Guide for Achieving Excellence in Dental Photography: The Indirect or Mirror Intra Oral Views

Written on 03/25/2018
Masoud Abu Zant

The purpose of this article is to review the lingual, full occlusal and quadrant occlusal photographs using dental mirrors. These photographs are relatively easier to achieve than the buccal views, a final list containing the eight photographs most needed for a well-documented initial examination is proposed.

1. THE LINGUAL LATERAL VIEW

Magnification:

1:1 or life size. Number of teeth involved: first premolar to second molar. Depth of field at aperture f/22 and magnification 1:1 is 3mm.

Material:

Only one uncut clear plastic cheek retractors, and the foot shaped double sided Rhodium coated mirror is advised, . Mirror size may vary according to the clinical situation. A box of Kleenex, hot water, suction, air syringe and operatory light.

Camera position, mirror position and where to focus for maximum sharpness:

Bring the chair down slightly so that you can look down into the patient’s mouth. When the patient opens wide the plane of his mandibular teeth should be parallel to the floor. The camera is oriented at about a 45 degree-angle to the mirror surface. The mirror is approximately at a 45 degree-angle to the lingual plane of the teeth. Unless you are dealing with a narrow constricted mandibular arch or a significant macroglossy, the proper angle is easily obtained. Best focus is performed at the first molar.

Technical hints:

This view is actually less difficult to achieve than it seems. Although two retractors may be used, I found the use of one clear plastic retractor to be adequate. The retractor will be pulling the lower lip downward, anteriorly and outwardly,.

Have the patient hold his head straight for the right side view and have turn it to his right side for the left side view. Then, gently introduce the mirror sideways and tilt it back vertically as you push the tongue back. The mirror should not touch the last molar. The proper angle of view is finally obtained by tilting the superior edge of the mirror toward or away from the lens. For difficult access, use the small end of the mirror, , instead of the longer end, .

Frame orientation and composition:

The buccal cusp’s edges should run horizontally near the horizontal midline of the slide frame. The photograph typically includes the 1st bicuspid to the 2nd Molar. Some of the occlusal surface is visible.

Note that the use of a metal retractor would be more noticeable. Don’t be concerned with the extraoral background appearance, it will simply appear as black in the photograph.

Flash position and flash choice:

For single source flash, rotate the flash at 3 o’clock for the right view and to 9 o’clock for the left view. The Nikon Dual flash system is placed horizontally. Flash position is irrelevant for all ring flash type of illumination.

2. THE PALATAL LATERAL VIEW

Magnification:

1:1 or life-size. Number of teeth involved: First premolar to second molar. Depth of field at aperture f/22 and magnification 1:1 is 3mm.

Material:

Only one uncut clear plastic cheek retractors and the foot shaped double-sided Rhodium coated mirror is recommended. Mirror size may vary according to the clinical situation. A box of Kleenex, hot water, suction, air syringe and operatory light.

Camera position, mirror position and where to focus for maximum sharpness:

Patient’s chair is raised and the chair slightly tilted back. The head is straight or slightly to the right for the right view but turned completely to the right for the left view. The retractor will be pulling the upper lip upward, anteriorly and outwardly. The mirror is gently inserted so that its posterior border is approximately one centimeter from the hamular notch and its anterior edge touching the contra-lateral first bicuspid. Therefore the mirror is about a 45-degree-angle to the photographed palatal side. The camera lens will be at a 45-degree angle to the mirror.

the mirror will also be tilted. The bottom edge being more toward the camera lens. Last, try to place the most convex part of the mirror on the bottom. This will facilitate the procedure. Best focus is at the first molar second premolar region.

Technical hints:

Have your patient keep his tongue down and be careful not to impinge on the upper lip with the mirror edge. The further away the superior edge of the mirror from the dental midline, the less likely you will catch a glimpse of the direct image of the teeth.

Frame orientation and composition:

The buccal cusp outline should follow the horizontal lower 1/3 of the photograph. Some of the occlusal surface is visible.

Flash position and flash choice:

For single source flash, rotate the flash at 3 o’clock for the right view and to 9 o’clock for the left view. The Nikon Dual flash system is horizontal. Again for the single flash users remember the key principle: keep the flash on the mirror side.

