fotografija u stom

8/13/2019 Fotografija u Stom

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Serbian Dental J, 2006, 53 253

KRATAK SADRAJ Fotografija predstavlja dragocenu pomo u svim

oblastima medicine i stomatologije. Primena fotografije u stomatologiji je danas sastavni deo brojnih dijagnosti kihi terapijskih procedura i esto zna ajan dokument o tokui ishodu sprovedene terapije. Za intraoralne i ekstraoral-ne fotografije koriste se razli ite vrste aparata. Aparatikoji koriste film (Single Lens Reflex) SLR, digitalni SLR(DSLR) i kompaktni digitalni aparati su oprema kojutriste nudi prakti arima za najrazli itije zahteve. Me u-tim, najve i broj analiza naglaava prednosti i apostrofi-ra zna aj digitalnih aparata, posebno u snimanju makro

fotografija u stomatologiji. Uvo enje digitalnih aparata u stomatoloku praksu predstavlja vaan korak u budu nost.

Cilj ovog rada je bio da ukae na zna aj fotografijeu stomatologiji, odnosno da ukae na osnovnu tehnologiju

savremenih aparata za fotografiju i analizira prednosti inedostatke danas dostupnih aparata.

Klju ne re i: fotografija, stomatologija, digitalni aparat

Termin fotografija izvedena je iz gr ke re i photos-svetlost, i graphein- crtati. Ovu re je prvi put upotre- bio Sir John F.W. Herschel 1839 godine, ilustrujuci nainsnimanja slika pod dejstvom svetlosti ili slinog zra enjana odgovarajuem osetljivom materijalu.1

Fotografija predstavlja dragocenu pomo u svimoblastima medicine i stomatologije. Smatra se da je foto-grafija u stomatolokoj praksi prisutna pre kao podgrupa uokviru medicinske odnosno klinike fotografije nego kao posebna oblast. No, ovainjenica ne umanjuje njen zna-

aj i sveprisutnost u razliitim segmentima stomatolokihspecijalnosti.2

ta nudi fotografija u stomatologiji? utvr ivanje zdravlja usta i zuba pacijenata pre tretma-

na u cilju blagovremene i tane dijagnoze, potrebnog plana terapije i evaluacije postignutih rezultata

The term photography is derived from the Greekwords photos light, and graphein draw. The wordwas first used by Sir John F. W. Herschel in 1839, to illus-trate the way of taking pictures with the use of light or asimilar radiating agent on a suitable sensitive material.1

Photography is precious support in all areas of medi-cine and dentistry. In the dental practice, photography isviewed as a subdivision of medical, i.e. clinical photog-raphy, rather than a separate area. Nevertheless, this factdoes not lessen its importance and universal applicabilityin various segments of dental specialties.2

How can photography be utilised in dentistry? examination of health status of patients mouth and

teeth prior to treatment, in order to establish timely and

accurate diagnosis, required therapy plan and the eval-uation of results;

SUMMARY Photography offers precious supprot in all areas ofmedicine and dentistry. Usage of photography in dentistryis an integral part of numerous diagnostic and therapeutic

procedures and an important document of progression andoutcome of subscribed therapy. Various types of camerasare available for intraoral and extraoral photography.Market offers different kinds of photographic equipmentto dental practitioners such as cameras with films (Single

Lens Reflex) SLR, digital SLR (DSLR) and compact digitalcameras. However, majority of analyses emphasize advan-tages and relevancy of digital cameras, especially in tak-ing macro photographs in dentistry. Introduction of digital

cameras in dental practice is an important step toward the future.

The aim of this study was to point out the importanceof photography in dentistry, demonstrate basic technol-ogy of contemporary cameras and to analyze advantagesand disadvantages of available cameras.

