The Dawson Academy Blog

While many in the profession maintain that bimanual manipulation is too hard to learn, after they are taught the correct technique, dentists attending The Dawson Academy find it not only learnable and repeatable, but choose it as their preferred method for finding and verifying centric relation.

One of the keys to success with bimanual manipulation is visualizing the anatomy of the joint, and knowing and understanding the proper definition of centric relation is critical to this ability. There are many misinterpretations of the true definition of CR; in fact Wikipedia lists 16 different definitions. 

Provisional restorations play a far more important role than just a transitional role while the laboratory fabricates the definitive restoration.  Of course they function to protect the dentin and pulp from thermal, chemical, mechanical and bacterial damage, but there is much more. 

One of our most important decisions in our dental treatment planning process is the treatment position of the TMJ. An easy and effective adjunctive screening tool for TMJ Health is Doppler Auscultation.

Listening to our patient’s joints is an important step in the TMJ-Occlusal Exam process. The use of a Doppler in dentistry was developed in the 1980’s by Dr. Mark Piper. It is basically a stethoscope with a microphone that incorporates the Doppler wave effect. The sounds give us an indication of the amount of friction and quality of lubrication within the joint.

Technique

1. Place gel on the transducer head and place between middle of the ear and  condyle in the fovea
2. Turn on the volume on the Doppler MD2 from Great Lakes
3. When you hear the sound of the Superior Temporal Artery, angle the transducer anteriorly toward the posterior aspect of the condyle.
4. Ask the patient to open and close slowly.
   
   • If there are no sounds, we can assume that the patient has an intact joint that is well lubricated.
   • If there are noises, Is it a medial pole issue or lateral pole issue?
5. Medial pole is tested by having the patient place their tongue on the roof of their mouth and just open half way. The motion will be pure rotation.
6. Lateral Pole noises are distinguished by having the patient open wide and close, then have the patient move to right, left and protrusive, which are all in Translation.

The following are the Piper Classifications:

• Class 1 – normal joint
• Class 2&3—lateral pole issues
• Class 4 &5 – medial pole issues

Integration of Doppler Exam into Treatment Planning Decisions

If the patient presents with a Piper Class 1 and NO signs of occlusal instability, then the patient can be restored in their Habitual Occlusion.

If the patient’s exam presents with a Piper Class 2 or 3, then a lateral pole problem exists and we must decide how to establish Occlusal Stability.

A Medial Pole issue indicates a Piper Class 4 or 5. It should flash a caution warning that further investigation is warranted.  A MRI or CAT scan is indicated to make a definitive diagnosis. The TM Joint must be stable before restorative phase is initiated, barring Phase 1 treatment.


In conclusion, Doppler Auscultation is an important screening tool that is efficient, inexpensive and informative.