3. THE PALATAL ANTERIOR VIEW

Magnification:

1:1 or life size. Number of teeth involved: Upper left to upper right cuspid. Depth of field at aperture f/22 and magnification 1:1 is 3mm.

Material:

Two cut clear plastic cheek retractors, the heel shaped double sided Rhodium coated mirror or the small occlusal mirror are recommended. Mirror size may vary according to the clinical situation. A box of Kleenex, hot water, suction, air syringe and operatory light.

Camera position, mirror position and where to focus for maximum sharpness:

You can approach this photograph in two ways. The front and the back approach. I prefer the back approach for two reasons. The patient is already positioned for three pictures: the maxillary occlusal view, the lateral occlusal quadrant view and the anterior maxillary lingual view. I find this position more effective to orient my mirror without catching a direct view of the incisal edges or the patient’s nostrils. For the front approach, the patient is reclined at about a 45-degree angle from the horizontal plane. The cut plastic retractors are held in an upper and outward direction.

The mirror should be placed as parallel to the palatal surface of the incisors as possible so that the camera lens is almost at a 90-degree angle to the mirror plane. For the back approach, the patient’s chair is reclined horizontally and the patient is tilted back slightly. Move the chair up so you don’t have to bend over excessively. The mirror is held as horizontal as possible to be almost parallel to the palatal surfaces of the upper incisors. Best focus is achieved on the lingual surfaces of the incisors.

Technical hints:

Retractors, lip, patient’s nose should be absent from the picture.

If you are using the large portion of the heel shaped mirror, make sure you are not catching the edges in the frame. Keep the mirror parallel to the incisal edges axis so the image isn’t tilted. It may be easier to use the large portion of the heel shaped mirror and to rest its edge against the mesial surface of the second bicuspid for better stability and easier mirror inclination.

Frame orientation and composition:

The maxillary lingual surfaces should be centered and display symmetry from one cuspid to the other. This view is interesting for visualizing the amount of incisal wear present. The resulting background is usually dark or black.

Flash position and flash choice:

On the front approach, the flash is at 3 or 9 o’clock, depending where you want the shadow to
be projected. Make sure the upper incisors are not between the light and the mirror view. From the illumination standpoint the back approach is also easier to control when the flash is at 3 or 9 o’clock. If you are using the Nikon dual flash system, simply place the dual flash horizontally for both approaches. Again, ring flash position is irrelevant.

4. THE LINGUAL ANTERIOR VIEW

Magnification:

1:1 or life size. Number of teeth involved: Lower left to lower right cuspid. Depth of field at aperture f/22 and magnification 1:1 is 3mm.

Material:

Two cut clear plastic cheek retractors, the small heel double-sided Rhodium coated mirror is recommended. Use a mirror whose end fits behind the biscuspid area. Mirror size may vary according to the clinical situation. A box of Kleenex , hot water, suction, air syringe and operatory light.

Camera position, mirror position and where to focus for maximum sharpness:

Bring the chair up and tilt it so the mandibular occlusal plane forms a 30-degree angle with the horizontal, (floor), when the patient opens wide. The retractors are held apart, downward and outward. The larger part of the mirror is placed and held as vertically as possible behind the lower incisors. The camera lens comes slightly from above. Best focus is achieved on the lingual surfaces.

Technical hints:

This view is actually more difficult than its maxillary counterpart. For correct mirror placement it is essential for your patient to open as wide as possible. This eliminates retractor and lip visibility. Although, you will realize that as the patient opens wide, the retractors have a tendency to come up with the lips. You’ll need to ask your patient to pull them down again. There is a fine balance between lip retraction and the possible amount of opening.

Frame orientation and composition:

The lower incisal edges should roughly follow the horizontal superior third of the photograph. Depending on arch curvature the first biscuspids may be partially included. The view should be symmetrical from left to right. With narrow arches, it may be impossible to totally hide the lip and the retractors from showing.

Flash position and flash choice:

Place the single source flash at 12 o’clock. Position the Nikon dual flash system horizontally.

5. THE MAXILLARY ARCH OCCLUSAL VIEW

Magnification:

1:1.8 (x 0.55) to 1:2 (x 0.50) or half life size. All the maxillary teeth are displayed. Depth of field varies at aperture f/19 from 6.5 to 7.5mm and f/16 from 5.5 to 6.5 mm depending on the chosen magnification.

