Clinical photography

By Dr Tony Pious

CLINICAL PHOTOGRAPHY

CONTENTS

1. Introduction

2. Basic Terms

3. Clinical Requirements for Photographic Records

4. Taking Clinical Photographs

5. “After Shot”-Post Processing your Digital Images

I. Why taking photographic records in orthodontics?

The basic orthodontic record taking is comprised of three man types of records,

a) STUDY MODELS

b) RADIOGRAPHS

c) CLINICAL PHOTOGRAPHS

BENEFITS OF TAKING CLINICAL PHOTOGRAPHS

• More and more emphasis from the orthodontic community on the

achievement of balanced facial harmony and smile esthetics of our

patients, in addition to the traditional orthodontic goals of a well-

aligned and functional dentition.

• The need for proper clinical photographic records of the

orthodontic patients has become more obvious and essential for

proper treatment planning and follow up.

• Helps orthodontist to study the existing patient’s soft tissue

patterns during treatment.

• To assess lip morphology, smile arc and smile esthetic.

• Helps to plan treatment without the presence of patients.

• Need of photographic records for research and publications,

lecturing and presentation.

• Medico legal cases cannot be over emphasized.

WHY GO DIGITAL?

• The right choice in this digital age.

• Easy to use, eg- retake ,delete. Immidiate result.

• Cost effective-no more film, no more developing,.

• Easy to store,all u need is a generous memory card and

reasonable size hard disk.

• The main advantage is the ability to enhance ,or ‘post-process’

the images.eg- rotation,color,brightness etc.

BASIC TERMS1) RESOLUTION

• It describes how much details an image can hold.

• Based on the pixel count and bit depth of each pixels.

• Each pixels displays one color, as the number of pixels

increases, the image details becomes sharper.

• A camera resolution is calculated by the number of

megapixels its digital image sensor is capable to capture.

• A display resolution is expressed in pixels per inch(ppi)

and a printers resolution in dots per inch(dpi).

• Minimum camera resolution for orthodontic purpose

would be 4 MP, can be more.

2) FOCAL LENGTH

• An important attribute of a lens than its quality, is its focal length.

• Its technically defined as the distance from the part of the optical path

where the light rays passing through onto the image plane or the digital

image sensor.

• This distance is usually measured in millimeters.

• Focal length can be thought of as the amount of magnification of the lens.

• The longer the focal length , the more the lens magnifies the scene.

• In addition with magnification, the focal length determines the prespective

and compression of the scene.

3) APERTURE

• It is a hole through which the light passes from the subject to the film.

• Various sizes of apertures are called

‘f’ STOPS or ‘f’ NUMBERS.

• Size rages from 1.4-32

• These numbers are a measure of the size of the lens aperture, NOT the diameter of the aperture.

• It is the number by which the focal length of the lens must be divided to yield the aperture diameter.

• For Eg. 50mm lens is set to f/2 aperture, diameter of the aperture is 50/2 = 25mm.

• ‘f’ stands for focal length.

4) SHUTTER SPEED

• It reffers to the amount of time the shutter is open or the digital

image sensor is activated.

• The exposure of the image is determined by the combination of

shutter speed and the opening of the apeture.

• Shutter speed is displayed as fraction of a second,such as 1/8 or1/250.

CLINICAL REQUIREMENTS FOR PHOTOGRAPHIC RECORDS

1) DIGITAL CAMERA

TYPE OF DIGITAL CAMERAS

• Two main types of camera

• Point & Shoot digital camera

• DSLR ( Digital Single Lens Reflex )

• DSLRs are what professional photographers currently use as they allow

maximum flexibility and customization for the highest possible quality of digital

images.

• There are many cameras from both spectrum that are suitable for orthodontic

record taking purposes, however ,this section will focus on their two most

important general requirements for any camera chosen; the ring flash and the

macro lens.

LENS

• Fish eye lens

• Wide-Angle lens

• Normal lens

• Telephoto lens

• Macro lens

MACRO LENS

• Macro photography refers to close up photography, the classic definition that the image projected on the film plane is the same size as the subject.

• Many point n& shoot cameras have a macro function; a function that allows to take a close up shots of objects in good focus and depth of field.

• This is not entirely satisfactory for great and consistant results every time.

• But a dedicated macro lens attached to a DSLR camera provides even better close up photos with high definition and better focus.

RING FLASH VS POINT FLASH

• The point flash may sometime produce fairly good

light distribution when used for clinical photographs.

• Detracting shadows ,which may also obstruct

important details ,which are often irreparable using

image editing software and will detract from the final

quality of the image.