Keywords: photography, dentistry, digital cameras

Fotografija u stomatologiji

Photography in Dentistry

COBISS. SR-ID 8417026

Dragan Gavrilov, Kosovka Obradovi - uri i

Klinika za stomatoloku protetiku, Stomatoloki fakultet u BeograduClinic for Prosthetic Dentistry, School of Dentistry, Belgrade

INFORMATIVNI RAD (IR)INFORMATIVE ARTICLE

DOI: 10.2298/SGS0604253G

UDC: 616.31:771.31.03 ISSN 0039-1743


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254 Stom Glas S, vol. 53, 2006.

edukativne programe, mogunost validne prezentacijestru nih i naunih radova

reklamiranje dentalnih proizvoda i uslugaFotografije u stomatologiji su ekstraoralne i intraoral-

ne. Fotografisanje spoljanjosti lica i njegovih delova naj-e e ne predstavlja problem i ne zahteva specijalnu opre-

mu ili pristup. Ekstraoralnom fotografijom mogu se bavitiiskusni fotografi, ali isto tako i nedovoljno obueni stoma-tolozi. Sa druge strane, intraoralne fotografije su kompli-kovanije i zahtevaju odreenu opremu i iskustvo. Foto-grafije unutranjosti usne upljine nije mogue kvalitetnonapraviti obinim aparatima, ve su potrebna specijalnaso iva i ogledala. U te svrhe mogu se koristiti aparati safilmom ili digitalni fotoaparati. Uz to, treba znati, da vero-dostojna i reprezentativna foto dokumentacija podrazume-va postupak standardizacije fotografija, korienje istogaparata i istih optikih parametara u svim fazama terapij-

skog postupka.2,3

Digitalne aparate treba razlikovati od digitalnih intra-oralnih kamera. Intraoralne kamere su nastale adaptacijommedicinskih endoskopskih instrumenata. One su sline poobliku i veliini stomatolokim instrumentima to ihini jednostavnim za rukovanje. Iako su vremenom postajalesve kvalitetnije, optike karakteristike intraoralnih kame-ra i rezolucija su slabijeak i od istih osobina prose-nog digitalnog aparata. I pored toga, intraoralne kamere predstavljaju vrlo bitnu kariku u komunikaciji terapeuta i pacijenta u svakodnevnoj praksi. One omoguavaju pre-noenje slike iz usta pacijenta direktno na monitor kojise posmatra, ime se olakava informisanje i upoznava-nje pacijenta sa mogunostima u zbrinjavanju i predloe-nim planom terapije. Posebne prednosti su to intraoralnekamere dolaze u paketu sa integrisanim raunarom, odno-sno ra unarskim softverom koji daje odreene mogunostiadaptacije, odnosno zamrzavanja slike u odreenom tre-nutku a sve u cilju ilustracije predloenog tretmana i bla-govremenog informisanja.3-7

Oprema za fotografisanje

Za kvalitetno fotografisanje u stomatologiji potreb-no je napraviti izbor izmeu 35 mm SLR (Single LenseReflex, jednookih refleksnih) aparata koji koriste film,digitalnih SLR aparata i kompaktnih digitalnih aparata. Neophodno je da aparat poseduje soivo koje omogua-va slikanje iz blizine, blic, a za kvalitetno fotografisanje uintraoralnoj sredini su takoe neophodni ogledala i retrak-tori. Odreeni brend aparata nije od presudne vanosti, alimora posedovati sve navedene funkcije da bi kvalitet bioodgovarajui.1,8

SLR aparati

Osnovne komponente SLR aparata su telo aparata,so ivo i izvor svetlosti, odnosno blic. Refleksni aparati

In educative programmes - enables valid presentationsof expert and scientific works;

In advertising dental products and services.Photographs in dentistry are taken extraorally and

intraorally. In most cases, the photographic recording ofthe face and its parts is not associated with any problemsnd does not require any special equipment or approaches.Extraoral photographs can be taken by experienced pho-tographers and by insufficiently trained dentists alike. Onthe other hand, taking intraoral photographs is a moredemanding task that calls for specific equipment and expe-rience. Photographs of the oral cavity cannot be taken suc-cessfully by ordinary cameras, as they require the use ofspecial lenses and mirrors. Cameras with films or digitalcameras can be used for these purposes. In addition to that,it is important to know that a truthful and representative photo documentation implies the standardisation of pho-tographs, the use of the same camera and the same optic

