1 occlusal splints

8/11/2019 1 Occlusal Splints

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cortical bone (2) which makes it the ideal stable and load-bearing area. ( see figure

1 )

So when were relaxed (not chewing or doing any function with the mouth) the

mandible relaxes, but the muscles will pull the mandible in order to reach the MSposition of the mandible .

Now what happens when we close our mouth (as when were eating), the mouth

will close and the occlusion for a brief time would be cusp to cusp, now cusp to

cusp is not an occlussally stable position but rather considered as an occlussal

interference, so here the body is not looking for the Muco-Skeletal position

anymore, but rather it is looking for the most stable occlussal position to solve the

problem of the interference that occurred upon closure of the mouth .

In order for the body to solve this interference and achieve maximum intercusption

(MCP/ICP ) ( occlussal stable position during function ) and change the position

to cusp to groovewhich is occlusally far more stable than cusp to cusp. The

muscles will contract ( especially the lateral pyerydoid muscle ) with this action of

the muscles the mandible will move a little forwardand thus achieving cusp to

groove or the MCP/ICP .

Now what happens when were eating (functioning) , while we chew we dont eat

in the CR but rather we function around the ICP ; meaning that at the end of the

mastictory cycle a brief contact between cusps would happen ( this brief contact is

essential to incise food ) meaning that we dont function exactly at the ICP because

we dont eat food by opening and closure but rather by doing lateral movements ,

so were functioning AROUND ICP .

Now the above senieros hold true for 90% of the population, meaning that 90% of

us will have occlussal interference upon closure and their mandible will move

forward a little bit to accommodate and solve those interference by going cusp to

grove ( ICP /MCP ) , the other 10% have different screnrieros ; theyre always on


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their MS position because they dont have occlussal interferences and thus the

body didnt feel the needto change positions and move the mandible a little

forward; meaning that their ICP is the same as their CR .

Now a question rises , the joint position in 90% of us while closing and chewing is

not in its orthopedically stable position ( the MS ) , why didnt we develop any

problems in the TMJs ? here, the condyles new position that the body made which

is a little bit forward is still compatible with the health , unless there are unusual

movements or loading thats happening in the joint ( e.g. burixisim , clenching )

Theres a concept called Mutually Protected Occlusion, in simple words this

concept means that: anterior teeth protect the posterior during protrusion and

posterior teeth protect the anterior teeth during mouth closure in maximum inter-

cusption .

The anteriors will prevent the premature contact of the postieror teeth during

protrusioin and thus protecting them , and the posteriors are more vertically placed

and have more roots thus the force applied to them would be more than the anterior

and thus theyll protect the anteriors; theyll withstand more force than the

anteriors.

Any interference that disturbs this mutually protected occlusion will lead to tliting

and occlusion interference during function and protrusive movements, thats why

most restorations and prosthesis (crowns and bridges ) are made to conform to

patients existing ICP , meaning that we must have the maximum number ofcontacts( every tooth wither its sound or restored must have an opposing

contact on the other arch) in order to preserve this mutually protected occlusion.

Consider the following examples:


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-

A dentist might be presented with single high crown prosthesis; hell suggest

that trimming this high crown will resolve the case. But what will actually

happen is that supra-eruption of the opposing teeth in the other arch will

occur. (So the mutually protected occlusion concept is damaged, here when

the patient would protruded hell have occlussal interference at theback) thismight lead to either breakage of the crown or in the most severe cases TMJ

problems.

-

A dentist who had just finished doing a restoration, he didnt check to see if

its high in occlusion (high spot) or not. Now whenever the patient is

chewing on that side the

muscle will contract to

prevent him from hitting

that spot every time, at thelong run the muscles will

be tired and TMJ

problems will occur (again

the mutually protected

occlusion is damaged).