• In contrast, the ring flash eliminates such shadows

by allowing a more and even thorough distribution of

light during extra oral and intra oral photographs, and

thus the quality of the image is enhanced.

• So its highly recommended to use a ring flash for

orthodontic photography.

2) SPECIAL CHEEK RETRACTORS• Recommended cheek retractors for best results in clinical photography is double ended

retractors.

• Two types of double ended retractors- with regular and small size on either side.

- with narrow end and wide end.

• Smaller one piece orthodontic bonding retractors are generally not a good choice for

orthodontic purposes, especially for buccal and occlusal shots, as they have less

retraction potential and it can be painful experience.

• Its recommended to buy a good quality retractors to ensure durability and reliability, with

recurrent disinfection procedures.

3) DENTAL PHOTOGRAPHY MIRRORS

• Many types of mirrors have been used

ranging from front-silvered mirrors to

highly-polished stainless steel mirrors.

• Front-silvered mirrors offer the best quality

image and light distribution, no ghost

image or double layering.

• light reflection on front-silvered mirrors

brightens, bright image as an end result.

• Its also preferred to use ‘long handled’ mirrors as

they allow better control and handling.

• There are different sizes for use with different

patients depending on the age and mouth-

opening size. Medium size would fit with most

patients.

• Mirrors with out handle may be used successfully

but are more tricky to handle ,especially when

handling an expensive camera with the other

hand.

TAKING CLINICAL PHOTOGRAPHS

HOW MANY PHOTOGRAPHS DO WE NEED?

• There is no standard set that is universally approved as a rule of thumb.

• Based on many authorities opinions in this field –that a complete Clinical

photographic Set for any orthodontic patient at ant stage of treatment should include

a minimum of NINE photographs- FOUR Extra oral and FIVE Intraoral Photographs.

• Extra –oral clinical photographs are the easiest to take, only require proper

positioning of the patient and clinician, in addition of course to the digital camera

setup itself.

• Itra-oral photos require proper cheek retractors,dental photography mirror.

A) EXTRA-ORAL PHOTOGRAPHS

• Extra oral photos consists of four shots:

1) Face-Frontal ( lips relaxed).

2)Face –Frontal (smiling ).

3)Profile (Right side preferably-

lips relaxed).

4)Profile 45° ( oblique ).

• These four shots provide the clinician with informations about

patient’s facial and soft tissue features,propotions and smile esthetics.

1) FACE_FRONTAL(LIPS RELAXED)

• The first extra oral photo usually taken,

probably the easiest-however there are some

important guidelines that need to be taken.

• Framing of the shot

• Should encompass the whole of the patient’s

face and neck

• Reasonable margin of space all around.

• Hold the camera lens in vertical position.

• Stand in a reasonable distance away from the

patients.

• The Patient should be made to stand with their head in the Natural

Head Position,with eyes looking straight in to the camera lens.

• The patient should hold their teeth and jaw in a relaxed position.

• Make sure patient’s head is not tilted or their face rotated to either

side; the shot should be taken at 90° to the facial midline from the

front.

• Ensure the patient’s inter-pupillary line is level.

• Recommended to make the patient stand in a plain dark or white

background.

2) FACE_FRONTAL (SMILING)

• Same guidelines as for the Face-frontal shot.

• Important thing that the patient should be Smiling in a natural way,

with the teeth visible.

• Helps in visualizing the patient’s smile estheics and soft tissue

propotions.

3) PROFILE ( RIGHT SIDE- LIPS RELAXED )• The profile photo has a high diagnostic

value to the orthodontist.

• After taking frontal face photo, the patient is asked to bodily turn to their left,thus getting the right profile side .

• The head should be in the natural position,with their eyes fixed horizontally.

• The wrong head position can make a confusion regarding the patient’s actual skeletal pattern.

• Face clearly visible with no obstructions and use ring flash.

4) PROFILE 45º ( OBLIQUE )

• This shot conveys the patient as if in social interaction, and can

give valuable information about the smile esthetics changes pre

and post-treatment.

• From the profile photo position, the patient is asked to turn their

head slighty to their right,while keeping their body still in the

previous profile position.

B) INTRA – ORAL PHOTOGRAPHS

• This requires more attention to detail to produce good results.

• Use of special cheek retractors and dental mirrors are required .

• There are five required intra oral photographs:

1) Frontal ( In Occlusion )

2) Right Buccal ( In Occlusion )

3) Left Buccal ( In Occlusion )

4) Upper Occlusion

Mirror Shots

5) Lower occlusion

1) FRONTAL ( IN OCCLUSION )• Patient seated comfortably and raised to the elbow level of the clinician.