parametres at all stages of the therapeutic procedure.2,3

Distinction should be made between digital cam-eras and digital intraoral cameras. Intraoral cameras weredevised as a result of adaptation of medical endoscopicinstruments. As to their shape and size, they are similarto dental instruments, which makes them easy to handle.Although their quality has been upgraded over the time,optical performances of intraoral cameras and resolutionsare fairly poor, even when compared with the respectivefeatures of an average digital camera. However, regard-less of these weaknesses, intraoral cameras constitute anessential link in commuinication between dentists ant their

patients in the everyday practice. They enable direct trans-

mission of the picture from patients mouth to the monitorwhere it can be viewed and the patient can be more easilyinformed and instructed of the treatment options and the

proposed therapy plan. A particular advantage of intraoralcameras lies in the fact that they come in package with anintegrated computer, that is with electronic software thatoffers certain options for adaption, i.e. freezing of the pic-ture at a particular point, intended to provide an illustrationof the proposed treatment, as well as timely information. 3-7

Photographic Equipment

For good quality of dental photography, a choice should be made among 35 mm SLR (Single Lens Reflex, single-eyed reflex) cameras with films, digital SLR cameras andcompact digital cameras. It is essential that the camera isequipped with a lens that enables recording from close dis-tance and with flash, while mirrors and retractors are indis-

pensable for good quality of intraoral photographs. A paricular brand of camera should not be viewed as a decisively impor-tant factor, yet it should have all of the aforementioned func-tions in order to obtain an appropriate recording quality. 1,8

SLR Cameras

Basic components of SRL cameras include the bodyof the camera, the lens and the source of light. i.e. the


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koriste ogledalo smeteno izmeu objektiva i filma odno-sno optikog senzora i pentaprizmu u gornjem delu apa-rata. Slika koju fotograf vidi na okularu odnosno LCD(Liquid Crystal Display) ekranu je realna slika objekta. Njihova osnovna karakteristika je u tome to podravajuzamenu objektiva i uglavnom bre reaguju od ostalih foto-aparata.

Popre ni presek SLR aparata prikazuje kako se sve-tlost, prolaze i kroz sistem so iva (1) reflektuje na ogle-dalu (2) i projektuje na mat ekranu za fokusiranje.(5)Preko kondenzuju eg so iva (6) i unutranje refleksi-

je u pentaprizmi (7) slika se pojavljuje na okularu.(8) U postupku fotografisanja ogledalo se kre e u smeru streli-ce, zatvara ine povrine 3 se otvara i slika se projektujena film (4). 1,8 (Slika 1.)

flash. Reflex cameras are equipped with a mirror placed between the objective and the film, i.e. the optic sensor, aswell as with a pentaprism in the upper part of the camera.The picture seen by the photographer thourgh the ocular,i.e. on the LCD (Liquid Crystal Display) screen is a realis-tic picture of the object. The basic feature of these camerasis that they support replacement of the objective and gen-erally react faster than other cameras.

The cross-section of the camera shows how the light, passing through the system of lenses (1), is reflected on themirror (2) and projected on the matte focusing screen (5).Through the condensating lens (6) and internal reflection inthe pentaprism (7), the picture appears on the ocular (8). Asa photograph is being taken, the mirror moves in the direc-tion of the arrow, the shutter of the focal surface (3) opensand the picture is projected on the film (4). (1,8) (Figure 1.)

Slika 1. Popre ni presek SLR aparata sa prikazom smera svetlosti Figure 1.Cross section SLR of the camera

Osnovna razlika izmedju klasinog (35 mm) SLRaparata i digitalnog SLR-a je u tome da je film zamenjenCCD (charge-coupled device) ili CMOS (complementarymetal-oxide semiconductor) senzorima slike, odnosnododata je elektronska podrka koja stvara fotografiju usamom aparatu. Savremeni SLR aparati takoe imaju digi-talan softver koji izotrava i dodatno poboljava kvalitetfotografija.