In the above two examples you now realize how

important is to maintain this mutually protectedbalance, and now you realize why we love to have

maximum number of contacts on each and every

tooth, thats why most restorations and prosthesis

(crowns and bridges ) are made to conform to

patients existing ICP . for this to be an appropriate

form of treatment ICP must be stable and occlussal

anatomy of all restorations must be carefully

shaped to reproduce correct contacts; meaning thatwe must have the maximum number of contacts

(everyrestorations or prosthesis must not

damage the mutually protected occlusion , or in

other words , a restoration or a prosthesis in the

back must not interfere upon protrusion and a


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prosthesis or restoration in the front must not also interfere upon closure ) .

(see figure 2 : A: a contact in the back prevented lead to less stable postion in the

articular and thus TMJ problems , B : good crowns/restorations show no

interference and thus good position in the articular was achieved and no problems

were found )

The question that rises now is how do we manage those patients who have

interferences? Or how do we restore the mutually protected occlusion? The answer

is we give them occlussal splint, consider figure 3 and 4 , in 3 notice how a faulty

crown is damaging the mutually protracted occlusion and that the lateral pyerydoid

muscle is always contracting and notice in 4 how we added an occlussal splint or

an antieror guidance that relaxed the hyperactive muscle.

After weve covered the basic concepts of occlusion physiology and mutuallyprotected occlusion, and after weve understood the need behind occlussal splints

well talk about them for the rest of this lecture.

The definition of the occlussal splints is: Any removable artificial occlussal

surface used for diagnosisor therapyaffecting the relationship of the mandible tothe maxillae. It may be used for occlussal stabil ization, for treatment of

temporomandibular disorders, or to prevent wearof the dentition GPT-8

Okoson defined it as follows: it is a removable device usually made of hard

acrylic , that fits over the occlussal and incisal surfaces of the teeth in one arch ,creating precise occlussal contact with the teeth of the opposing arch .

So, the occlussal splints devices can be used to either stabilize the occlusion, treat

TMJ problems or aid in diagnosis.

But how exactly can we achieve a diagnosis with occlussal splints? Consider the

following example, you made a new bridge work for your patient and inserted into

his mouth, couple of weeks later the patient is complaining of a pain in his jaws,

youre suspecting that a high spot in your bridge is that cause of this but still you


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need to confirm that. What youre going to do is that youre going to make him an

occlussal splint (a night guard) and ask him to use it, the patient reported back that

hes now happy and no pain is found, so you concluded that the high spot on that

bridge work was the cause, so here the occlussal splint was used as a diagnostic

tool.

Occlussal splints can have many different names like (refer to the slides to have the

full list ) :

anteiror reprogramming splint

anterior postioning splint

annterio repostioing splint

flat occlusal splint

bite splint mandibular advancement device

muscle deprogramming splint

occlusal protecting splint

Lucia Gig

Orthopedic deprogramming device

Occlussal correcting splint

Distal push splint

Buccal separator

discluding splint

Its indicated in the following cases :

Temporomandibular disorders ( first line of treatment )

Myofascial pain

Disc displacement disorders

Arthritides of the TMJ

Headache/migrane


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Sleep burxism

Sleep apnea

Parckinsons disease

Oral tardive dyskinesia

Its applications are as follow:

Occlussal rehabilitation :

o Ortothodontics

o

Periodontics

o

Prosthodontics

Establishemnt of CR (where we cant determine CR )

Protection of new restorations ( like in the case of vnerees and

all ceramic restorations )

Creating space for restorations

o

Phantom bite ( where the patient cant determine a bite ) .

o

Others :

Diurnal burixism

Sports

Cheek/ fingernail biting

Electroconvulsive therapy

Lip commissure burn Esophageal reflux

Sinusitis

Diagnosis of possible cause of TMD

Splints are indicated to reduce harmful effects :

o

Teeth : attrition , fractures and mobility or pain

o

TMJ : pain , traumatic arthritis , degenerative remodeling

o Muscles : pain or spasm


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Note that splints can not cure bruxism because it is a centrally mediated disorder .

Howevere it can reduce its effects through :

Providing a softer surface to wear ( its hard acrylic and it wont wear teeth )

Redistribute the tramtic forces over larger number of teeth Splinting teeth together and provide ideal occlussal contacts.

