article 11

ABSTRACT:

Complete denture is a prosthesis that should be a source of pride for every dentist. Most complete dentures have either limited function or are the reverse of esthetics. The type of occlusal concept chosen will influence esthetic requirements, comfort, masticatory efficiency and stability of complete dentures. However it is interesting that none of these occlusal concepts are accepted universally and that all of these occlusal concepts have been accepted by segments of the dental profession with a very little long term scientific research. The dentist must therefore rely on his clinical judgment and experience in the choice of occlusal concepts. This paper discusses various concepts for complete dentures.

Key words: complete dentures, occlusal concepts, esthetics, stability

INTRODUCTION:

Occlusal concepts and their resulting functions are

of concern to the dentist so that loss of remaining

tissues of the mouth, which may be attributed to the 1malocclusion can be minimized. Search for ideal

denture occlusion has been going on for almost two

centuries in an effort to find the tooth form which

provides maximum stability and masticatory

efficiency without compromising the health of 2 underlying bone. The dynamic contact of the teeth

has an effect on the stability of denture base ,the

forces transmitted to denture bearing tissues , 3 comfort and functions experienced by patient.

Several dental practitioners and proponents have

made modification to the original posterior tooth

form and arrangement to satisfy more fully the

demands of denture constructions. Occlusal scheme

refers to the type or types of tooth forms or molds

(cusps or non cusp teeth) that the dentist selects to 4

establish occlusal concept.

Five basic occlusal schemes currently used are

anatomic occlusion, non anatomic (zero degree, non

cusp, monoplane) occlusion, semi anatomic

occlusion, lingualized (linear, organic) occlusion,

and neutrocentric occlusion.

The controversy about occlusion concept cannot be 5resolved for three reasons.

1. Much knowledge is based upon empherical

rather than scientific information.

2. The tolerance of the oral organ or upper and

lower physiologic limits are so board that if

certain concept failed in one specific mouth, it

does not mean that it will fail in all mouth.

3. The tremendous variable factors of individual

dentists and the standards by which they

complete restorations.

1. ANATOMIC OCCLUSION:

Anatomic teeth are by definition teeth with a

cuspal inclination of 30 degree or more are

intended to duplicate masticatory surface of 6

natural teeth.

INDICATION:

1. To achieve a more esthetic and natural

appearance

2. To achieve stability, comfort and function by

having teeth contact during all ranges of

functional and non functional movements.

Review Article

Occlusal Schemes for Complete Dentures - A Review Article.

ADDRESS FOR CORRESPONDANCE:Dr. Savitha K. C.No. 216, B – 5, Krishna block,National games village, Near commercial tax office, Kor Mangala, Banglor – 560095.Email: [email protected]

Authors: Savitha K. C.*, Srinivas L. Shantaraj**

BHAVNAGAR UNIVERSITY'S JOURNAL OF DENTISTRY 67

*Sr Lecturer, Department of Prosthodontics and Crown and Bridge, The Oxford Dental College and Hospital, Bangalore.**Sr Lecturer, Department of Pedodontics, K. M. Shah Dental College and Hospital, Vadodara, India.

Vol. 3 Issue-1 Jan. 2013

B U J O DB U J O D Savitha et al

ADVANTAGES:

7,8,9According to Payne, Bascom, Brewer.

1. Penetrates food easily requiring less chewing

force thereby reducing vertical force on the

ridge.

2. The interdigitation of denture teeth resists the

rotation of denture by encouraging a more

vertical chewing pattern thereby providing

g r e a t e r d e n t u r e s t a b i l i t y d u r i n g

parafunctional movements.

3. Achieve better esthetics and natural

appearance.

4. Acts as a guide for proper jaw closure.

DISADVANTAGES:

1. Precise reproducible records are required to

generate this occlusion on the articulator 2,10which is time consuming.

2. With slight ridge resorption occlusal position

of denture changes which is more difficult to

adjust

3. Anatomic occlusion generates greater lateral

forces against the residual ridges resulting in 2

ridge resorption.

4. Anatomic occlusion causes greater denture

base deformation which means greater

lateral forces were generated against residual 11

ridge .

5. Use of anatomic occlusion with tight

interdigitation of cusp makes it difficult for 12use in class II and class III jaw relation.

6. Occlusal balance achieved is totally

mechanical and exists only on articulator as

most of the articulators used do not

reproduce the exact movements of mandible

and it is only approximation.

