We featured the following Question and Answers in our March 2016 newsletter.
Dr. Danilo Strumendo from Sydney, Australia, asked if we could forward a question to some dental experts, which we gladly did.
There's not a huge amount of occlusion teaching going on in Australia right now and being 7,000 to 10,000 miles away from the US teaching centers doesn't make it easy to find mentors who can answer those questions that begin to nag - am I doing the right thing?
The people we asked:
Drs Aubé, Bolt, Wilkerson and Reid quickly and generously shared their perspectives and have agreed we can share their answers with you.
Remember - these are quick, "hope this is helpful" type answers, not treatises on the subject but I think they provide useful insights!
You might also consider:
- How would you answer the question?
- Do you have similar experiences and how do you deal with them?
THE QUESTION - From Dr. Danilo Strumendo
I am seeing a high incidence of patients in their late teens and early twenties with worn canines and a resultant group function , abfractions, tooth wear on posterior teeth.
I always recommend splints for these patients.
That is obviously protecting their teeth at night butshould I be looking to equilibrate and build up worn canines with composite so their posteriors don't crash into each other during day time function?
In my opinion yes you should be looking at equilibrating. However, I would make sure that the TMJ’s are stable before. To do so…You should eliminate all contacts from the posterior teeth by slightly over grinding the splint but only so that a thin 20 micron marking paper will barely slide through when the patient clenches.
Go to youtube and type : « plaque occlusale parfaitement equilbree »…you’ll find my one minute video [text is linked to save you time] that explains what I just wrote. [Narration is in French but it's pretty obvious what is happening: patient is asked to retrude and close, and Dr. Aubé checks for space between the splint and back teeth on both right and left, then has the patient slide right, left and forward and confirms with the patient that they are touching the front of the splint and not the back.]
Once you’ve overground the splint let the patient go for a month…night time wear only and make sure the patient understands that he/she must not keep the tongue between the teeth.
If after the first month the paper slides…go ahead and equilibrate…
If after the first month the paper doesn’t slide…then re-adjust…
but this would mean that there is instability….
so in this case you need to see the patient every month and re-adjust until finally one month the paper slides…
because there was some instability…
you have to make sure that the newly achieved stability is durable….
hence, in this case, the need to get three consecutive months of sliding paper.
After the month check the splint with the same marking paper…if it still slides through go ahead and equilibrate…if not…repeat until it happens…but don’t equilibrate until the paper slides for three consecutive months (you've demonstrated an instability so you need to wait longer to make sure the newly confirmed stability is durable).
When you do equilibrate, don’t overbuild the canines…the patient has flattened his/her envelop of function and may not tolerate a steeper guidance. Rebuild the canine only to make it equal to the steepest posterior angle, then lightly grind the posteriors to get them just barely out of the way.
There are two phases to the operation.
First there is the diagnostic phase. This is to confirm joint stability, ie stable condylar position.
If this is achieved, then you can move forward with bite stabilization phase which is coronoplasty and bonding of composite to worn dentition.
Many times we see young people with TMD as well as worn dentition. Once 6 year molars come into occlusion and there is a para functional habit you will see worn dentition.
Remember that there is a third cusp on first molars to aid in lateral guidance prior to the cuspids coming in.
It sounds like you’re describing young people who brux.
If wear is the effect, then we want to know the etiology for long term solutions.
Several things come to mind to be evaluated, let’s call them the ABCD of bruxism/wear:
Airway- is there an airway obstruction at night?
Brain- is there neurologic activity, especially related to meds like amphetamines(Parkinson-like in older)?
Constricted anterior guidance?
Dysfunction- Occlusal interferences in C.R. and/or excursions?
We evaluate all these factors, correct the occlusion, cover dentin exposed areas and, if parafunction persists, use a nightguard or sleep appliance.
Here's my Go To in most cases.
I prefer to avoid splints if at all possible as many patients do not like something between their teeth, making two visits and paying lab fees too.
As Pete Dawson says "all treatment starts at the TMJ".
I verify CR with heavy loading and if I can equilibrate to get CR=MIP without causing harm to teeth that otherwise don't need any restoration, I will. I use bi-manual manipulation and am very comfortable with its predictability.
Once I get two or more contacts on both sides posteriorly and no long centric interferences with client sitting upright, I then look for posterior lateral interferences.
Even though the fangs are worn, they may not need any lingual composite if ther posterior teeth can be tweeted so slightly to just eliminate their contact in side motions.
More often than not, this will cause the tooth-muscle-brain conversations to cease and neuromuscular peaches prevail.
Some Comments Received
James L Sanderson Jr DMD: Before I would think about equilibrating them I would do a sleep test for apnea.
Philip Millstein, DDS: This is a good idea to develop a conversation that can help a clinician. There are few places or people to turn to for advice - few occlusion blogs that speak to immediate and personal needs.