9B. Occlusal Trauma Flashcards
Masseter
• the musculature is right over the ____ teeth
• If you’re squeezing back and have one of those
interferences
◦Just image how much pressure is squeezing on that
tooth
‣ It can cause the tooth to become mobile, sore, you
can get TMJ issues.
posterior
Class 3 lever
• ____ interference is an example of a class 3 lever
◦If the fulcrum is the tmj and the effort is the muscles
◦You can generate ____ pounds of pressure on the molars
◦But on the front teeth, because it’s a longer lever arm, you are only generating ____ pounds of pressure
• *Note I didn’t understand what he was saying here *
◦“This is why the anterior teeth you can slide forwards and ____ the back teeth but it doesn’t damage the front teeth
◦If you did that in the back teeth with all the pressure it’s more damaging
nonworking
250
50
disarticulate
Bruxism Causes
- ____
- malocclusion
- ____ interferences
- ____ disturbance
- emotional stress
- ____ dentition
- psychotropic medications
idiopathic
occlusal
neuromuscular
transitional
Psychotropic Medications Implicated with Bruxism
- Selective serotonin reuptake inhibitors
- Antipsychotics
- Antidepressants
\_\_\_\_ (venlafaxine) Haldol (haloperodol) \_\_\_\_ (fluvoxamine) Prozac (fluoxitine) \_\_\_\_ (sertraline)
effexor
luvox
zoloft
Bite collapse
• bite collapse occurs when one of the basic rules of occlusion has been violated.
◦Mainly the posterior teeth support the occlusion and the anterior teeth disarticulate
◦If there is no ____ teeth and you bite down (next slide)
posterior
Bite collapse
- whether its missing teeth, broken down teeth, or decayed teeth the trauma isn’t here (points to red arrow), its here (points to orange arrow)
- As the jaw over closes the ____ teeth can’t take that much pressure and they start to flair out
- So a bite collapse can cause this trauma to the ____ teeth
anterior
anterior
Bite collapse
• Just restoring that normal marginal ridge anatomy will restore the bite 2-3 mm will kinda give you an idea of how much that bite has collapsed
• To treat this pt properly you would have to restore some kinda ____ support — ideally implants, as well as restore the VDO that was lost by the bite collapse
• Then once you restored that, the anterior teeth may return to a normal position just from ____ alone
◦ But sometimes we’ll use ____ to pull the teeth back in, so they can provide anterior guidance once we have posterior support
posterior
lip pressure
ortho
Bite collapse
• even in a minor bite collapse, like this, there can still be trauma because the teeth are hitting off axis
◦The teeth aren’t being supported the way the oblique fibers of the PDL best support it
• This tooth is being hit off axis every time the pt bites down — its being crushed
• If a pt loses a molar and doesn’t replace it. The tooth behind it moves forward and you often see a pocket right here
• The reasons for this pocket are:
◦You get a little valley that is hard to clean so ____ and
plaque is getting trapped
◦Also the ____ is getting crushed every time the pt
bites down
‣ Its a ____ of destruction
• So look for these ____ where ever you see collapsed teeth, such as this.
food
ligament
cofactors
pockets
Premature contacts and interferences
Early contacts occurring in jaw movement that are stronger or sooner than desired \_\_\_\_ (Fremitus) \_\_\_\_ \_\_\_\_ \_\_\_\_
centric
protrusive
working
non-working
Cusp to fossa
- These two pictures were taken the same day
- As he reduced the ____ the teeth just settled together
- Over the next few weeks the mobility subsided on this tooth
contour
Protrusive interference
• So what’s happening here?
◦You should be able to look at a case like this and say this is a
bruxer
◦The pt was referred to him because of right side myofascial pain and he had tenderness in the muscles.
‣ So it wasn’t a joint problem it was a muscle problem
• What’s causing this?
◦It’s not the bruxism, although that’s part of it
◦What’s happening here (points to red arrow) is the pt was
having a protrusive interference.
◦He had his upper third molar (#16) removed, but not #17 so it
super erupted
◦Now he is trying to grind on his front teeth, but he cant bc the
third molar is ____ with the second molar in the upper
quadrant
◦This is causing the muscles to go into ____
• The treatment of this is to ____ the lower left third molar and a ____ to control the bruxing habbit
interfering
spasm
extract
bite guard
Working interference
• lets look at working interferences
• this patient came to him bc she had a crown placed on #14 that became sore and mobile
◦The referring dentist check the bite and said it wasn’t high, so
he didn’t know what was wrong
◦BUT he didn’t check the tooth as it went into ____ excursion
‣ There was an interference
‣ The buccal cusp on #14 was too long and the K9 no longer
had contact
‣ Is the buccal cusp a support or guiding cusp? (No one
answers)
• What are the supporting cusps?