2. NON ANATOMIC (MONOPLANE, NON CUSP,

ZERO DEGREE) OCCLUSION:

The complex denture procedures using

anatomic occlusion was associated with the

use of highly adjustable articulators enjoyed

widespread popularity in the past but it is

significant that all such aforementioned

articulators are no longer available. Some

pioneer dentist observed that the comfort and

efficiency of dentures did not increase in the

cuspal height of the more natural looking

posterior tooth forms but in many instances 13 the opposite occurred. Non anatomic

teeth are set with compensating curve to

provide some degree of protrusive and lateral

balance and tooth inclines are eliminated and

balancing is achieved by balancing ramp

leading to three point balance.

INDICATIONS:

1. Good for class II and class III malocclusion

who hold jaw in forward position

2. for patients with cross bite

3. for patients with parafunctional movements

ADVANTAGES:

1. It is simple and less time consuming than

other occlusal scheme

2. Accommodates better to inevitable negative

changes in ridge height that occur with aging. 13

3. It is more esthetic than neutrocentric

occlusion because some degree of vertical

overlap is allowed in presence of posterior

compensatory curves

DISADVANTAGES:

1. The use of zero degree teeth does not

necessarily result in a monoplane occlusion

because they may be set to a curve or may be

set with balancing units resulting in one or 13

more additional planes.

2. Compensatory curve acts as one long cusp

therefore it will produce the same damaging

effect to cuspal inclines

3. Have no cusp inclines therefore balancing 14

contacts most be obtained by other means.

4. Customized balancing ramps must be placed

posterior to the most distal mandibular

molars to provide contact with maxillary


B U J O DB U J O D


15denture in all excursions.

5. Due to presence of compensatory curves

difficult for adjustment

3. SEMI ANATOMIC OCCLUSION:

Semi anatomic teeth have cuspal inclination of

less than 30 degree. It is indicated for patients

who desire cusps for esthetics, chewing

efficiency, balance and to decrease the lateral

force component introduced by cuspal

inclines. It has the advantages and

disadvantages same as that of anatomic

occlusion.

4. LINGUALIZED OCCLUSION:

Lingualized occlusion is an attempt to

maintain the esthetic with advantages of the

anatomic form while maintaining the

mechanical freedom of non anatomic form.

Lingualized occlusion utilizes anatomic teeth

for the maxillary denture and modified non

anatomic or semi anatomic teeth for

mandibular denture.

The umbrella term lingualized occlusion can

be used in many ways encompassing linear,

organic, balanced, nonbalanced, functional-

rational and functional occlusion

The basic concepts of lingualized occlusion

was first suggested by Payne.Pound discussed

a similar occlusal concepts and used the term 2

lingualized occlusion.

2According to Becker Principles of lingualized

occlusions are:

1. Anatomic posterior (30-33 degree) teeth are

used for maxillary denture

2. Non anatomic or semi anatomic teeth are used

for mandibular denture

3. Modification of mandibular posterior teeth is

accomplished by selective grinding

4. Maxillary lingual cusp contact mandibular

teeth in centric occlusion

5. Balancing and working contacts should occur

only on the maxillary lingual cusps.

6. Protrusive balancing contacts should occur

only between the maxillary lingual cusp and

lower teeth

INDICATIONS:

1. In patients with high priority on esthetics but

a non anatomic occusal scheme is indicated by

oral conditions such as severe alveolar

resorption with lingualized occlusion the

esthetic result should be greatly improved

still maintaining the advantages of non

anatomic system.

2. In class II and class III and cross bite cases

3. In patients with displaceable supporting

tissues

4. Can be used effectively when a complete

denture opposing removable partial denture

as in case of Combination Syndrome (linear

occlusion)

ADVANTAGES:

1. Most of the advantages attributed to both

anatomic and non anatomic forms are

retained

2. It increases maxillary and mandibular

denture base stability in severely resorbed

mandibular ridges by providing a central 16,17,18

bearing area during recording process.

3. Cusps have better penetrating power and

therefore decrease the vertical forces placed 2

on the residual ridges.

4. Mastication in this occlusal form is as much

holding and grinding motar and pestle type as

it is shearing type which is exerted with 19

anatomic balanced occlusion.

5. Use of cusp form is more natural in

appearance providing better esthetics

especially if a balanced occlusion is used

which allows some incisal overlap.