• Using the retractors, patient’s lips are retracted Sideways and away from the gingiva, towards the clinician.

• Maximum visualization of the teeth and alveolar ridges.

• Photo taken 90º to the facial mid-line.

• High F value setting is recommended to attain maximum depth of the shot with even the last visible molars are focused. F 28.

• Ring flash helps in light distribution of the image with out shadows,especially in the deeper part of the oral cavity and buccal vestibules.

2) RIGHT BUCCAL ( IN OCCLUSION )• Flips the right retractor o the narrower

side,while the left retractor remains in place as for the previous frontal shot.

• The right retractor is stretched to the extend that the last molar is visible if possible.

• 90º to the canine-premolar area for best visualization of buccal segment relationship.

• Important in orthodontic assessment.

3) LEFT BUCCAL ( IN OCCLUSION )

• Similar to the right buccal shot.

• The left retractor is stretched maximum to the left with the patient’s head turned to right side.

4) UPPER OCCLUSAL

• Dental mirrors come into play.

• With the lip retractors the upper lip is retracted sideways and away from the teeth.

• The mirror is inserted and pull it slightly downwards to get the maximum visibility of the upper arch.

• The patient is asked to breath only through nose to avoid fogging of mirror.

• The patient is instructed to lower the head slightly and shot taken 90º to the plane of the mirror.it is recommended that thee mid palatal raphe is used as a guide for the orientation of the shot to get it levelled.

• Avoid finger visibility.

5) LOWER OCCLUSAL

• Lower lip is retracted sideways and away from teeth using lip retractor.

• Mirror is inserted and lifted upwards for maximum visibility.

• The patient is aske to roll back the tongue behind the mirror so that it won’t interfere the visibilty of any teeth.

TIPS

• The direction of pull of the retractors is always sideways and away from tissue,to get maximum visibility.

• Wetting the retractors before insertion eases positioning them and reduce patient discomfort.

• Warming the mirror in warm water prior to insertion helps to prevent Fogging of the mirrors which prevent clear image .

• Use saliva ejector to eliminate saliva prior to each photograph.

• Its recommended to take photographs before impression taking to eliminate the possibility of material stuck between the teeth.

THE AFTER- SHOT: POST- PROCESSING YOUR DIGITAL IMAGES

• Once all photographs taken, next step is to download it to the

computer for some minor editing and image correction.

• Create separate folders for each patients and store in the hard disk.

• Can use a dedicated database within a propietary orthodontic

imaging software.

• Back-up the files( CD, DVD, Google Drive ) is a safe method to avoid

loosing of the datas, which can be restored when needed.

• Image editing can be done using suitable image editing

softwares.

• The most popular one is Adobe Photoshop.

• Basic editing functions are enough for orthodontic purposes.

• Microsoft’s Preview, Paint. Net (windows), Fast stone Image

viewer (windows), Preview and iphoto ( Apple Mac ).

1) IMAGE EDITING

EDITING WITH IMAGE EDITING SOFTWARE

• For orthodontic purposes, a few number of editing procedures are recommended.

• Flipping( Mirroring ) and Derotation- vertically or horizontally

• Cropping- removing unnecessary image informations.

• Color, Brightness and Contrast

• Scratch removal

• Saving image files

FLIPPING AND DEROTATION

• It should be the first step in editing images.

• before flipping after flipping

CROPPING

• Removes all unnecessary parts of the image like retractor, lips, fingers

COLOR, BRIGHTNESS AND CONTRAST

• Slight adjustments in color and brightness highlights the details.

• There is no specific adjustment here as the adjustment to be

made are variable depending on how the image is taken.

SCRATCH REMOVAL

• Sometimes dust particles attached to the camera CCD sensor.

• Minor scratches on the mirror.

• Removed using scratch removal tool in image editing softwares.

• Healing tool and patch tool in Adobe Photoshop.

SAVING YOUR IMAGE

• Its done after all editing.

• Dedicated folders can be made for each patient.

• Labelled by date.

• There are many formats to save image.

• Two main formats used is:

• TIFF- Tagged Image File Format.

• JPEG- Joint Photographic Experts Group.

SAVING IMAGES FOR PUBLICATIONS AND ON- SCREEN PRESENTATION

• In on-screen presentations very high resolution images are not necessary.

• Large file size increase loading time and slow perfomance.

• Recommended resolution is 72-96 DPI.

• For printing and publications, resolutions should be more.

• Range 150-300 DPI.

THANK YOU