How to classify a dental occlusion.
For the vast majority of dentists and orthodontists, dental occlusion has been classified using the molar relationship as well as the canine relationship. However, a Complete Dentist looks at occlusion in a slightly different manner. A Complete Dentist looks at occlusion starting with the joint position first.
Dr. Dawson has created a classification system in relation to the joint position and how the teeth relate to each other. This should not be confused with the Piper classification. The Piper classification strictly talks about a classification related to intracapsular disorders, whereas the Dawson classification starts with the relationship of the joint and how the teeth relate to each other.
There are six classifications:
Dawson Type 1: Maximum intercuspation is in harmony with centric relation. Here, you can load the joints firmly and there will be no hit and slide, as the occlusion is completely equilibrated.
Dawson Type 1A: Maximum intercuspation is in harmony with an adaptive centric posture. Over time, the joint can go through changes, and this creates an adaptive phase. Joints can be loaded with firm tension or tenderness, and there's no symptoms.
Dawson Type 2: Condyles displace from a verifiable centric relation position into maximum intercuspation. Here, loading the joints with bimanual manipulation will result in firm loading and no tension or tenderness. You will see the patient slide out of centric relation into maximum intercuspation. Please note that this you will find in most of your patients when you use bimanual manipulation correctly.
Dawson Type 2A: The condyles have to displace from an adaptive centric posture into maximum intercuspation. This is very similar to Class 2, however, in the case that there is no centric relation verification, but we have an adaptive centric posture position.
Dawson Type 3: Centric relation cannot be verified. When we think about this category, it can't be verified because your patient may experience tension or tenderness. In that case, we need to treat those conditions first and then try to reverify if we can establish centric relation.
Dawson Type 4: The occlusal relationship is in a state of progressive disorder due to pathology within the temporomandibular joints. What you will find here is you may find an open anterior bite. You might find asymmetry. Here, in these particular cases, we must establish a stable joint position before doing any restorative correction. Remember, as a complete dentist, occlusion starts with the joint position, specifically, centric relation. Centric relation is verified using a technique called bimanual manipulation. When this is done correctly, the Dawson classification system works really well.
Learn about to Identify all type of occlusion in our foundational lecture Functional Occlusion - From TMJ to Smile Design.