(2) Col Occlusion

7/30/2019 (2) Col Occlusion

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If all is achievedtreatments is successful and compete

Principles of Occlusion in Restorative Dentistry

Concept of Complete Dentistry:

The ultimate goal is to achieve a maintainable health of the whole masticatory system.

|Definition of Occlusion|

In Dictionary, it is defined as the act of closure.

In Dentistry, it is defined as the contact relationship between teeth. It comprises also the multi-factorial functional relations

between teeth and other components of the masticatory system (Teeth, investing structures, Jaws, TMJ, and Muscles of

mastication).

Important Guidelines:

- All parts of the masticatory system act in harmony and what affects one part will

eventually affect all other parts of the masticatory system.

Examples:

Carious tooth or premature contactaffects the whole masticatory system. Bruxism causes excessive wear of teeth. Mobility due to alveolar bone resorptiondecreases functional performance

of mastication.

- Dental problems are progressive and Deterioration of the whole system will eventually occur if problems are left untreatedin a reasonable time frame

- Careful diagnosis is necessary by complete examination of the masticatory system to identify the causes and the effects ofany disharmony and to establish definitive goals and assess the prognosis of any required interference by treatment since

the ultimate objective is optimum oral health of the patient

Four Comprehensive Goals for Complete Dentistry

Optimum oral health of the entire gnathostomatic system. Anatomic and form harmony. Functional harmony. Occlusal stability.

Basic principles for applying the concept of Complete Dentistry

- It is a concept for both diagnosis and management of occlusal problems- Understanding the reasons for form & its relation to functions of teeth provides a link of cause-effect relationship.(Keep in mind that health of dentition is dependent on suchform &function and that a disease will occur if disturbed)

- Interference for correction of dentition should be limited to conditions where there is no harmony of form & function andshould be directed towards why we correct rather than how.

- Keep in mind that treatment of the effect without correcting the cause is rarely successful.

Anterior Open bite caused by tongue thrusting Group of function occlusion Canine protected


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Application of basic goals of complete dentistry in diagnosis & treatment of occlusion problems

Optimum Oral Health It is required to obtain highest functional performance of dentition

- Deterioration of oral health requires thorough diagnosis & treatment planning to achieve 2 major objectives:

1. Finding the causes of deterioration.

2. Determining the best method to eliminate each cause of deterioration.

- Degree of success of treatment depends on the degree of elimination of causes of deterioration. (Keep in mind that Total

Elimination is not always possible)

|Considerations|

Causes of deterioration usually come multiple. The same causative insult can produce variety of responses in different individuals due to:

- Difference in host resistance

- Different intensity of insult

- Different duration of insult

Similar symptoms may result from completely different causes. Symptomatic relief without identifying the cause isconsidered an insufficient poor type therapy.

Confusion about the cause effect relationship is mostly due to failure to distinguish between Causative factors &Contributing factors

Contributing factors

Does not by itself cause disease, but it either lowers resistance of the host to a causative factor or increases intensity of function or

stress.

The treatment plan should be directed primarily therapy to remove the direct causative factor while increasing host resistance &

decreasing intensity of stress should be the adjunctive therapy.

|Example|

High crown with cusp inclines interfering in lower molar

This insult may cause different responses depending on:

Intensity and duration of insult. Host resistance. Degree of stress of pt during sleep. Presence of periodontal problems. Presence of articular or muscular problems.

Accordingly, 15 conditions may occur:

1. Tooth may become sensitive to hot or cold.2. Tooth may become tender to touch.3. Tooth may become loose.4. Tooth may become worn out.5. Other teeth may wear since the mandible may deviate to positions looking for

a bite of comfort.

6. This deviation may cause other teeth to become loose.7. Deviated jaw may cause muscles to become hyperactive or spastic.8. Muscular trismus may occur due to spastic muscles.9. Headache may result from muscular spasm.10. Combination of sore teeth, muscular spasm and pain may cause tension and stress.11. Tension and pt stress may drive him to depression.12. The combination of mandible deviation and spastic muscles may cause condyle disk derangement.13. The combination of tension and stress with disk derangement may cause degenerative changes in TMJ.14. All of the above may occur.15. None of the above may happen in case of very relaxed pt or a mouth breather.