6. Simple technique requires less precise

records

7. No post insertion adjustments for tissue

irritation was needed

BHAVNAGAR UNIVERSITY'S JOURNAL OF DENTISTRY 69Vol. 3 Issue-1 Jan. 2013


8. Reduce transverse vectors and provide

consistent vertical force in both centric and

non centric mandibular movements thus 20,21improving stability.

DISADVANTAGES:

1. Although lingual occlusion can be achieved

using acrylic opposing acrylic ,use of

porcelain-porcelain occlusion is most

resistant to wear but has disadvantages of

increased clicking sound during mastication

which may be disturbing to the patient and it 3,18is more difficult to adapt to porcelain teeth.

2. Lingual occlusion can occasionally cause

esthetic concern when flat plane teeth are set 22

on maxillary arch.

5. NEUTROCENTRIC OCCLUSION:

Neutrocentric occlusion is exact opposite of

anatomic occlusion. Devan coined the term

neutrocentric to embody the two key

o b j e c t i v e s t h e n e u t r a l i z a t i o n a n d

centralization of forces. According to 2 3

Devan. there are f ive e lements in

neutrocentric occlusion

1. Position- Devan positioned the posterior

teeth over the posterior residual ridge as far

lingually as the tongue would allow so that

forces would be perpendicular to the

supporting areas

2. Proportion- tooth width is reduced such that

narrowing supposedly reduced vertical

stress on the ridge by narrowing occlusal

table

3. Pitch (tilt, inclination) - tooth pitch was

corrected by placing the occlusal plane

parallel to the underlying ridges and midway

between them. This positioning directed

forces perpendicular to osseous foundation

and there was no compensatory curve and

incisal guidance.

4. Form- tooth form was corrected by using flat

teeth with no deflecting inclines. This

arrangement reduced destructive lateral

forces and helped to keep masticatory forces

perpendicular to the supporting areas

5. Number- the posterior teeth was reduced in

number from eight to six .This decreased the

magnitude of occlusal force and centralized to

second premolar and first molar areas

INDICATIONS:

1. For class II and class III jaw relations and cross

bite cases

2. In case of poor ridges for good stability as 19

forces can be centralized and neutralized.

3. In geriatric patients with poor ridges the

chances for arch relationship discrepancies

are increased so neutrocentric occlusion with

greater horizontal overlap and lack of specific

interdigitation makes it ideal for such kind of

patients

4. In patients with excessive inter-ridge distance

as it reduces lateral forces

5. Ideal for patients in whom it is difficult to

make precise records

ADVANTAGES:

1. This technique is simple and requires less

precise records hence is helpful in patients in

whom it may be difficult or impossible to

make precise records.

2. It provides an area of closure and does not

lock the mandible into a single position so it is

useful in geriatric patients with limited oral

dextricity

3. Easy to adjust the teeth set

4. Decreased lateral forces by removing inclines

thereby preventing further resorption of

ridges and helpful in patients with excessive

inter-ridge distance by reducing lateral force.

DISADVANTAGES:

1. Flat type of occlusion cannot be balanced and

the lack of cuspal heights encourages a lateral

component to the chewing cycle leading to 24

bruxism, ridge soreness and TMJ problems.

2. In case of class II cases patients who tend to


B U J O DB U J O D


hold their jaws forward of centric relation

results in disocclusion of the posterior teeth '

due to Christensen s phenomenon causing

soreness in anterior area of mouth as forces 24are not perpendicular.

3. Least esthetic of the five occlusal concepts as

there is no mesial overlap and no posterior

cusps. However few never mention lack of

cusps or incisal guidance as a problem unless 12the dentist points out.

4. Flat nature of cusp impairs mastication

because of poor bolus penetration; as a result

vertical forces on the ridge are increased.

Patients may complain that the teeth ''feel [\25dull''.

5. There is no denture stability during 19

parafunctional movements .

DISCUSSION:

The complex denture procedures associated with

the use of highly adjustable articulators for

anatomic occlusion enjoyed widespread popularity

in the past. It is significant that all such

aforementioned articulators are no longer available. 13However anatomic tooth forms have progressed to

a point halfway down the front steps. Problems arise

when the patient presents with factors that do not

'fit' the classic clinical 'class I skeleton' because

none of the available posterior tooth forms can be

used in developing a balanced occlusion without

either extensive modifications or sacrificing 4 philosophy or the concept of balanced occlusion.