Material:

Two cut clear plastic cheek retractors, the occlusal double sided Rhodium coated mirror is recommended. Mirror size may vary according to the clinical situation. A box of Kleenex, hot water, suction, air syringe and operatory light.

Camera position, mirror position and where to focus for maximum sharpness:

The patient’s chair is totally reclined, his head slightly tilted back. The operatory light is moved to facilitate framing and focusing. Your position is right behind the patient. This exposure is probably one of the most common along with the lower full arch mandibular occlusal view.

Here again two techniques are described: the frontal approach and the back approach. Although you can obtain the desired result using both, I would be inclined to rely on the clinician’s experience for this matter. Teaching dental photography and making a few photographs to illustrate a point is one issue; practicing and applying the techniques everyday with your patient is another one. The front approach requires the patient seated in a semi upright position.

Holding the mirror in this position and obtaining consistent framing is more difficult. The back approach is simpler and more predictable. The patient is holding the retractors outwardly and upwardly. Upon mirror insertion, quickly adjust the proper magnification to the arch size and ask your patient to open as wide as possible. The advantage here is that you can help the patient open by pushing down gently on the mirror.

Ideally, the mirror should be at a 45-degree angle to the teeth plane and the camera at a 45-degree angle to the mirror plane so that the resulting angle is as near as possible to a 90-degree angle. In this situation the depth of field available provides a sharp image on all the teeth. Best focus is achieved on the occlusal surface of the second premolar.

Technical hints:

Make sure the retractors are cut short enough so the mirror doesn’t bind when inserted. Best results are obtained by using a larger mirror. Hold the mirror from underneath by its edges and make certain that the mirror is not touching the occlusal surface of the second molars.

Frame orientation and composition:

The image should be centered and display all teeth including part of the buccal surface of the maxillary anterior teeth. The longer and narrower the arch form the more difficult the picture. Conversely, a short square arch form allows you to crop or increase the magnification, therefore eliminating unwanted background. Ideally, minimum lip and retractors should be invisible.

Flash position and flash choice:

For the front approach with a single flash, put the flash at 3 or 9 o’clock. Have the patient pull the retractor on the flash side a little more so the light is not partially blocked. For the back approach, position the flash between 11 and 1 o’clock. The shadows cast are insignificant. If you are using the Nikon dual flash system, place the flash horizontally and no shadow will be seen.

6. THE MANDIBULAR ARCH OCCLUSAL VIEW

Magnification:

1:1.8 (x 0.55) All the mandibular teeth in occlusal view. Depth of field varies at aperture f/19 from 6.5 mm to 5.5 mm at f/16.

Material:

Two cut clear plastic cheek retractors, the occlusal double sided Rhodium coated mirror is recommended. Mirror size may vary according to the clinical situation. A box of Kleenex , hot water, suction, air syringe and operatory light.

Camera position, mirror position and where to focus for maximum sharpness:

Patient is tilted back at about a 50-degree angle and asked to tilt his head back. The mandibular occlusal plane should make at least a 45-degree angle with the floor when the mouth is open wide. Ideally the mirror is positioned at a 45-degree angle to the teeth plane and the camera lens at a 45-degree angle to the mirror. The retractors are held in a downward and outward direction. Best focus is achieved at the second premolar area.

Technical hints:

Suction the excess saliva, dry the teeth and proceed promptly especially for this view. Insert the mirror gently pushing the tongue behind it. Make sure the distal edge of the mirror is not touching the last molars or pressuring the tissue.

Frame orientation and composition:

The full lower arch should be centered and the labial surfaces of the anteriors should be visible. The lip and retractors should be out of view.

Flash position and flash choice:

Position the single source flash on 3 or 9 o’clock. If the patient has a wide opening you can position the flash at 11 or 1 o’clock. The Nikon dual flash system is placed horizontally.

7. THE POSTERIOR QUADRANT OCCLUSAL VIEW

Magnification:

1:1 or life size. Number of teeth involved: first premolar to second molar. Depth of field at aperture f/22 and magnification 1:1 is 3mm.