◦The ____ of the upper and buccal of the lower
• So the buccal of #14 is a ____ — it doesn’t
support the bite, so we can shave that cusp and not change the support for the bite
lateral
palatal
guiding cusp
Working interference
• so we shaved the guiding cusp and we now have contact in the ____ area
◦You don’t want the contact back here (points to the arrow in the posterior)
• Remember the cusps in the fossa are the ____
K9
supporting cusp
Working side interference cross tooth
• This is another working interference, but its not the buccal of the upper its the lingual of the lower
◦So the pt is sliding to the right, this shouldn’t be hitting as the patient goes into this movement
‣ This fossa is too ____
‣ This is a working interference
deep
• this patient has two crowns. What is wrong with these crowns?
◦Student response: “they look large relative to the other teeth”
• What else is wrong? Which cusp should be higher on the lower teeth the buccal or the lingual? (Next slide)
• (comes back to this slide) These are too high
‣ Why are they too high — its the way the lab made them
• Don’t assume the lab knows more about occlusion than you do.
‣ What the lab did was match it to the broken down tooth adjacent to the crowns
READ ME
Curve of wilson (transverse curve)
Curve represented by the cusp tips of molars in the ____ plane
• Think about basic occlusion — the curve of Wilson/ the transverse curve.
◦The ____ cusp of the upper hang down lower than the ____ cusp to give you the normal curve of Wilson
◦goes back to previous slide
frontal plane
palatal
buccal
• Now the pt is moving to the right side.
• The interference is removed and there is guidance on the
____
• these guiding cusp - someone used the rule of ____, the
buccal of the upper, the lingual of the lower
◦This is an easy way to remember which cusps are the
guiding cusps
◦Unless its a cross bite, you should be able to reduce
the guiding cusps without changing the basic support of the bite
‣ If you reduce the supporting cusp too much, you can close the bite and the ____ teeth will start to hit
• Causing these teeth to become loose or separate
canine
bull
anterior
Non-working interference
Prematurture contact on the ____ side preventing guidance on the working side
• non-working interferences are the tough ones
• These occur on the ____ cusps
◦The palatal of the upper and the buccal of the lower
non-working
supporting
Non-working interference
• this pt is moving their jaw to the left
• This is a non working interference — it usually happens in the ____ areas
• This pt has very ____ cusps — that’s what’s interfering
• You can’t just arbitrarily reduce the supporting cusps as I
said before
◦You might end up having the front teeth coming
together too ____
molar
steep
hard
• we have the pt slide to the side to observe the non working interference
◦But this isn’t where the damage occurs
• The damage occurs on the return stroke as the pt
squeezes the teeth together
• As the jaw slides out to the side you are using relatively
____ muscles ( Lat. pterygoid, geniohyoid, digastric)
• The ____ muscles (masseter, temporalis, medial
pterygoid) occur on the return stroke.
weak
strong
Non-Working Interferences Problems
• A major cause of ____ trauma
• Mechanical threat to ____ cusps
• Problem area confuses patient. Chewing on ____ side makes it worse
• ____ makes the problem worse as contacting areas widen
• Occlusal irritant associated with ____
occlusal supporting opposite wear MFP
Non-working interferences
- Usually located on the ____ incline of the lower supporting cusps and ____ incline of the upper supporting cusps.
- Also ____ cusps of upper molars and ____ cusps of lower molars.
- Runs ____ across tooth
- Any alteration in plane of occlusion, increase in cusp height, or transverse curve ____ its potential
- Results from interplay between working,side, nonworking side and condylar elements
mesial inner distal inner mesiolingual disto-buccal diagonally increases
Causes of non-working interferences
First look at the ____ side –is there guidance?
Loss of tooth substance on FOA or guiding incline due to: ____ teeth Caries fracture Wear
Drifting teeth as in ____ bite collapse
____ Deformity
working
missing
posterior
orthodontic
Causes of non-working interferences on working side
• If there is no ____ here, something is going to hit back here
guidance
Orthodontically incorrect relationships
• This is an adult who had crowded ____ incisors - just wanted bottom teeth straightened
◦“You cant but a quart in a pint bottle”
◦If you spread these teeth out you are going to loose ____,
which is what happened here.