SLR aparati imaju TTL (through the lens) merenje,odnosno tehniku kojom se meri nivo svetlosti kroz soi-vo kamere. Time se kontrolie koliina svetlosti kojae seemitovati iz blica, merenjem intenziteta svetlosti koja padana senzor blica kroz soivo aparata. Kada je fotografijadovoljno osvetljena zatvara se automatski zatvara.1,2

Za dobre fotografije, soiva treba da imaju minimumaperture (otvora blende) od f22, a najbolje bi bilo f32, stozna i malo svetla u jedinici vremena. Ona se takodje bira- ju zavisno od daljine predmeta fotografisanja. Soiva od100 mm fokalne duine obezbeuju fotografije dovoljne

veli ine bez ugroavanja pacijentovog prostora i komfora.Iako so iva sa automatskim fokusom nekada mogu vrlo

A basic difference between a classical (35 mm) SLRcamera and a digital SRL lies in the fact that the film has

been replaced by CCD (charge-coupled device) or by CMOS(complementary metal-oxide semiconductor) picture sensors,namely an electronic support has been introduced, which pro-duces a picture within the camera itself. Likewise, contem-

porary SRL cameras are equipped with digital software that

sharpens the picture and additionally improves its quality.SRL cameras also have a TTL (through the lens)

measuring system, namely a technical device that allowsthe light level to be measured through the lens of the cam-era. In this way, the quantity of light released from theflash is controlled by measuring the intensity of the lightcast through the camera lens on the flash sensor. When the photograph is sufficiently illuminated, the shutter closesautomatically.1,2

Good photographs call for lenses with a minimumof f22 aperture (opening in the lens that admits the light),while a f32 aperture, meaning a small amount of light per

time unit would be optimal. The choice of lenses is alsodetermined by the distance of the object photographed.


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256 Stom Glas S, vol. 53, 2006.

dobro da poslue, intraoralna sredinaesto moe da zava-ra sistem za fokusiranje proizvodei nezadovoljavajuerezultate.1,3,8-10

Nedostatak digitalnih aparata je to to slika koja sedobije ne odgovara onoj koja se vidi u trenutku fotogra-fisanja, ve je to slika sa malim zakanjenjem, za ta jeodgovoran softver aparata. Logino, kanjenje je mini-malno ili ga uopte nema kod 35 mm SLR aparata, neto je ve e kod digitalnih SLR-a, a najvee kod kompaktnihdigitalnih aparata. Problem kod digitalnih aparata je i kon-tinuirano fotografisanje, odnosno softverska obrada svakefotografije ponaosob to dodatno oduzima vreme u uslovi-ma ne ba prijatnim za pacijenta. (Slika 2.)

100 mm focal length lenses ensure sufficiently sized pho-tographs, while the patients space and comfort are notimpaired. Although lenses with automatic focus can some-times be of good service, the intraoral environment mayoften have a misleading effect on the focusing system,resulting in a poor performance.1,3,8-10

On the other hand, a shortcoming of digital camerasis that the obtained picture does not match the one seen by the photographer while being taken. Instead of that, the picture appears somewhat delayed, which should be attrib-uted to the shortcomings of the camera software. Logical-ly, in 35 mm SRL cameras the delay is either minimal ornonexisting, it is somewhat bigger in digital SRLs, whileit is the biggest in compact digital cameras. Another prob-lem associated with digital cameras is related to continu-ous photographing, i.e. the software processing of each photo is carried out separately, which further consumes

the time in the situations that can hardly be comfortablefor the patient. (Figure 2.)

Slika 2. Digitalni SLR aparat Figure 2.Digital SLR camera

Me utim, u doba savremenih informacionih tehnolo-gija digitalni aparati nude mnogo vie mogu nosti stomato-lozima u svakodnevnoj praksi od aparata sa filmom. Jednaod osnovnih i najbitnijih je LCD monitor. On se nalazi nazadnjoj strani svakog aparata i omogu ava trenutno posma-tranje dobijene fotografije, i ukoliko je potrebna korekcija,odmah se moe ponoviti fotografisanje, to kod aparata safilmom nije mogu e do razvijanja filma. Svi digitalni apa-rati imaju ugra en autofokus to osigurava otrinu foto-grafije. Kvalitetniji aparati imaju i stabilizatore slike ime

je dodatno olakano rukovanje aparatom, posebno kodzumiranja i fotografisanja gracilnih detalja u usnoj uplji-ni. Vano je napomenuti da digitalni aparati za skladitenjefotografskih zapisa koriste memorijske kartice. One mogu

biti razli itog memorijskog kapaciteta omogu avajuci skla-ditenje i do nekoliko stotina fotografija.