Material:

Two cut clear plastic cheek retractors, the large foot shaped double sided Rhodium coated mirror is recommended. Mirror size may vary according to the clinical situation. A box of Kleenex, hot water, suction, air syringe and operatory light.

Camera position, mirror position and where to focus for maximum sharpness:

The patient is in the same position as for
the full maxillary occlusal view. This position works for making photographs of all four posterior quadrants. Your place is on the patient’s right side for all photographs as well. Maxillary occlusal quadrants: The cut retractor is placed so that the cut part is down. This allows you to put the mirror without interference. The retractor is pulled outwardly and upwardly. The convex portion of the mirror is on the cheek side. The mirror is inclined about 45-degrees to the teeth plane. Best focus is obtained at the second premolar-first molar region. Proceed quickly as holding the camera steady for those who are right handed can be tiring.

Mandibular occlusal quadrants: The cut retractor is placed with the cut part upward. The patient pulls the retractor outwardly and downwardly. The mirror is inserted without pushing back on the tissue and oriented ideally to a 45-degree angle to the teeth plane. Best focus is obtained at the second premolar-first molar region.

Technical hints:

For the lower quadrants, ask your patient to lift their tongue and then gently push it away with the mirror as you put it in place.

Frame orientation and composition:

The occlusal quadrant, including the second molar to the first bicuspid or cuspid, should run straight in the middle of the frame in the horizontal plane. No lip or retractor should be visible. Increased magnification allows you to uncover more details.

Flash position and flash choice:

For the maxillary quadrants, place the single source flash at 1 or 2 o’clock and at 10 or 11 o’clock for the mandibular quadrants The Nikon dual flash system will be placed horizontally for all quadrants.

CONCLUSION

The purpose of this article is to review in detail the technique involved in making indirect mirror lingual, full occlusal and occlusal quadrant photographs. Not all the views described are useful for every patient. I would recommend adding to the series the two following photographs:

1. The full occlusal maxillary view, magnification comprised between 1:1.8 or (x 0.55) and 1:2, (x 0.5).

2. The full occlusal mandibular view, magnification around 1:1.8 or (x 0.55).

I wish to conclude this series on 35mm dental photography by suggesting eight photographs I believe to be essential in documenting our initial clinical examination. These photographs should be part of the data collected along with the clinical examination, study models and radiographs for the purpose of establishing a reference, diagnosis and a treatment plan. Our memory can be of short duration and is often altered as time passes. It will clarify and solve many legal disputes to refer to a set of before and after treatment photographs. Recently, B. Touati insisted on the importance of making high quality photographs by pointing out that, “clinicians may address (treatment) concerns and render a successful treatment unfortunately compromised by improper lighting or photographic techniques that fail to document the efficacy of the approach.”8

This series teaches you the fundamentals, the materials and the techniques involved in dental photography. Certainly, my goal is to help you develop confidence in making good and consistent photographs using the very best 35mm clinical camera system available. Technology is ever evolving and in the June issue of Oral Health 1998, I pointed out the development of the latest digital cameras.3 Digital cameras are not a fad. They are here to stay and represent the future of imaging. Prices are dropping and quality is improving almost on a monthly basis. Reviews and testing of the newest and most current digital camera systems is underway! I look forward to sharing with you all the new exciting technology of this remarkable camera.

THE ESSENTIAL VIEWS FOR A COMPREHENSIVE INITIAL DOCUMENTATION

1. The anterior horizontal or vertical full face. Magnification: Vertical 1:10 to 1:8/ horizontal 1:10, (x 0.10) 2. The anterior smile view. Magnification: 1:2, (x 0.5) 3. Intermediate or tight anterior view in maximum intercuspal position. Magnification: 1:1.6 (x 0.62) or 1:1.4 (x 0.71) 4. Intermediate view with upper and lower teeth slightly apart. Magnification: 1:1.6 (x 0.62) 5. The lateral 3/4 view teeth in occlusion. Magnification around 1:1.3 or (x 0.75) 6. The lateral 3/4 view teeth slightly apart. Magnification around 1:1.3 or (x 0.75) 7. The full occlusal maxillary view. Magnification comprised between 1:1.8 or (x 0.55) and 1:2, (x 0.5) 8. The full occlusal mandibular view. Magnification around 1:1.8 or (x 0.55)