak pokud CBCT vysÏetrÏenõÂ zobrazuje i zuby,
meÏla by se zkontrolovat i uÂrovenÏ prÏilehle kosti a vyÂskyt
prÏõÂpadnyÂch parodontaÂlnõÂch patologickyÂch procesuÊ. Limitovane CBCT s velkyÂm rozlisÏenõÂm se muÊzÏe pouzÏõÂt ke
zhodnocenõ parodontaÂlnõÂch procesuÊ, pokud konvencÏnõ radiografie poskytla negativnõ vyÂsledek a je prÏõÂtomna klinicka symptomatologie
- CBCT se nema rutinneÏ pouzÏõÂvat k objasneÏnõ anatomie korÏenovyÂch kanaÂlkuÊ. Jen v omezenyÂch prÏõÂpadech
se muÊzÏe pouzÏõÂt limitovane CBCT s vysokyÂm rozlisÏenõÂm
a to naprÏ. u võÂcekorÏenoveÂho zubu, kde je nejasna anatomie korÏenovyÂch kanaÂlkuÊ, daÂle v prÏõÂpadech resorpce
korÏene zaÂneÏtliveÂho charakteru, cÏi vnitrÏnõÂho granulomu
(kde trojdimenzionaÂlnõÂ zobrazenõÂ 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 konvencÏnõÂ intraoraÂlnõÂ snõÂmky neposkytly dostatecÏnou informaci
- CBCT muÊzÏe byÂt indikovaÂno v prÏõÂpadech, kdy konvencÏnõÂ radiografie prokaÂzÏe teÏsnou souvislost mezi trÏetõÂm molaÂrem a mandibulaÂrnõÂm kanaÂlem, aby se detailneÏ objasnila jeho poloha prÏed chirurgickyÂm zaÂkrokem
- pokud konvencÏnõ radiografie neposkytne dostatecÏne informace o retinovanyÂch zubech, muÊzÏe byÂt indikovaÂno CBCT
196
ORTODONCIE
- 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 Xray 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.
www.orthodont-cz.cz e-mail: [email protected]
Cyan Magenta Yellow -
Cyan Magenta Yellow Black
ORTODONCIE
- prÏi plaÂnovaÂnõÂ prÏed zavedenõÂm implantaÂtuÊ se daÂvaÂ
CBCT prÏednost (jako alternativeÏ s nizÏsÏõÂmi daÂvkami)
prÏed jinyÂmi metodami, ktere umozÏnÏujõ zobrazenõ cÏelistõÂ
v prÏõÂcÏnyÂch rÏezech (jako je naprÏ. MSCT)
- tam, kde je nutne zhodnocenõ meÏkkyÂch tkaÂnõÂ
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 neposkytly dostatecÏnou informaci o diagnoÂze a stadiu onemocneÏnõÂ, se muÊzÏe zhotovit CBCT
- v prÏõÂpadech orofaciaÂlnõÂch traumat, kde je potrÏebneÂ
zobrazenõ v prÏõÂcÏnyÂch rÏezech a nenõ potrÏebne zobrazenõÂ
meÏkkyÂch tkaÂnõÂ, se muÊzÏe kvuÊli nizÏsÏõÂ daÂvce daÂt prÏednost
CBCT prÏed MSCT
- CBCT se muÊzÏe zhotovit v prÏõÂpadeÏ plaÂnovaÂnõ ortognaÂtnõ operace, kde je potrÏebne trojdimenzionaÂlnõ zobrazenõ skeletu
- pokud je pro zobrazenõÂ TMK indikovaÂno CT, je
kvuÊli mensÏõÂ daÂvce zaÂrÏenõÂ uprÏednostnÏovaÂno CBCT prÏed
MSCT
ZaÂveÏr
Obrovsky rozmach pouzÏõÂvaÂnõ CBCT v ortodoncii
vedl Kokiche k zamysÏlenõÂ, zda prÏinese 3D zobrazenõÂ
v ortodoncii skutecÏneÏ vzÏdy prospeÏch. Kokich jej povazÏuje za naÂpomocne u ektopickyÂch erupcõÂ, retinovanyÂch zubuÊ a transpozicõÂ, kde umozÏnõ prostorove zobrazenõ a zjednodusÏõ diagnoÂzu. Pochybuje vsÏak
o tom, zÏe se pomocõ CBCT zlepsÏõ leÂcÏebny vyÂsledek
u beÏzÏnyÂch anomaÂliõÂ. O cÏem nenõÂ pochyb je skutecÏnost,
zÏe je toto vysÏetrÏenõÂ pro pacienta financÏneÏ naÂkladneÏjsÏõÂ.
