Oral photography

Question 1

List 5 reasons why it is important to take clinical photographs

Answer 1

• It serves as a pre-treatment record for medico-legal purposes
• Helps serve as a documentation for progress; before and after
• Informs treatment planning
• Provides visual information for patients
• Serves as a form of communication between practitioners. For example, if a patient has recession, you as the clinician can send their oral photographs to a specialist to determine if they should have the gingival graft. It can therefore serve as something that can be used in lieu of a physical consultation

Question 2

List the four records required to make an orthodontic diagnosis

Answer 2

• A clinical exam and assessment
• Good quality intra and extraoral photos
• Radiographs; panoramic and lateral cephalometric films
• Study models (molds or 3D imaging)

Question 3

List the 3 types of profiles extra-oral photographs taken

Answer 3

• Side profile (can take both sides)
• Frontal view
• Can take one of patient smiling

Question 4

List the 6 types of intra-oral photographs taken

Answer 4

There will be six photos:
• One of the patient keeping their mouth in centric occlusion
• Patient slightly opening mouth
• Mandibular occlusal view
• Maxillary occlusal view
• Lateral aspect of bite with mouth in centric occlusion

Question 5

State what goes into the clinical notes regarding the oral photographs (2)

Answer 5

• The state of the dentition before any intervention is noted. For instance, tooth discolorations, enamel defects, gingival recessions, fracture
• Fillings and composites are noted

This is to protect the clinician from legal issues

Question 6

Explain why it is important to take photographs for patients

Answer 6

• Some patients may not understand the need for a particular treatment like jaw surgery, and may only want braces
• Photographs can be edited to show patients what the end result of treatment would be like
• This can help inform and convince them for the need for particular treatments

Question 7

List the 2 pieces of equipment required for dental photo

Answer 7

• A macro lens (60- 100mm) that allows us to move in close

* A light source that is close enough to the lens but does not cast shadows on the subject

Question 8

List the advantages (1) and disadvantages (1) of ring flash

Answer 8

Ring flash
Advantages:
• Easy to achieve good results, especially when taking shots of the challenging molar regions

Disadvantages:
• Results in plasticity: separate parts of an image are in different focus

Question 9

List the advantages (2) and disadvantages (1) of twin flash

Answer 9

Twin flash
Advantages:
• Provides better results
• Light output is higher resulting in larger depth of field and illumination. • It makes the image more three dimensional

Disadvantages

• For every single shot, the reflectors need to be checked and corrected

Question 10

List the 3 important accessories needed for an intraoral radiograph

Answer 10

• Lip and check retractors
• Photograph mirrors (can be made of metal or surface coated glass)
• Contrasters (black backgrounds behind teeth which remove distracting background and improve the image)

Question 11

Define depth of field

Answer 11

• The zone of acceptable sharpness in front of and behind the subject on which the lens is focused
• Simply put: how sharp or blurry is the area behind your subject.

Question 12

Define aperture and its effect on the image

• Large aperture

- Small aperture

Answer 12

Definition:
• Refers to the opening of a lens’s diaphragm through which light passes
• By controlling the amount of light coming into the image, we can control its brightness

Large aperture:
• Indicated by a small number
• This results in less depth of field and a blurrier background

Small aperture:
• Indicated by a large number
• This results in a greater depth of field and a sharper background

Question 13

State the aperture required for intraoral and extraoral photographs in terms of the f number

Answer 13

Intra-oral:
•We want everything to be focus
•Therefore, a small aperture is desired AKA large f number

Extra-oral:
• We only want the patients face to be in focus
• Therefore, a large aperture is desired AKA small f number

Question 14

Define shutter speed

Answer 14

• A camera takes a photograph by exposing a digital sensor to light
• The shutter is a barrier that keeps light out when you’re not taking a photo
• Pressing the button at the top of the camera opens the shutter, and when the shutter is open, an image is recorded
• When the shutter closes, the camera stops recording.
• The shutter speed, then, is just how long that barrier stays open to let light into the image
• Shutter speed is how long an image is exposed to light — it can be milliseconds, or even minutes

Question 15

State the shutter speed required for intraoral and extraoral photographs

Answer 15

• Shutter speed can affect exposure and blurring
• Handheld photography requires a shutter speed of at least 1/ 160th of a second to 1/125th of a second (when flash is on)

Question 16

Define ISO and its effect on a photograph

Answer 16

Definition:
• Measures the sensitivity of the image sensor to the amount of light present

Effect:
• The lower the number the less sensitive your camera is to light and the finer the grain
• Higher numbers mean your sensor becomes more sensitive to light which allows you to use your camera in darker situations. The cost of doing so is more grain

• Set this at 100 for minimal grain

Question 17

State the position of the clinician when taking an intra oral and extra-oral photograph

Answer 17

• Adjust patient chair to your height
• Ensure the camera is directly above/ or in line with the aspect being photographed
• Clinician can stand

Question 18

State the specifics of a frontal view intraoral photograph (3) and state the effect of an uncentered occlusal plane

Answer 18

Specifics:
• The occlusal plane should be in the middle of the photograph
• In addition, the midline of the maxillary arch should be centred in the middle of the photograph
• All the teeth should be visible

Effect:
• If the occlusal plane is not centred (i.e, the camera was to high or too low when positioned), it can distort the perspectives of the incisors (may cause it to look like there is a huge overbite when there isn’t)

Question 19

State the specifics of a lateral view intraoral photograph (2)

Answer 19

• Photographs should be perpendicular to the lateral teeth (with the aid of a mirror)
• Occlusal plane should be parallel to the horizontal frame of the photograph

Question 20

State the specifics of a mandibular/ maxillary intraoral photograph (2)

Answer 20

• For these views, get patients to hold their breathe as breathing can fog up mirrors
• For the mandible, have the patient place their tongue behind the mirror

Question 21

State the specifics for taking extraoral photographs (4)

Answer 21

• Patients should tied their hair back so that the jaw line can be exposed. Hair can cover the jawline and prevent an accurate diagnosis/ from picking up asymmetry
• Patient should be in their natural head posture with their natural occlusion
• There should be no shadow in front of the patient
• Sometimes, we might get the patient to bring their jaw forward to see how the profile improves to determine which appliance is best suited for them