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Diagnosis & Treatment planning to achieve optimum oral health

Careful diagnosis and analysis is required to observe the effects of disharmony, instability and to find out its

causes. (Keep in mind that an effect should have causative factor/s)

1. Analyze and find out all possible causative factors.2. Analyze host resistance and evaluate any other possible contributing factor.3. Evaluate all effects of the causative factor/s and detect if the effect/s is/are related to intensity &

time of the insult or to host resistance. Also detect if the insult is still active.

4. If the cause is still active, detect the possible methods to eliminate or neutralize its effect5. Select the best possible treatment approach

Utilize recent diagnosis methods (T Scan)

Computerized occlusal analysis, simulation and registration.

(William Maness, Tufts University, 1988), A dream comes true since it allows the study of occlusion for applications in: Restorative

dentistry, Prosthetic dentistry, Implantology and orthodontics.

- It provides quantitative and qualitative analysis of occlusion. The articulating carbon paper provides only quantitative.- It is composed of an automated silver sensor 60 microns in thickness. It is disposable and inexpensive.- It is painted from both surfaces with conductive ink to constitute more than 1500 sensing points.- The patient bites on the sensor which delivers data of occlusion to the computer monitor in terms of (2 dimensional) or (3

dimensional) location of the contact.

- It also delivers the timing of each position contact together with the force at a specific site.- The computer shows a movie on the monitor to simulate patient occlusion and it can be adjusted to display the movie frame by

frame.

Advantages of the T-Scan system over carbon papers

1. Simple and fast procedure. (one minute)2. Dynamic viewing of a movie representing status of occlusion3. Play back or frame by frame analysis4.

Actual timing and force of occlusal contacts represented

5. Provide hard copy of occlusal force/contact relation6. Documentation of occlusal analysis by saving the file enables monitoring of the condition7. Precise , early detection of occlusal disease saves time and reduces return visits8. Early detection of high risk pt and elimination of trial and error findings with carbon papers.Carbon papers

- Take long time to analyze occlusion (20 minutes)- Leave ink marks on teeth which requires an experienced operator to analyze it- Some marks represent contacts while others represent smudge marks


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Finding the causative factors

- Loss of tooth or part of a tooth is usually caused by breakdown of hard tooth tissue or breakdown of its supporting tissues which

could be resorted to: (If the cause or insult is constant, the variation in effect is due to the contributing factor of host resistance)

Causative factors

Microorganisms Stress

i.e.: Caries. i.e.: Wear and tear.

- Bacteria are present in plaque.

- The bacteria and its metabolites cause either caries or

periodontal disease.- The effect is variable from individual to another and even in

the same individual from time to time or from tooth to another

tooth especially when it is combined with increased stress.

- Moreover, absence of stress doesnt mean necessarily absence

of periodontal disease since severe periodontal disease can

occur in a case of occlusal perfection. This clarifies the

importance of the effect of plaque as a causative factor.

- Controlling the causative factors should comprise both

plaque control and occlusal therapy and a time lapse for the

control to achieve the results of therapy.

- Increase magnitude or unfavorable direction of stress can result

in:

1. Hyper mobility of teeth.2. Excessive wear.3. Hypersensitivity.4. Masticatory muscle problems.5. TMJ disorders.6. Periodontal breakdown.7. Development of abnormal chewing habits.8. Fracture of cusp or tooth splitting.

- Control of stress by occlusal adjustment and correct alignment of teeth is very important to achieve the major goal which isreduction of stress on teeth during various movements of the mandible (i.e. elimination of occlusal interferences duringmandibular functional movements). The functional movements are determined by:

1. The anatomic limits of movement: articulating surfaces of TMJ and ligament capacity.2. The physiologic action of the muscles as they move the mandible up to the limits of muscular action.

- Any interference of teeth during either articular or muscular limits should be corrected, otherwise, deterimental stresses arise.- The muscular activity may also be limited by occlusal interference since it will move the mandible only to make the teeth fit in

occlusion by displacing it.


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Two shortcomings arise in Diagnosis to achieve optimum oral health:

First Outcome Second outcome

Failure to understand how little time it takes to

throw the masticatory system out of balance.Conflict about what constitutes the correct position and alignment of the

condyle disk assembly.