CBCT jisteÏ pomuÊzÏe pochopit zmeÏny po ortognaÂtnõÂch
operacõÂch, protozÏe v teÏchto prÏõÂpadech skutecÏneÏ dochaÂzõÂ k prostorovyÂm zmeÏnaÂm. Kokich ale varuje prÏed
nadmeÏrnyÂm pouzÏõÂvaÂnõÂm (zneuzÏõÂvaÂnõÂm) CBCT praÂveÏ
v teÏchto studiõÂch, kde pacienti absolvovali i 3 CBCT vysÏetrÏenõÂ beÏhem jednoho roku. Jako prvnõÂ doporucÏuje
polozÏit si otaÂzku, zda zõÂskany prospeÏch ze zhotovenõÂ
trojdimenzionaÂlnõÂho vysÏetrÏenõÂ skutecÏneÏ prÏevaÂzÏõÂ potencionaÂlnõÂ riziko pro pacienta. ZodpoveÏdnost je urcÏiteÏ na
naÂs, na indikujõÂcõÂch leÂkarÏõÂch [6].
Z etickeÂho hlediska je leÂkarÏ povinen jednat v nejlepsÏõÂm zaÂjmu pacienta i v dlouhodobeÂm horizontu. Je-li jizÏ
CBCT vysÏetrÏenõÂ provedeno, meÏlo by byÂt sdõÂleno jak
v raÂmci interdisciplinaÂrnõÂ spolupraÂce v raÂmci zubnõÂho
leÂkarÏstvõÂ, tak i mezi specialisty jinyÂch oboruÊ.
www.orthodont-cz.cz e-mail: [email protected]
Cyan Magenta Yellow -
rocÏnõÂk 21
cÏ. 4. 2012
Odborna praÂce
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.
Ï nõÂk
13. roc
Ï eskyÂch
Jihoc
ortodontickyÂch dnuÊ
¹PolyteÂmatikaª
ve dnech 26. a 27. 4. 2013
Ï eskyÂch BudeÏjovicõÂch
vC
v hotelu Maly pivovar.
KontaktnõÂ adresa: MUDr. Milada HaÂlkovaÂ,
VaÂclavska 282, 386 01 Strakonice,
tel.: 603 925 227, e-mail: [email protected]
197
Cyan Magenta Yellow Black
rocÏnõÂk 21
cÏ. 4. 2012
Odborna praÂce
ORTODONCIE
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 imaging in dental,oral and maxillofacial medicine. New Malden: Quintessence Publishing 2008.
3. Jacobson, A.; Jacobson, R. L.: Radiographic cephalometry 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 Orthodontics. 2009, 15, cÏ. 1, s. 2-13.
5. Zinman, E. J.; White, S. C.; Tetradis, S.: Legal considerations in the use of cone beam computer tomography imaging. 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. Orthodont. 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. dentofacial 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/HPAwebFile/HPAweb_C/1246433630996
11. Cattaneo, P. M.; Melsen, B.: The use of cone-beam computed tomography in an orthodontic department in between 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 maxillofacial 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 pracovnõÂkuÊ ve zdravotnictvõÂ v BrneÏ, 1998.
17. Turpin, D. L.: Clinical guidelines and the use of conebeam computed tomography. Amer. J. Orthodont. dentofacial Orthop. 2010, 138, cÏ. 1, s. 1-2.
18. Dostupne z URL http://www.sedentexct.eu/files/guidelines_final.pdf.
MUDr. Daniela HlousÏkovaÂ
Stomatologicka klinika 1.LF UK
KaterÏinska 32, 120 00 Praha 2
ROD OSTRAVA
PrÏehled chystanyÂch domaÂcõÂch akcõÂ 2013:
12. 1. 2013
Praha
Mgr. JirÏõÂ BeÏl
¹DigitaÂlnõ fotografie v ortodonticke praxiª
± prakticky kurz
PrÏehled chystanyÂch zahranicÏnõÂch akcõÂ 2013:
26.±30. 6. 2013
Reykjavik, Island
89th Congress of the European Association of Orthodontics
*
*
*
Informace: ROD Ostrava ± BeÏlova Olga, MojmõÂrovcuÊ 799/45, 709 00 Ostrava-Mar. Hory
Tel.: 777 727 152, 800 100 793, e-mail: [email protected]
198
www.orthodont-cz.cz e-mail: [email protected]
Cyan Magenta Yellow -
Download

Indikace snı¬mku Cone Beam CT. Souborny¬ refera¬ t. Indications