Rezolucija i opti ke karakteristike digitalnihaparata

Piksel je najmanji element digitalne fotografije i kada

se sloi mozaik piksela razliitih boja dobija se digitalnafotografija. Ukoliko se pomnoi horizontalni sa vertikal-

However, in the era of modern information technolo-gies, digital cameras represent better choice than those withfilms, as they can provide dentists with far wider range of

possibilities to be applied in their professional daily rou-tine. One of these basic and most essential possibilities isan LCD monitor. Situated at the back of every camera, itenables momentary observation of the picture obtained; if acorrection is needed, the recording can be repeated, whichcan be done with a film camera only after the film has beendeveloped. The sharpness of the image is ensured by theinbuilt autofocuses, which are common in all digital cam-eras. Higher-quality cameras are also equipped with picturestabilisers, which additionally facilitate handling, particu-larly while zooming and photographing tiny details in theoral cavity. It is important to note that digital cameras usememory cards for photographic record storage. These cardscan have various memory capacities, allowing storage of asmany as several hundred photographs.

Resolution and optical features of digitalcameras

Pixel is the smallest element of a digital photograph;

pixels of different colours are arranged in a mosaic to con-stitute a digital image. If the number of horizontal pixels


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nim pikselima dobija se ukupni zbir (povrina) koja seizraava u milionima piksela odnosno u megapikselima(MP). Na primer, fotografija na aparatu sa 3 megapikselase sastoji od 2,048x1536=3,145,728 piksela. Poveanjem broja megapiksela poveava se i rezolucija slike.

Megapikseli ili rezolucija ne moraju obavezno dadaju zadovoljavajui kvalitet fotografije. Boja i tonalitetsu mnogo znaajniji sa tehnike strane. Stoga nisu retkislu ajevi da aparat sa manje MP proizvodi bolje fotogra-fije nego drugi sa veim brojem piksela. U sutini, brojmegapiksela ne predstavlja nita drugo do mogunostiuveli anja dimenzija fotografije a da se ne izgubi otrinafotografije. Optiki zum predstavlja vrlo bitnu karakteri-stiku svakog aparata, meutim u stomatologiji kod izotra-vanja predmeta koji su ve blizu, dubinska otrina se gubito zna i da bez dodatnih objektiva dobijena slika nee bitiotra.

Makro(macro) fotografija je fotografija koja nasta- je kao posledica fotografisanja iz blizine. Moe se defini-sati kao fotografijaiji je odraz na filmu ili elektronskomsenzoru iste veliine ili vei od samog objekta fotografisa-nja. Me utim, u savremenoj fotografiji, pojammakro imaizmenjeno znaenje, odnosno kamera ima mogunost dafokusira toliko da na fotografiji 10x15 mm objekat budeiste veli ine ili vei.3,10,11

Za fotografisanje u makro modu SLR aparatimaneophodna je dodatna optika oprema. To su specijalna,takozvana, makro soiva (neki ih nazivaju i mikro) , kojaimaju mogunost fotografisanja iz blizine. Ona su naje eoptimalizovana za odnos 1:1 , ali postoje i soiva nekih proizvo a a koja mogu da uveliaju i do odnosa 5:1imese i najsitnije strukture kao to su oi insekata ili snene pahuljice mogu zumirati u neverovatan fokus.3

Kod digitalnih kompaktnih aparata su za tu svrhu proizvo a i uvrstili softversku opciju macro (obeleenuruom), koja omoguava fotografisanje predmeta iz apso-lutne blizine bez potrebe za dodatnim zumiranjem. Kada je aparat umacro modu otvor blende je najmanji i postiese velika dubinska otrina. Medjutim, koriscenjemmacroopcije kod ovih aparata javlja se problem osvetljenja,odnosno zbog apsolutne blizine objektiva aparata ostajevrlo malo prostora za svetlost. Ovo je posebno vano zaintraoralne snimke koji zahtevaju dubinu i otrinu pri foto-grafisanju.