Occlusal Splintscan be classified according to :

1-

Material of construction: Hard

Soft

Bilaminar

2- Coverage:

They could be full coverage or partial coverage

3-

Function: Stabilization

Repositioning

4-

Position:

They could be maxillary

or mandibular


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1-

Hard acryli cis the most common usedmaterial, which is:

1- chemically cured or heat/pressure

processed

2-

hard on both occlusal and fitting surface

3-

Durable

4- Easy to repair

5-

More retentive6- Less prone to change in color & plaque

accumulation.

2-

Soft or resilient plastic night guard:

Giving a patient with tempomandibular disfunction (TMD) a soft night guard is

just like giving him/her a chewing gum and ask him to chew it!! Thus; instead of

making the muscles relaxed you're making the condition worse !

So ,what is the use of soft night guard ?!

They're just used in emergency cases, if someone has acute pain and you want

something to open his bite to relax the muscles , you should give him soft night

guard for few days then make him a full hard night guard .. JUST in Emergency

cases

3-

Bilaminar ( dual laminated) :

- The side toward the teeth is soft ,and the one toward the occlusal side is

hard .

- Can maintain a stable occlusion

Other properties mentioned in the

slides:

Vacumformed vinyl splint

Soft on both surfaces

Not durable

Cannot maintain stable occlusion

Helpful in emergencies but might

lead to increased muscle activity


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Partial coverage :1- Anterior bite plane

2-

Posterior bite plane.

Anything you wear for more then 4-6 weeks with

partial coverage will lead to irreversible changes in

the occlusion,that's why full coverage is

preferable.

If a patient uses a posterior bite plane and wear it continuously for 4-6 weeks

,there will be supra eruption for anterior teeth ,and ends up with posterior openbite.

And the same with anterior bite plane where you will end up with anterior openbite

within 4-6 weeks.

These are types of irreversible damage, thatswhy

we hate partial coverage splint !!

Other examples of partial coverage splints include

1-

Lucia Gig

2-

Nociceptive Trigeminal Inhibition Tensin

Supression System (NTI).

3- The Anterior Medline Point Stop (AMPS)

devices.

If you used them you have to strictly tell

the patients not to wear them continuously,

otherwise well have supra-eruption andend up with an openbite .

Lucia Gig


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Could be maxillary or mandibular.

1- Maxillary appliances :

have more coverageless likely to break

more stable

better retention

More versatile

2- Mandibluar appliance :

are used for class III occlusion &posterior crossbite they have minimal show on the patient

easier to speak with

The splint therapy is effective in reducing the pain in 70-90 % of the TMDpatients, although they do work their true mechanism of action is still not known,

there are some proposed theoriesconcerning their mechanism of action:

The table below summarizes these theories :

Dental reasons for efficacy Nondental reasons for efficacy

Alteration of the occlusal condition Cognitive awareness

Alteration of the condylar position Placebo effect

Increase in the vertical dimension ofocclusion

Increased peripheral input to the centralnervous system decreases motor activity

Regression to the mean(natural

fluctuation of symptoms)


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- The most convincing one is cognitive awareness (nondental),when you give

a patient a night guard you remind him not to chew , to reduce bruxism .

-

Placebo effect ,whenever you put anything between his teeth he feels that youcare for him this why he will feel better , theres a dentist who did a research

on three different groups . The first one had a real night guard that the sample

wore for 2 hrs , the second sample had a fake one where the night guard only

covered the palatal surface and the last sample didnt recive and night guards

but instead they were treat with a compasinte and a caring way via the dentist .

Surprisingly all the three groups showed decreased TMD symptoms.

-

Increased peripheral input to the central nervous system so decrease motor

activity

-

regression to the mean (natural fluctuation of symptoms) : Which means that if

a person has a stressful life event in a specific period of time he will suffer

from TMJ problems ,but when this stress goes away his condition will be

resolved and the TMJ will come back to the natural relaxed state.