• So orthodontic errors can cause loss of guidance
lower
guidance
Causes of Non-Working Interferences On the
NON- Working Side
• Tooth loss-____
tilting and extrusion
Shifting and Interferences Caused by Overcarved Restorations
• Dentist can cause interferences by ____ restorations
• If its too deep the cusps will ____ in together
◦There is no freedom for the patient to move side to side leading to trauma of the tooth
over carving
lock
Overcarved restoration
causing ____
shifting and interferences
Non-working interference
• If the cups are too ____ you cant slide out
• To correct this you would shorten the cusp and fill the
fossa in
steep
OCCLUSAL THERAPY
Occlusal Adjustment : ____
Appliance therapy: ____
Orthodontics
Restorative Treatment
limited and complete
bite plate, occlusal guards
Limited occlusal adjustment
\_\_\_\_ Pre-restorative \_\_\_\_ or Periodontal pain or infection Localized Occlusal trauma \_\_\_\_ causing TMJ or MFP Reduce risk of fracture
• If you are doing any restoration you should check the opposing tooth to make sure the cusp isn’t too long or if its even
◦Adjust it before you do the restoration
• If you take one thing out of this lecture its what I’m going to talk
about with endodontic or periodontal pain or infection
◦Tooth infections hurt (thanks)
◦If you bite down and you have a PA lesions — it hurts
‣ There is no antibiotic or pain reliever that works faster than getting that tooth out of ____
• Teeth that are painful you have to ____ the occlusion
esthetic endodontic interference occlusion reduce
Reduce risk of fracture
- limited bite adjustment
- This tooth is already fractured and needs a crown
- Until the crown can be made we need to ____ it further to prevent more damage from being done
reduce
Pre-restorative adjustment
Fossa filling
• This is what he was talking about earlier
◦ Points to picture 2
‣ If you have a ____ interference, which occurs b/w the supporting cusps and you also have a restoration to do you want to reduce the height of the ____ cusp (points to picture 3) and build the ____ up
• This is called fossa filling
◦the ____ you can make the cusps the less chance there will be interferences
non-working
support
fossa
shallower
Complete OA for multiple interferences
• if you have multiple non working interference you may have to get into a ____ occlusal adjustment
◦Which is beyond the scope of what we are learning today
complete
Retruded path of mandible
Any Major Occlusal Change should be Done in ____
• Any changes you are doing major changes to a pt bite you work from CR
◦If you don’t have landmarks when the patient comes together you don’t know if they are bitting a little left or a little right
‣ You can’t use the teeth, you need to use the ____ position
• Whenever we are doing any extensive work with the bite we are always going to work from ____
centric relation
jaw
centric relation
Complete occlusal adjustment
• Guide the patient back so the condyle is fully seated into the ____
• Most patients have a difference between there ____ position
and their retruded contacting position
◦This difference can be used as a tool to open the bite and give us room to adjust these cusps
fossa
intercuspal
Bite opening in retruded contact
• when you put the pt back in retruded closure you’re going to get a little bit of opening in the ____ part of the mouth
◦We can use this to ____ the supporting cusps that are too long so the pt doesn’t have the interference
front
shorten
Buccal-lingual relationship in RC
• as the jaw moves back you are moving a narrower part of the mandible into a wider portion of the ____
◦This creates a buccal-lingual discrepancy
maxilla
Complete occlusal adjusment
• you account for the discrepancy by shaping each ____ to fit back in, but its going to end up shorter
cusp
Occlusal contacts in retruded closure
• This is what you don’t want to see
◦You don’t want to see marks on cuspal inclines
‣ They need to be on ____, marginal ridges and fossa
cusp tips
Occlusal adjustment to centric relation
• we have to move the mandibular buccal cusps ____ so it sits in the fossa of the opposing tooth
mesial and buccal
Correction of non-working interference
• Using the Retruded contact to reset the bite is called the ____
• What it means is as you move the jaw back, you are hitting on the ____
• You can then shave the cusp tip so it comes back into the fossa, but the cusp will be shorter than when it started
◦This ____ the chance of interference when the pt goes into lateral movements
x factor
inclines
lowers
• this pt had a progressive open bite and then developed a ____ to fill the space
- He was able to create sound occlusion just by doing the adjustment
- You have to do this like you’re doing a denture with the jaw in ____
tongue thrust
CR
Complete Adjustment Guidelines
• Work from ____ if possible
• Don’t start it unless you can ____ it or patient will be left without a stable intercuspal position
• Avoid ____ fossae, shallow cuspal inclines of opposite arch instead
• Work toward concepts of the ____ (even marginal ridges etc)
• Look, Feel, Listen
centric relation
complete
deepening