Objanjenje za prednosti digitalnih kompaktnih apa-rata nad SLR aparatima sa filmom, kod snimanja makrofotografija, je vrlo jednostavno. Definicija dubinske otri-ne je arina duina objektiva odnosno dijagonalaipa ilifilma. Digitalni aparati imaju dijagonaluipa (senzora)oko 5 puta manju od dijagonale 35 milimetarskog filma,to zna i da je dubinska otrina na istoj blendi 5 puta vea.Drugim reima, digitalni aparati koji i sa dodatnim objek-tivima imaju maksimalnu blendu nekoliko puta manju od

SLR aparata, daju fotografiju umacro modu najmanjeistog, ili boljeg kvaliteta.1,8

are multipled with vertical ones, total (surface) expressed inmillions of pixels is derived, i.e. in megapixels (MP). Forexample, a photograph taken by a 3 MP camera is com-

posed of 2,048x1536=3,145,728 pixels. When the numberof pixels is increased, the image resolution is increased as

well. Megapixels or resolution need not necessarily pro-vide a satisfactory image quality. From the technical point,colour and tonality are far more important. Therefore, it isfairly common that a camera with smaller MP capacity pro-duces better images than those with larger pixel capacities.Basically, the number of pixels does not mean anythingexcept the indication of the extent to which the dimensionsof an image can be increased without affecting its sharp-ness. An optical zoom is a very important feature of anycamera type; in dentistry, however, it is important to notethat, as the sharpness of an already close object is increased,the depth dimension of the image becomes less sharp,which leads to the conclusion that the obtained picture willlack sharpness unless additional objectives are used.

A macro photograph is obtained at close range. Itcan be defined as an image whose reflection on a film oron an electronic sensor is of the same size as, or biggerthan, the object photographed. Still, the meaning of theterm macro has been changed in contemporary photog-raphy, since cameras focusing capacities allow for theobject recorded in a 10x15 mm photo to be of the samesize or even bigger.3,10,11

Taking macromode pictures with SRL camerasrequires additional optical equipment. These are special,so-called macrolenses (sometimes also referred to as mic-rolenses), which enable video recording at close range.Although lenses are commonly optimised for 1:1 ratio,some manufacturers offer those capable of providingan increase to as much as 5:1 ratio and therefore allow-ing even the tiniest structures (e.g. insects eyes or snow-flakes) to be zoomed into incredible focuses.3

In digital compact cameras, the aforementioned pur- pose is met by the introduction of amacro software option(marked with a rose), which enables objects to be record-ed at the closest possible range without the need for addi-tional zooming. When a camera is set to amacro mode,the aperture is the smallest, while high levels of sharpnessare achieved. On the other hand, the use ofmacro option

in these cameras is associated with the problem of illu-mination, namely due to the absolute vicinity of the cam-eras objective too little room is left for the light. Intraoralrecords call for depth and sharpness.

When macro photographs are taken, it is very simpleto explain the advantages of digital compact cameras overSRL cameras with films. The definition of depth sharpnessis the focal length of the objective, i.e. the diagonal of thechip or of the film. The diagonal of a chip (sensor) in a dig-ital camera is around 5 times smaller than that of a 35 mmfilm, meaning that the depth sharpness with the same aper-ture is 5 times bigger. In other words, digital cameras, whoseminimal aperture, even with additional objectives, is several

times smaller than that in SRL cameras, produce macro pho-tographs of at least the same, if not of a better quality. 1,8


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258 Stom Glas S, vol. 53, 2006.

