by Clayton A. Chan, DDS, MICCMO
One of the main things that I have communicated with each and dental technician that has done my full mouth restorative cases over the years is that I want and need a gnathological and anatomical occlusal wax up. Why?
Over the years while practicing restorative/TMJ dentistry I have found that the central nervous system of the human body demands specific senses in the bite that allows one to feel comfortable and stable. Without these proprioceptive occlusal feelings of stability, balance and a solid even bite, the human being may experience difficulty in finding ultimate quality of physiologic rest. Some individuals are more particular about what they feel than others. Some individuals central nervous (CNS) system demands a higher level of precision to function comfortably than others. This is what the dental profession does not fully understand in general.
Once the dentist has stabilized and proven the bite relationship between the upper teeth and the lower arch of teeth a bite registration can be recorded without torques and skews. I recommend to all dentist who are interested in physiologic precision to record the bite in a sitting up right position rather than a laying down (supine) position. It is this registration that the laboratory technician depends on to continue the precise bite management process to meet the proprioceptive demands of the patient/client.
The dental technician uses specialized wax to shape, mold and carve the upper and lower arch form, shape and surfaces of each tooth that should simulate comfortable function and resting modes to the central nervous system. A re-architecting of the complete occlusal table, smile line, positioning of each tooth, and their relationship to one another is often required in the severely debilitated worn dentition. Optimal ccclusal waxing often requires more than creating a crown/tooth shape to cover the prepared tooth form, but often requires the occlusal/biting surfaces to fit the opposing dentition as well as support a proper positioned mandible and temporomandibular (TMJ) joint and disc relationship.
Anatomical occlusal morphology matters. Establishing contact points in wax prior to final pressing and or casting matters. It is not just to look good, but even more, contact points established on incline planes when synchronized together as a unit allows the mandible to know where is home base. If there are premature contacts in the bite during the final stages of occlusal adjustments, the central nervous system will proprioceptively find them and will cause grinding and clenching.
This means that I don’t want the following:
- I don’t want over contoured crowns
- I don’t want flat looking occlusal anatomy
- I don’t want rounded bulbous looking gingival necks
- I don’t want chicken scratch occlusal anatomy
- I don’t want wide occlusal molar anatomy
- I don’t want the lingual cusp tips to be higher than the buccal cusp tips
- I don’t want the mesial lingual axial contours of the first bi’s to be bulk
- I don’t want bicuspid drop offs in my occlusal tables
- I don’t want the lower anteriors to be higher than the posterior occlusal tables of the bi’s and molars (re: deep curve of Spee)
In other words this is what I want: My Prescription
- Natural occlusal cusp fossa form
- I want the gingival necks of each tooth to have a normalized emergence profile (the tooth needs to look real not fake).
- I like steep looking cusp fossa form – reason being is that after adjustments things can start looking flat.
- The occlusal anatomy should look really anatomical, not some man made occlusal anatomy…it should look like a real bi or a real natural molar….Not a crown!
- I want the cusp tips to line up and have a natural symmetry to them yet they are asymmetric and individualized – natural in appearance…not stock standard form.
- I am not interested in trying to match the opposing anatomy. If the opposing is flat I don’t match flat. I always want anatomical form.
- I want my embrasure form to be opened up so it looks natural and esthetically pleasing…Too many lab crowns close up the embrassure spaces causing the group of restorations to look fake, blocked in and unnatural.
- I want natural lingual anatomy even on the non functional surfaces…including the lingual surfaces of my anteriors – uppers and lowers….flat surfaces on the lingual of the anteriors is not acceptable to me.
- I want a normalized occlusal tables…I believe those of you who have come to OC courses have seen my occlusal tables of many of my cases during my lectures. The case has to have anatomical form that functions well and looks great.
Proper forum will result in proper function. Abnormal form leads to abnormal function.
** Waxing Up and Porcelain work by Las Vegas Esthetics – Ray Foster Team – Master waxer – Dragos Cobori
© 2009 Clayton A. Chan, DDS. All Rights Reserved.