Saturday, July 7, 2012

What in the world is the orthodontist looking at when he or she evaluates my teeth?!?!

Orthodontists usually have the basic goal of achieving Angle's Six Keys of Occlusion in any of our comprehensive orthodontic cases.  Dr. Edward Angle is considered the "father" of modern orthodontics and essentially created the orthodontic specialty by opening the first school focused on orthodontics only in 1900.  He noted that function (the way the bite works) and form (the way the teeth and bite look) go hand in hand and wrote a paper on the aspects of tooth positioning that resulted in the most ideal form and function.  While there have been a few modifications to the original Six Keys since, Dr. Angle was remarkably accurate in his descriptions.

So, when an orthodontist evaluates a person's bite and tooth positions, he or she is comparing the current positioning versus the Six Keys of Occlusion.  Occlusion basically means the way the teeth fit together.

Angle's Six Keys to Occlusion
bulletKey I – Molar Relationship
bulletKey II – Crown Angulation (tip)
bulletKey III – Crown Inclination (torque)
bulletKey IV – Rotation
bulletKey V – Spacing
bulletKey VI – Curve of Spee

The photo above illustrates dental casts with ideal occlusion (inter-digitation of teeth) and ideal overbite/overjet.  

 The following link provides a great explanation and pictures for each of the Six Keys:

So, when many patients think they should be finished with treatment when their teeth are straight, just remember that orthodontists are specially trained to go the distance and achieve both a great looking smile and a bite that fits together and functions in the most ideal way.  Orthodontists also evaluate jaw relationships, anterior/posterior and vertical positioning of the teeth relative to the face, and soft tissue form (lips especially), but the Six Keys truly are the key to the best orthodontic treatment in most cases.