Ogledala

Kod intraoralnog fotografisanja neophodno je koristi-ti specijalna ogledala. Ogledala za stomatoloko intraoral-no fotografisanje mogu biti od poliranog metala ili ogle-

dala prekrivena staklom sa prednje povrine. Obe vrstedaju zadovoljavajue rezultate. Ogledala se mogu nai utri razli ita oblika zavisno od potrebe korienja u ustima ito: palatinalno, bukalno i lingvalno. U zavisnosti od uzra-sta mogu biti za odrasle ili za decu.3,12

Zbog velikog znaaja koji imaju o ogledalima se posebno mora voditi rauna da bi se postigli zadovoljava- ju i rezultati. Ogledalo se naje e uva na sobnoj tempe-raturi a da bi se dobila dobra intraoralna fotografija onomora biti zagrejano do temperature tela. Na taj nain e sespre iti magljenje kada se unesu u usta. Ogledalo mora bitisuvo i isto pre svakog fotografisanja tako da ni najmanja

kap te nosti na ogledalu ne umanji kvalitet fotografije.Zbog materijala od koga su izraena ogledala (staklo ili polirani metal) lako se mogu ogrebati, to zahteva posebnu panju u njihovomi enju i uvanju.10,12-14 (Slika 3.)

MirrorsThe use of special mirrors is indispensable in intraoral

video recording. Mirrors for intraoral video recording indentistry can be made of polished metal or with glass cov-ering their front surface. Both types provide satisfactoryresults. Mirrors come in three different shapes dependingon whether they are to be used palatally, buccaly or lin-gually. As to the patients age, there are those intended foradults, as well as for children.3,12

Due to their exceptional importance, mirrors should be devoted particular attention, since they are essential forsatisfactory results. Mirrors are commonly kept at roomtemperature and for a good intraoral image, they should bewarmed to the body temperature. This will prevent themfrom fogging when inserted into the mouth. Prior to itsuse, the mirror should be clean and dry, because the imagequality could be compromised by a slightest drop of liq-

uid possibly left behind on the mirror surface. Due to thematerial they are made of (glass or polished metal), mir-rors can easily get scratched, and therefore call for particu-lar care while cleaned or stored.10,12-14(Figure 3.)

Slika 3. Palatinalno i bukalno ogledalo Figure 3.Platinal and bucal mirror

Slika 4. Plasti ni retraktori Figure 4.Plastics retractors


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Retraktori Za lake fotografisanje odreenog polja unutranjosti

usne duplje korienjem ogledala, neophodni su odgovara- ju i retraktori usana. Zbog nepoeljne refleksije svetlosti, plasti ni retraktori su se pokazali poeljnijim od metal-nih.3 (Slika 4.)

OsvetljenjeDa bi se osigurao maksimalan kvalitet i verodostoj-

nost u fotografisanju upotreba blica predstavlja imperativ.Dnevna svetlost ili reflektor na stomatolokoj stolici nisudovoljni i nee dati zadovoljavajue rezultate. Blic moe biti manuelni, koji zahteva kalibraciju u razliitim situaci- jama, ili automatski.

Tako e, blic moe biti kruni (ring), iz jedne take(point light) ili kombinacija ova dva sistema. Ring blic je vrlo jednostavan za korienje jer ne baca senku kod

intraoralnih fotografija. Svetlo je uniformno i sa malimkontrastom. Blic iz jedne take, koji se nalazi kod svihkompaktnih digitalnih aparata, prua takoe vrlo zadovo-ljavaju e rezultate. Ova vrsta blica baca odreenu senku ive eg je kontrasta od ring blica. Ovo je poeljno u nekimslu ajevima npr. kod registrovanja promena, odnosno ano-malija sluzokoe usne duplje. Pravac pruanja svetlosti blica treba odrediti u zavisnosti od senke koju daju obrazii usne, da ne bi dolo do preklapanja senke sa zubima itkivima u dubini usne duplje.3,9,10,12,13