- In case of occlusal interference, one or more points at the tooth surface interferes with the physiologic functional pattern of the

condyle disk assembly stress proprioceptive sensors around the tooth will send afferent impulses to brain to come back with

efferent impulses to muscles to move the mandible to a convenient position to brace the condyles on the slopes of eminences to

slightly open the mouth and relieve the stress.

This limiting action of the muscle to embrace the condyles acts instead of the limiting action of the bone and ligament.

- Although the bone and ligament do not feel fatigue, the muscular action will make the muscle feel fatigued with symptoms of

spasm, stretch reflex contraction of the antagonistic muscle on the other side with spasm of musculature of whole neck and

shoulder, pain, earache & headache.

(A high percentage of patients with headache is simply because of minute occlusal interference)


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Relation between Stress due to occlusal Trauma and periodontal status of the tooth

- Despite the extreme mobility patterns caused by traumatogenic occlusion, no evidence that occlusal Trauma can cause anincrease in pocket depth unless there is local factors and gingival inflammation . (If no

inflammation or loss of osseous walls, a severely mobile tooth will be rendered firm by

correcting its occlusion).

- Lindhe J & Nyman S IN 1972 concluded that occlusal Trauma even of the jiggling type in atooth with reduced periodontal support will not cause deterioration of support ifplaque

control and pocket cleaning methods are performed.

- The combination of plaque induced Periodontitis and occlusal Trauma causes progressiveloss of periodontal support compared to teeth without occlusal trauma.

|VIP|

The reason why teeth in hyper function become loose is due to pressure which causes hemorrhage

and thrombosis and destruction of collagen fiber attachment. Excessive pressure renders the

fibroblasts into Osteoclasts causing bone resorption proportional to the intensity and direction of

the applied pressure. In other words, the resorption pattern in case of occlusal trauma is different

from that caused by periodontal inflammation.

- If the occlusion is corrected before periodontal inflammation the loose tooth due tostress resorption pattern will be rendered firm and osteoblastic activity dominates.

- If correction is delayed resorption pattern will change to an inflammatory pattern and major periodontal treatment will berequired together with occlusal Correction.

- If correction is Too long delayed Poor prognosis.- Both correction of occlusal and periodontal treatment are essential to produce optimum maintainable oral health.

How stress affects the teeth

- During normal physiologic function, tooth enamel withstands the ordinary wear.- There is normally an energy conservation system for the masticatory muscles when there is no bolus of food. This prevents

wear and tear of teeth.

- When a bolus offood is presentbetween the teeth, the pressure sensors around the roots of tooth send impulses to make themuscles contract to move the mandible.

- In case of interference, the pressure sensors around the root of the prematurely contacted tooth misinterpret the pressure as abolus and thus activate muscles to contract producing excessive force against the tooth causing accelerated wear and tear of

teeth.- Whenever there is an occlusal discrepancy and the inter-cuspation isnt in harmony with the physiologic function of TMJ andmovements of the mandible, this will lead to:

In the teeth In Masticatory apparatus

- Excessive wear of dentition.- Hyper mobility of teeth due to bone resorption.- Adaptive realignment of teeth.- Tooth sensitivity.

- Muscular spasm.- Abnormal jaw movements.- Condylar embracement.- TMJ pain, Earache & headache.

Anatomic and Form harmony (Anatomic and form harmony and alignment of):

- Teeth- Muscles of mastication & musculature of lips, cheeks and

tongue

- Temporomandibular articulationEach tooth form is designed for certain functions

Improper form or misalignment of teeth drives the masticatory

system to adaptation. Adaptation creates stresses & enhances

wear.

Normally,

Incisors receive (35-50 psi), Canine (47-100 psi), premolar (80-150psi) & molar (127-250 psi)

Incorrect alignment creates detrimental stresses in magnitude and direction


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Muscles of mastication: Temporalis, Masseter, Median and lateral Pterigoids

- Each muscle has an optimum length of contraction and anotheroptimum for rest.

- Unbalanced occlusion puts the muscle in a state of continuousdemand.

- Correct anatomic harmony of teeth, proper alignment and optimummuscular activity allow the muscle to function

to its normal limits without interference.

Lip and cheek musculature affects alignment and may cause disharmony of esthetics and function

|Facts|

The Purpose of a Joint is to allow two or More Bones to move in Relation to Each Other.

The Purpose of Ligaments is to Limit the Movement of a Joint within the functional range of muscles , therefore, joints Funct ion

within the Limits of the Ligaments.