ideal occlusion
Complete Adjustment Guidelines
• Adjust to stable ____ first, then check for interferences
• Beware of the ____ occlusion (no inclines to reduce)
• Beware thin ____ and sensitive teeth
• Beware the large ____
• Amount of adjustment should relate to degree of problem
intercuspal position
worn
enamel
slip
Not treatable w OA alone
• If you have a V shaped arch and put the jaw into CR, you might get a very large ____ discrepancy
◦You may not be able to do a bite adjustment without orthodontically tipping the ____ teeth
buccal-lingual
posterior maxillary
Other Means of Correcting Interferences
____ Treatment
____
restorative
orthodontics
Correction Of Non-Working Interferences
Providing more guidance on the ____ side
working
• Pt didn’t have any guidance so he bonded ____ retainers to give guidance
lingual
Canine bicuspidization
• But these teeth are function
◦Turns the canine into ____ and the laterals
have platforms
biscuspids
IMPLANTS vs NATURAL TEETH
IMPLANTS ARE ____ TO BONE
TEETH HAVE A ____
ankylosed
periodontal ligament
OVERLOADED TEETH RESULT IN ____ LIGAMENT SPACES, ____ AND MOBILTY
widened
migration
TEETH MIGRATE, DEPRESS, ERUPT, DRIFT, AND ALIGN TO THE OCCLUSION
____ DO NOT
implants
Overloaded ____ may fracture, loose Integration, or show marginal bone loss
Overloaded ____ components may fail
____ can break or loosen
implants
restorative
screws
• He made a lot of mistakes
◦He would not put the implant in at the same angle — right away the forces are going to hit off axis
‣ Instead he would lift the sinus do a ____ and place the implant in straight
◦Mistake two is that you shouldn’t attach implants to teeth because they have some ____ to them
• Implants with ____ loss due to bridge attached to a natural tooth
bone graft
movement
bone
Provisionals
Our best tool for determining any bite problems is in the ____
• work out of the problems
◦Make sure there are no interference, fremitus, there is proper guidances
provisional
Appliances
Hawley bite plate
we can tell we are in Cr by the ____ that is made on the bite plate when the patient is doing excursive movements
V
Bite plate
This causes the teeth to only hit in the front and allows the ____ teeth to erupt
• if you have multiple ____ teeth in a perio cause he
often puts in a bite plate to allow things to tighten up a bit
◦This also allows the teeth to ____ so he can adjust the occlusion to how he wants it
posterior
mobile
erupt
BITE PLATE Occlusal rest in trauma case \_\_\_\_ muscles to locate CR Recapture displaced disk Evaluate \_\_\_\_ dimension Provide posterior eruption to correct occlusion modify vertical periodontal defects Disarticulate for \_\_\_\_ correction Tooth movement or retraction
relax
vertical
cross-bite
• this is what we call ____ dentistry — if you have a hole you fill it in. You don’t correct the whole problem
This is a complete collapse
There’s no room for teeth ____ because the bite has collapsed
conformity
posterior
• the first thing that was done was the ____ teeth were splinted and bonded together
Then ____ is fabricated
• it has a wide platform because the teeth have flared so much
• We use this to establish the ____
• We can check lip support and see what the face looks like
• What we start to do is bring these max anterior teeth back in
◦ There is very little anchorage so we have to do this one tooth at a time
lower
bite plate
VDO
• here are the ____ we had before due to the protrusive and lateral movements
◦The blue spots are CR that’s how far back they can go
◦The red is when you make the movements
We use the ____ springs to bring the teeth back into position
We even out the ____ teeth so there is room for crowns
Vs
finger
posterior
• This bite platform prevents the bite from ____ again
collapsing
Bite guards
There must be ____ contact throughout. Every tooth must have a contact
When they go into excursive movements it’s don’t just the same as the natural dentition
even
Properly adjusted bite guard
• This is what is should look like
◦ Points of contact in the ____ but no slides
posterior
Occlusal Trauma Summary
- ____ trauma can cause damage to the teeth, periodontium, and TMJ complex
- Occlusal trauma does not cause gingival ____
- Occlusal trauma does not affect the ____ because the gingival tissues move freely with the tooth.
- Occlusal trauma can damage the deeper periodontal tissues, i.e. the ____
occlusal
inflammation
gingiva
attachment apparatus
- Occlusal Trauma can be a co-factor in ____ and thus increase the rate of destruction
- Occlusal trauma can ____ to the pattern of vertical bone loss
- Mobility may ____ after periodontal treatment. However some degree of mobility is acceptable as long as the mobility is not progressive and teeth are maintained in health, function and comfort.
periodontitis
contribute
remain
- If tooth mobility continues to increase after treatment further occlusal therapy or ____ would be indicated
- It is incumbent upon us to thoroughly understand the principles of occlusion and to apply them our treatment. Thus we can prevent or treat pathologic occlusion and the resulting occlusal trauma
splinting
