OCCLUSAL SCHEMES

IN COMPLETE DENTURE

Muneeb Muhammed AliRoll No:47

III BDS

INTRODUCTIONOCCLUSION:

Occlude means to “CLOSE” “The static relationship between the incising or

masticating surface of the maxillary or mandibular teeth or tooth analogues” (GPT 8)

It is important to plan occlusal scheme prior to selection and arrangement of artificial teeth

Requirements of complete denture occlusion:Cutting,Penetrating and shearing efficiency of occlusal

surface

Minimum occlusal contact areas

Reduced posterior cusp height to control horizontal forces

Reduced buccolingual width of posterior teeth to decrease forces transmitted to residual ridge

Stability of occlusion at centric relation position and in area forward and lateral to it

Stability of occlusion in centric and eccentric relations

Balanced occlusal contacts

Types of complete denture occlusion

Balanced Occlusion

Monoplane Occlusion

Lingualized Occlusion

BALANCED OCCLUSION:-“The bilateral,simultaneous,anterior and

posterior occlusal contact of teeth in centric and eccentric positions” (GPT8)

It is not seen in the natural teeth,if it occur in natural teeth it is considered as premature contact on non working side and considered as pathologic

It enhances the stability of denture

Balance in complete denture is unique and man made

Types of balanced occlusion1.Unilateral lever balance2.Unilateral occlusal balance3.Bilateral occlusal balance4.Protrusive occlusal balance

Unilateral lever balance:-This is present when there is equilibrium of the base on its supporting structures when a bolus of food is interposed between the teeth on one side and a space exist between the teeth on the opposite side

Bilateral occlusal balance• This is present when there is equilibrium on both sides of denture due to

simultaneous contact of teeth in centric and eccentric occlusion

• It requires a minimum of a three contacts for establishing a plane of equilibrium,the more the contacts the more assured equilibrium

Unilateral occlusal balanceThis is present when the occlusal surfaces of teeth on one side articulate simulataneously as a group with a smooth uninterrupted glide

Protrusive occlusal balance• This is present when the mandible moves essentially forward and

the occlusal contacts are smooth and simultaneous in the posterior both on right and left sides and on anterior teeth

• It is slightly different from bilateral balance in that it it requires a minimum of three contacts (one on each side posteriorly and one anteriorly)

Factors affecting balanced occlusion1.Condylar Guidance

2.Incisal Guidance

3.Plane of Occlusion

4.Compensating Curves

5.Cuspal Inclination

1.Condylar Guidance“The mechanical form located in the upper posterior region

of an articulator that controls movement of its mobile member (GPT8)”

Increase in condylar guidance will increase the jaw separation during protrusion.this factor cannot be modified,so in patients with steep condylar guidance incisal guidance is decreased to prevent the posterior jaw separation

2.Incisal Guidance“The influence of the contacting surfaces of the

mandibular and maxillary anterior teeth on mandibular movements” (GPT8)

Incisal guide angle:-The angle formed between horizontal plane of occlusion and a line drawn in the sagittal plane between the incisal edge of the maxillary an mandibular central incisors when the teeth are in maximum intercuspation

It is determined by dentist during anterior try in

it should never be greater than the condylar guidance

3.Plane of occlusion“The average plane established by the incisal and occlusal

surfaces of the teeth.Generally it is not a plane but represents the planar medium of the curvature of these

surfaces” (GPT8)

It is established anteriorly by the height of the lower canine and posteriorly by the height of the retromolar pad

4.Compensating Curves“The anteroposterior and lateral curvatures in the

alignment of the occluding surfaces and incisal edges of the artificial teeth that are used to develop a balanced

occlusion”1.Anteroposterior compensating curve (curve of spee):-

“The anatomic curve established by the occlusal alignment of the teeth,as projected onto medial plane,beginning with the cusp tip of the mandibular canine and following the buccal cusp tip of premolar and

molar teeth continuing through the anterior border border of the mandibular ramus,ending with the anterior most portion of the

mandibular condyle” (GPT8)

Described by Ferdinand Graf Spee in 1890

• Signifance of curve of spee is when the patient move s his mandible forward,the posterior teeth set on this curve will continue remain in contact,thus avoiding disocclusion

2.Lateral Compensating curves1.Curve of Monson:- ”Curve of occlusion in which each cusp and incisal edge touches or conforms to a segment of the surface of a sphere 8 inches in diameter with its diameter with its centre in the region of glabella” (GPT8)

2.Reverse Curve or Anti monson curve:A cuve of occlusion that is convex upwards and usually used to arrange the first premolars

3.Curve of Wilson: This curve that is convex downwards .the lower teeth are inclined lingually giving prominence to buccal cusps and bringing them into heavy occlusal contact with the upper buccal cusp during lateral movement on working side

4.Pleasure Curve:- This combination of monson and anti monson curves .hence it is not single curve but combination of curve

It was used for arranging non anatomic teeth in balanced occlusion

5.Cuspal Inclination“The angle made by the average slope of a cusp with the cusp plane measured mesiodistal or buccolingually.also

called as Cusp Angle”(GPT)

It is an important factor that modify the effect of plane of occlusion and compensating curves

Mesiodistal cusps are reduced to prevent the locking of cusps

Advantage:- Bilateral simultaneous contact help to seat the denture in a stable

position during mastication,swallowing and maintain retention

Denture bases are stable even during bruxing activity

Cross arch balance

Disadvantage:- It is difficult to achieve in mouths where an increased

vertical incisor overlap is present-class II Cases

It may tend to encourage lateral and protrusive grinding habits

A semi adjustable or fully adjustable articulator required

MONOPLANE OCCLUSION“An occlusal arrangement where in the posterior

teeth have masticatory surfaces that lack any cuspal height”(GPT8)

Occlusal arrangement using non anatomic teeth

Anterior teeth are arranged with an overjet of 2mm and no overbite

Monoplane occlusion can be balanced by placing balanced ramps distal to second molar,it will improves horizontal stability of denture

Ramps

Advantage:-They are more adaptable to unusual jaw relation such as

class II and class III relationsEasy to arrange teeth and less time consumingThey eliminate horizontal forces,more damaging than

vertical forcesThey accommodate better to the negative change in the

ridge height that occur with agingSimple non adjustable articulator is sufficient

Disadvantage:-No vertical Component to aid in shearing during

masticationLack of positive intercupationPoor Appearance

LINGUALIZED OCCLUSION“This form of denture occlusion articulates the maxillary lingual cusps with the mandibular occlusal surfaces in centric working

and non working mandibular positions” first described by S Howard Payne in 1941 (GPT8)

Lingualized occlusion can be a type of bilaterally balanced occlusal cheme

Anatomic tooth are used in maxilla opposing a flat cusped or shallow cusped mandibular tooth

Forces directed towards lingual side

Maxillary lingual cusp articulates with mandibular central fossae

Advantage:- Cusp form is more natural in appearance compared to non anatomic forms Good penetration of bolus is possible this may reduce the lateral chewing

component Both anatomic and non anatomic tooth forms are retained Simple technique Can be used in Class II,Class III,IV And cross bite situations

Disadvantage:- Wearing of maxillary lingual cusp or mandibular fossa More challenging teeth arrangement than monoplane occlusion

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