I have to start by apologizing. My main purpose in this blog is to help viewers get as much out of their clinical photography as possible, however, this topic is one that simply cannot be mastered in words alone. Sure, I can give tips about how to get that perfect lateral or occlusal shot, but until you get a chance to have the mirror properly aligned or camera angle corrected, all the reading in the world won't get you there.
Let me try my best, though. In this post, I'll cover the lateral arch shots, and deal with the occlusals some time in the near future.
I'll start with the criteria that I think best define what I like to look for when I take a "great" lateral image. I want to capture every tooth in that side of the arch from the second molar to the contra-lateral central incisor. Additionally, I would like to see the plane of occlusion run right down the center of the horizontal axis of the image. It's also important that the lens be angled such that we aren't looking up or down on the arch. Last, but most importantly (at least in my humble opinion), I would like to see the arch perfectly perpendicular to the viewer; I have to be able to see the Angle's Classification properly. Unfortunately, it is this last criteria that is often the most underachieved. Open any dental journal today, and I will guarantee you that you will see lateral arch shot after lateral arch shot where the teeth are not even close to perpendicular. This gives a false sense of the Angle's classification which is a critical factor for proper treatment planning.
As my previous post mentioned, I believe that current mirror design has a lot to do with the difficulty in achieving a better image. Nonetheless, I think that human error plays a bigger role. I say this because I can almost always get a great image with the current mirrors, however, my students have found that there is a rather decent learning curve.
The keys for operators achieving successful images lies in the positioning of the mirrors and retractors. It is vital that the mirror be placed as far distally as possible and the distal end be pulled away from the second molars before pivoting the mesial end facially. This keeps it from hurting the patient.
The contra-lateral retractor should be released to the mid-line as much as possible to get rid of as much tension as possible not related to the side you are capturing.
Last, but not least, don't be afraid to really stretch that mesial end of the mirror until a perfect image appears. Collagen is our friend and will allow us to capture a perfect image on almost everyone. Don't be afraid of "stretching" the patient, as you can go pretty far without hurting them. Sure, it's going to be a weird experience for them, but it won't be painful, unless of course, you don't pull the mirror away from the distal-most aspect as you pivot it.
By far, the most common mistake that I see from my students is the fear of pivoting that mirror to where it needs to be. All "newbies" are afraid to really stretch the patient. In my courses, when a student tells me that they have a patient stretched as far as possible but still can't get that great shot, I gently assist them in moving the mirror even farther to get what is needed. Afterwards, patients remark that it didn't hurt at all.
There are time, though, where anatomy just won't allow a "perfect" shot. In times like these, I would rather miss the second molar altogether and get a true Angle's classification, rather than capture the second molar, but not get a fair evaluation of the occlusal relationship.
Remember, this particular type of image requires hands on instruction and lots of practice to get it perfect. I look at it like driving a car; You can read about it as long as you like, but until you get behind the wheel, shift the car into "Drive" and step on the accelerator, you just don't truly understand what you've gotten yourself into and how to overcome unexpected issues.
I hope this helps, and I welcome any feedback.
Have fun shooting images. It will change your practice forever.