TMJ articulation should possess correct relations and act in harmony

with teeth contacts during functional movements and with the

functional limits of mandibular movements by the muscular action.

This anatomic and form harmony predisposes to functional harmony.


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Functional Harmony

- Each part of the masticatory apparatus has certain functions and share with other parts to perform certain functions:- E.g. Teeth main function is mastication but it shares in speech.- Functions of masticatory system include: (Drinking, Swallowing, Sucking, Breathing, Smiling, Kissing, Licking, Spitting, and

Speech.)

- All parts of the masticatory system like lips, tongue, cheeks, bone, joints & muscles have highly organized relationship to eachother and to the teeth during functions.

- Functional disharmony means disturbance of this organized relationship.- For proper management we should not only deal with manifestations of disharmony but we need to recognize and treat the

cause to avoid undue or insufficient treatment or relapse. Functional disharmony usually causes a chain reaction in themasticatory system that affects all elements and ends in more dysfunction and disharmony.

|E.g.|

Patient with enlarged adenoids finds difficulty in breathing open mouth and tongue thrust to give airwaypressure of tongue

exceeds lipforward movement of upper anterior teethLower lip finds a place behind upper anterior teeth causing more

pressure on forwarded teeth to move more forwards and causes backwards pressure on lower anterior teeth to crowd lingualy.

|Treatment|

Should involve removal

of the cause and stop of tongue

thrust to realign the teeth.

Besides the clinical examination, analysis of the case

with mounted study casts is essential.

Face bow record to orient the maxilla to the condylar

axis and jaw relation records are essential to mount the

lower jaw on an adjustable articulator.

Mounted casts are essential to analyze the extent of

teeth involvement in the process of functional

disharmony.

The functional harmony means a peaceful neuromusculr, articular and dental relations during all the possible functions of the

masticatory system.

This will enable the system to function on demands to its anatomic limits without interferences.

Occlusal Stability:

The Essence of Anatomic and Functional harmony is BALANCE: It is a centered relationship between equal opposite forces.

Many examples explain the concept of balance in the human body

- Osmotic balance between intracellular and extracellular fluids.- Nervous system balance between sympathetic and parasympathetic.


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|Fact|

The body responds to antagonistic forces in

a dynamic way until the opposing forces are

equalized.

Teeth will not stay stable where muscles do not

want them to be (Neutral Zone).

Understanding the concept of balance will enable

the operator to recognize why, how and when each

part of the masticatory system is either in peaceful

balance or stressful disharmony.

Balance exists for teeth relations, muscular relations and TMJ relations to attain occlusal stability

Class I relation is not necessarily a stable occlusion, teeth alignment change horizontally and vertically by the

forces acting against them until they remain stable when these forces are in equilibrium.

- Stability of horizontal alignment of teeth is governed by the equilibriumof forces acting from inside (tongue) and the forces acting from outside

(orbicularis oris and buccinator ) to locate the teeth in the neutral zone.

- Stability of vertical alignment is governed by the equilibrium betweenthe eruptive forces of the antagonistic teeth and the equilibrium

between the action of the mandibular elevator and depressor muscles.

The point of balance between the opposing forces vertically is the occlusal plane.

The indiscriminate use of bite plane can cause disruption of an existing harmony and

equilibrium.

The anteroposterior balance of the mandible is determined by the harmonious function of

the lateral pterygoid muscle versus the fibers of temporalis to position the condyle in the

various functional positions at the slope of the eminence simultaneously during action.

The disk position is balancedbetween the opposing forces of the elastic fibers behind the

disk and the superior belly of the lateral pterygoid muscle in front.

|VIP|

Understanding the concept of balance in all aspects of the entire masticatory system together with the an atomic and functional

harmony will enable the operator to judge the best way to restore a maintainable health of the masticatory system = concept of

Complete Dentistry.

|Avoid|

Empiric approaches, unnecessary interference, gimmickry procedures and overtreatment .

Explaining the treatment rationale to the patient, tell the patient that in order to make and keep his mouth healthy two things must

be accomplished by the operator:

We must have no place in the mouth which is not

completely cleanable

We must reduce all stresses to be non destructive

Tell the patient that his responsibility is

- To keep his mouth clean- To report any uneven stress- To maintain general health (diet & exercise)

(2) Col Occlusion

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