1-

Stable with no rocking

2- Ease of placement

3- Smooth with no sharp edges

4-

Reasonable esthetics

5-

The contact should be

-

Balanced in the centric relation; every single tooth has to have

centric stop. when you put the night guard in the patient mouth let

him bite and put a horseshoe articulating paper , every single tooth in

the lower should have a mark on its occlusal surface, if there are

marks on the posterior teeth but nothing on the anterior; supra

eruption of the anterior will result .If there is anterior contact without


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posterior contact supraeruption of the posterior will happen. If all

teeth have a contact except one tooth ,this tooth will supraerupt alone

and you will notice in those patients with night guard when they

wake up in the morning they will said that they bite on one tooth

,why ? due to supra eruption.

- Occlusal surface should be flat

-

Immediate posterior disclusion on protrusion and lateral excrusion

- 0.5 mm freedom in centric

1-

Take a full upper and lower alginate impression all teeth should be

recorded.

2-

Bite registration on RCP preferably with facebow record ,take precentric

occlusal registration.

Upper and lower teeth should not touch when I take the bite ,, there

should be 2 mm separation posteriorly and about 3-4 mm separation

between the incisors anteriorly.

3-

Mounting the casts using facebow record and the bite provided.

4-

After the mounting do block out (very important )

If you do block out before mounting you can't mount the cast because the

cast will not stick to the bite .

Mount firstthen block out

Where you should put the plaster ?

- in pits and fissures,

-

the embrasure area in the lingual side and cover the lingual gingivalmargins.

-

do not block out labial undercuts because you will use the labial

undercuts for the retention of your appliance .


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-

Draw a line to determine the extent of the splint ,4-6 mm of the palatal

gingival margins ,2-3 mm from the labial surface of teeth.

5-

Then do wax up using two layers of wax ,adapt them on the surface ,this will

produce indentations which you have to remove them later ,you just need a

flat surface.6- Use an articulating paper to produce dots on all the occlussal surfaces there

must be marks ( contacts ) the dots showed be :

a.

All teeth must showcontacts in ICP

b. Only the caninescontacts in lateral extrusions

c. Anterior guidance componentshowed be only on the canines (

preferable ) or canines and lower incisors

7- Add wax labial and mesial to lower canines to establish a Canine ramp or

just on one canine ,every doctor has his own way and both are correct8-

Then do flasking

9-

Packing in heat cured acrylic

Inspect the appliance for sharp margins

Check for sever undercuts.

Carefully place the appliance in the mouth and don't forceit into place anddon't allow the patient to insert it at this stage.

The splint should have a light comfortable pressure with a soft click.

Make sure that it's fully seated before you start adjusting the occlusion.

If the appliance is not stable or rocking or not retentive

-

check for undercuts

- consider relining

- consider remaking

Use an articulating paper to check for occlusion ,first establish even contacton all teeth at RCP,then check for canine guidance on lateral excursions and

protrusion, if you do the opposite it won't work .

Always check RCP first.


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give post operative instructions , the splint should be worn as recommendedby the dentist.

saliva flow will increase in the first two weeks ,which is normal of artificial

appliance.

It's normal to feel tightness for the first 2 minutes of wearing.

If it's not worn keep it in water (very important)

Regular check up is mandatory

Do Not wear the splint for more than 4-6 months without review

Brush the appliance with soap after meals

Dont bite or clench continuously on the appliance ,it's there to make you

relax

Review after 7 days to recheck the occlusal contacts.

Remember that if the patient is suffering from TMD it will be difficult to

establish centric relation record correctly from the first appointment so you

have to repeat it again .the patients will have pain on the first appointment

and their muscles are contracted so the RCP won't be correct at the

beginning ,so what to do ?

First fabricate the splint on RCP, then after one week if the muscles

improved the mandible will get backward a little bit, then test it another

time, till the signs and symptoms of muscular tenderness goes away .

If I want to use the position of the mandible for restorative purposes ,the

occlusion shouldnt be changed for at least two consecutive appointments

before I can go ahead.

1 occlusal splints

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