Bennett Angle... What's the Point???

[Boetlaar]

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So I've come across a few old questions regarding Bennett Angle and I can't seem to wrap my head around it. The def is the angle made between the saggital plane and the pathway of the non-working condyle during working movement... I can now (finally) visualize what this is... BUT WHO CARES??

How would this effect a restoration (cusp heights? groove placement?)

How would being Class II effect this (Increase/Decrease Bennet Angle)

Anything else useful (I am curious not just for the boards but also for being a dentist(funny how those can be separate))🙂

 

[DrTacoElf]

So I've come across a few old questions regarding Bennett Angle and I can't seem to wrap my head around it. The def is the angle made between the saggital plane and the pathway of the non-working condyle during working movement... I can now (finally) visualize what this is... BUT WHO CARES??

How would this effect a restoration (cusp heights? groove placement?)

How would being Class II effect this (Increase/Decrease Bennet Angle)

Anything else useful (I am curious not just for the boards but also for being a dentist(funny how those can be separate))🙂

It has a huge effect on cusps. If you neglect it your crowns will have interferences all over them for one thing.

 

[skulpcha]

So I've come across a few old questions regarding Bennett Angle

How would this effect a restoration (cusp heights? groove placement?)

How would being Class II effect this (Increase/Decrease Bennet Angle)

Anything else useful (I am curious not just for the boards but also for being a dentist(funny how those can be separate))🙂

Most restorative concepts in dentistry were derived through trial and error over the years during the early 20th century when " the giants" were working out how to rehabilitate complete edentulism with dentures with the least harmful sequelae. Guys like House, Bennett, Monson, Schuyler and others were all working out what different things apparent in the machinery of mastication meant such as static and dynamic occlusion, protrusion etc etc. One engineer from New York ( via South Africa) named Hanau in particular came up with a bunch of rules ( and a semiadjustible articulator that was workable -- there have been numerous articulators over the years that that just were'nt practical) to reasonably restore a patient and overcome most problems including considerations to 1. the condylar plane angle, 2. the incisor angle ( anterior guidance on protrusion) 3. the height of the cusps (posteriors) 4. the plane of occlusion 5. the compensating curve ( curve of spee of the mandible.)

Bennett side shift is just another dimension in the articulator that attempts to record the working movements of a patient in order to avoid restoring a case that either harmfully restricts movement or disrupts natural phenomena such as group function canine guidance etc. After all those years of these old timers pulling their hair out it was established that dentures sit on movable " compressable" tissues and rigid conforming with these rules dont matter on free floating dentures. Crown and bridge is a dfferent story.

If a patient is edentulous and has a class 2 occlusion the mandible is further back that otherwise such that there is more play in the protrusive movement. In such a situation you don't want to restore this case with teeth that have very high cusps because there would be helluva more cuspal destabilization of the denture on dynamic movement ( on protrusion or to the side) actually zero degree is best in class 2 and a semiadjustable articulator is unnecessary in these cases. Hope this helps🙂