Osvetljenje ponekad moe predstavljati i problem. Neki aparati mogu zumirati objekat toliko blizu da gadodiruju prednjom povrinom soiva.To je skoro bez izu-zetka sluaj kod kompaktnih digitalnih aparata gde su pro-izvo a i unapredilimakro opti ke karakteristike (ak do0 mm), ne raunaju i na fotografisanje u uslovima nedo-statka adekvatne svetlosti kakav je sluaj u stomatolokimordinacijama. Tada je nemogue osvetliti povrinu izmeuobjekta i soiva to ini fotografisanje iz apsolutne blizinenepraktino i neadekvatno. Da bi se dobilo vee rastojanjeizme u objektiva (odnosno blica) aparata i objekta moguse koristiti telefoto macro soiva fokalne duine 100-200mm, ime se omoguava adekvatno osvetljenje. U ovimslu ajevima je posebno indikovano koristiti ring blic. Uskorije vreme pojavili su se ring blicevi sa LED (Light-Emitting Diode) osvetljenjemime je omogueno konti-nuirano osvetljenje macro fotografije.13,14( Slika 5.)

Danas je poznato da se digitalne fotografije lakomogu menjati i prilagoavati sopstvenim potrebama korienjem odgovarajucih raunarskih softvera koji su pri-sutni na tristu. To moe biti prednost ukoliko je potreb-no iskorigovati kontrast ili boju. Meutim, te prednostise u klinikoj stomatologiji mogu i zloupotrebiti ime sedovodi u pitanje autentinost fotografije. Imajui ovo naumu, neke kompanije su poele da ugrauju u svoje apa-rate softverski sistem koji dodaje digitalni vodeni ig sva-koj fotografiji. Ukoliko se fotografija promeni na rauna-

ru odgovarajui softver detektuje oteenje vodenog igaime se potvr uje neautentinost fotografije.

RetractorsWhen mirrors are used in video recording of certain

fields inside the oral cavity, the process is significantlyfacilitated with suitable lip retractors. Due to the undesiredlight reflectons produced by metal retractors, they have proved to be less suitable than plastic ones.3 (Figure 4.)

IlluminationFor maximum quality and truthfulness of a video

recording, the use of flash is mandatory. The daylight or areflector are not likely to produce satisfactory results on adentists chair. There are either manually flashes, which needto be calibrated in different situations or automatic ones.

Likewise, there are ring flashes and point light flash-es, as well as those combining these two systems. A ringflash is very easy to handle as it does not cast a shadow inintraoral imaging. The light is uniform and with little con-trast. A point light flash, which is found in each compactdigital camera, can also provide fairly good results. Whileflashes of this type cast some shadow, they produce highercontrasts than ring flashes, which can be desirable in cer-tain cases, e.g. when changes or anomalies in the oral cav-ity mucous membrane are to be registered. The directionof the flashlight extension should depend on the shadowcast by the cheeks and lips, so as to avoid the overlappingof the shadow with the teeth and tissues in the depth of theoral cavity.3,9,10,12,13

The illumination issue can sometimes be associ-ated with certain problems. Some cameras are capable ofzooming the object so close as to touch it with the lens

front surface. This is almost invariably the case with compact digital cameras, wheremacro optical features have been significantly upgraded (even up to 0 mm), while pos-sible lack of adequate light, as it is likely to be the case indental offices, has been largely disregarded. In such situ-ations, it is impossible to illuminate the surface betweenthe object and the lens, which renders the video recordingfrom absolute vicinity impractical and inadequate. Largerdistances between the objective (i.e. the flash) and theobject are achieved with the use of telephoto macro lensesof the focal length ranging from 100 to 200 mm, whichenable adequate illumination. In such cases the use of aring flash is particularly indicated. Recently, ring flashes

with LED (Light-Emitting Diode) illumination have beenoffered by some manufacturers and continuous illumina-tion ofmacro photos has become possible.13,14 (Figure 5.)

Nowadays, it is well known that digital photographs caneasily be modified and accommodated according to anyones

particular needs by means of adequate electronic softwaresystems available on the market. This may be an advantagein cases when contrast or colour corrections are needed. Onthe other hand, these advantages can easily be abused in den-tistry, where the image authenticity may become highly ques-tionable. Having this in mind, some companies have recentlyoffered cameras with inbuilt software systems that provideeach picture with a water seal. If the image is modified in the

computer, the appropriate system detects the damage of thewater seal, thereby proving its inauthenticity.


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