Non anatomic tooth mold was introduced to permit

a maximum range of movement for patients with 4

anterior posterior discrepancies. It has been the

experience of the authors that the use of linear

occlusion in conjunction with a steeper than

conventional occlusal plane assists in stabilizing 22

mandibular denture base. In neutrocentric

occlusion denture stability improved by taking

maximum advantage of mechanical aspects of

denture construction. However an ideal positioning 23

of the natural teeth is rarity. Occlusal patterns in

different arrangements must exert their influences

not only on the maintenance of the soft and hard

tissues of the oral cavity as well as the degree and

length of time in maintaining comfort to the patient.

CONCLUSION:

Presently it is not known which concept of occlusion

is more favorable for continued maintenance of oral

tissues and the long term comfort of patient. Until

several extensive long term investigations are made.

The dentist must therefore rely on his clinical

judgments and experience in the choice of occlusal

concepts for edentulous patients.

REFERENCES:

1. B e c k H O. O c c l u s i o n a n d re m ova b l e

prosthodontics. J Prosthet Dent1972; 27:245-

56.

2. Becker CM, Swoope CC, Guckes AD.

Lingualized occlusion for removable

prosthodontics. J Prosthet Dent 1977;

38:601-8.

3. Lang BR.Complete denture occlusion. Dent

Clin North Am 1996; 40:85-91.

4. Lang BR, Razzog ME.A practical approach to

restoring occlusion for edentulous patient.

Part I: Guiding principles of tooth selection

Prosthet Dent 1983; 50:455-61.

5. Kahn AE.Unbalanced occlusion in occlusal

rehabilitation. J Prosthet 1964; 14:725-38.

6. Glossary of prosthodontic terms ed 4. St Louis.

The CV Mosby Co1977.

7. Payne SH.A comparative study of posterior

occlusion. J Prosthet Dent 1952; 2:661-6.

8. Bascom PW. Masticatory efficiency of

complete dentures. J Prosthet Dent 1962;

12:453-9.

9. Brewer A, Reibel PR, Nassif NJ.Comparison of

zero degree teeth and anatomic teeth on

complete teeth Prosthet Dent 1967; 17:28-35.

10. Beresin M.A biomechanical approach to the

problem of prosthetic occlusion. J Prosthet

Dent 1956; 6:472-6.

BHAVNAGAR UNIVERSITY'S JOURNAL OF DENTISTRY 71Vol. 3 Issue-1 Jan. 2013


11. Swoope CC, Kydd WL.The effect of cusp form

and occlusal surface area on denture base

deformation Prosthet Dent 1966; 34:16-19.

12. Smith DE.The simplification of occlusion in

complete denture practice: Posterior tooth

forms and clinical procedures. Dent Clin

North Am 1970; 14:493-17.

13. Jones PM.The monoplane occlusion for

complete dentures. J Am Dent Assoc 1972;

85:94-101.

14. Nimmo A, Kratochvil FJ.Balancing ramps in

non anatomic complete denture occlusion


15. Nepola SR.Balancing ramps in prosthetic

occlusion Prosthet Dent 1958; 8:776-9.

16. Kingery RH.A review of some of the problems

associated with centric relation. J Prosthet

Dent 1952; 2:307-19.

17. Kapur KK, Yurkstas A. An evaluation of centric

relation records obtained by various

techniques Prosthet Dent 1957; 7:770-86.

18. Gronas DG, Stout CJ.Lineal occlusion concepts

for complete dentures.J Prosthet Dent 1974;

32:122-9.

19. Heartwell CM, Rahn AO: Syllabus of complete

dentures.ed 5.Philadelphia.Lea and Fibiger

1993.

20. Winkler S: Essentials of complete denture

prosthodontics.ed 2. Philadelphia, PA, WB

Saunders 1996.

21. Porter C. Simplicity versus complexicity .J


22. Williamson RA,Williamson AE,Bowley

J,Toothaker R.Maximizing mandibular

prosthesis stabil i ty uti l izing l inear

occlusion,occlusal plane selection and centric

recording J Prosthodont 2004;13:55-61.

23. Devan MM.The concept of neutrocentric

occlusion as related to denture stability. J Am

Dent Assoc 1954; 48:165-71.

24. Boucher CO. Occlusion in prosthodontics. J


25. Kaires AK.Occlusal surface contacts during

mastication. J Prosthet Dent 1957; 7:553-9.


B U J O DB U J O D

Source of Support :

Conflict of Interest :

Date of Submission :

Review Completed :

NIL

NOT DECLARED

09-09-2012

05-12-2012


article 11

Documents