INTRODUCTION &

CLASSIFICATION OF

REMOVABLE PARTIAL DENTURE

MADE BY:

Abhinav Mudaliar(2010-

2011)

DEFINITION- PROSTHODONTICS

Defined as the “branch of dentistry pertaining

to the restoration and maintainence of oral

function,comfort,appearance and health of

the patient by restoration of natural teeth or

the replacement of missing teeth and

contiguous oral and maxillofacial tissues with

the artificial substitution.

BRANCHES

3 major divisions:

-fixed prosthodontics

-maxillofacial prosthetics

-removable prosthodontics

complete partial

extracoronal intracoronal

REMOVABLE PROSTHODONTICS

It is devoted to replacement of missing teeth &

contigous tissues with prosthesis designed to be

removed by the wearer.It includes two disciplines:

removable complete denture prosthodontics and

removable partial denture prosthodontics. A RPD

may be extracoronal or intracoronal depending on

what type of retention is used to keep it in the

mouth.

COMMON TERMINOLOGIES USED IN RPD

ApplianceIt is a device worn by a patient in the course

of treatment. e.g. orthodontic appliance, surgical ,space maintainer.

Abutment“A tooth,a portion of a tooth ,or that portion of a dental implant that serves to support & or retain a prosthesis.”

RetainerThe fixation device ,or any form of attachment

applied directly to an abutment tooth & used for the fixation of a prosthesis, is called retainer.

Extracoronal partial dentureThe retention of this prosthesis depends on the exact

parallelism of the two retentive units.

Tooth supported RPDA partial denture that receives support from the natural

teeth at each end of the edentulous space or spaces.

Tooth tissue supported RPDThe denture base that extends anteriorly/ posteriorly

and is supported by teeth at one end and tissue on the other end – distal extension partial dentures.

Temporary removable partial denture

They are used in patient where tissue

changes are expected, where a permanent

prosthesis cannot be fabricated till the

tissues stabilize.

Interim denture

It is a temporary partial denture used for a

short period to fulfill aesthetics, mastication

or convenience until a more definite form of

treatment can be rendered.

Transitional denture

May be used when loss of additional teeth is inevitable but immediate extraction is not advisable or desirable. Artificial teeth may be added to the transitional denture as and when the natural teeth are extracted.

Treatment denture

It is used as a career for treatment material. It is used when the soft tissues have been abused by illfitting prosthetic devices.

Centric relation

It is the most posterior relation of mandible to

the maxilla at the established vertical dimension

from which lateral movements could be made.

Eccentric Relation

Relationships of the mandible to maxilla other

than centric relation that occur in horizontal plane.

Centric Occlusion

It is the maximum intercuspation between the

upper and lower teeth.

INDICATIONS FOR RPD Length of edentulous: RPD preferred for longer

edentulous arches.

Abutment tooth: When there is no tooth posterior to the edentulous space to act as an abutment, a RPD is preferred.

Periodontal support of remaining teeth: When it is poor RPD is preferred because it requires less support from the abutment teeth.

Cross arch stabilization: When a remaining teeth have to be stabilized against lateral and anterior-posterior forces, a RPD is indicated.

Excessive bone loss: In RPD, the artificial tooth can

be positioned as per the operators preferences and

the denture base can be fabricated to provide required

support and aesthetics.

Aesthetics: RPD provide better aesthetics because

the denture base gives the appearance of a natural

tooth arising from the gingiva.

Immediate tooth replacement after extraction

Emotional problems: The appointment for removable

partial denture is shorter and less demanding to

patient.

Patient desires: Patient insist on RPD over FPD for

the following reasons:

To avoid operative procedures on normal tooth.

For economic reasons.

RPD IS GENERALLY PREFERRED IN THE

FOLLOWING CONDITIONS:

When more than 2 posterior teeth or 4 anterior teeth are missing.

If the canine & two of its adjacent teeth are missing.

When there is no distal abutment tooth.

Presence of multiple edentulous spaces.

If the teeth adjacent to edentulous spaces are tipped ,they cannot be used as an abutment for a fixed prosthesis.

If periodontally weakened teeth are present near the edentulous spaces.

Teeth with short clinical crowns.

Insufficient number of abutments

Severe loss of tissue on the edentulous

space.

Old patients

REQUIREMENTS OF AN ACCEPTABLE METHOD

OF CLASSIFICATION .

It should permit immediate visualization of

the type of partially edentulous arch that is

being considered.

It should permit immediate differentiation b/w

the tooth supported & the tooth and tissue

supported RPD.

It should be universally acceptable.

CLASSIFICATION OF REMOVABLE PARTIAL

DENTURE:

Requirements of classification:

Allow visualization of the type of partially

edentulous arch that is being considered.

Allow differentiation between tooth supported

and tooth-tissue supported partial dentures.

Serve as a guide to the type of design to be

used.

Be universally accepted.

There are many classification available for

classifying edentulous arches. The most

common ones are:

CUMMER’S CLASSIFICATION:

This is the first professionally recognized classification. It

was introduced by Cummer in 1920.

According to him partial dentures can be classified into

four types based on the position of direct retainers:

Diagonal: Two direct retainers are diagonally opposite

to one another.

Diametric: Two direct retainers are diametrically

opposite to one another.

Unilateral: Two or more direct retainers present on the

same side.

Multilateral: Three(rarely four) direct retainers in a

triangular(rarely quadrangular) relationship.

KENNEDY’S CLASSIFICATION

Class I: bilateral

edentulous areas

located posterior to

the remaining

natural teeth.

Class II: unilateral

edentulous areas

located posterior to

the remaining

natural teeth.

Class III: unilateral

edentulous area with

natural teeth anterior

and posterior to it, i.e.

this indicates a single

edentulous area which

doesn’t cross the

midline of the arch,

with teeth present on

both sides of it.

Class IV: single,

bilateral edentulous

area located anterior

to the remaining

natural teeth. This is a

single edent. area,

which crosses the

midline of the arch,

with remaining teeth

present only posterior

to it.

APPLEGATE'S MODIFICATION (1960)

Applegate modified the above classification

based on the condition of the abutment to

include 2 or more additional groups:

Class V: edent. area

bounded anteriorly

and posteriorly by

natural teeth but in

which the anterior

abutment (e.g. LI) is

not suitable for

support. It is basically

a class III situation for

the anterior abutment

cannot be used for

any support.

Class VI: edent. area in which the teeth adj.to the space are capable of total support of the required prosthesis. This denture hardly requires any tissue support. Most of the RPDs are tooth tissue supported. Hence this condition is classified as a separate group.

APPLEGATE’S RULES

Rule 1: classification should follow rather than precede extractions that might alter the original classification.

Rule 2: if the third molar is missing and not to be replaced, it is not considered in the classification.

Rule 3: if the third molar is present and is to be used as an abutment, it is considered in the classification.

Rule 4: if the second molar is missing and is not to be replaced, it is not considered in the classification.

Rule 5: the most posterior edentulous area or areas always determine the classification.

Rule 6: edentulous areas other than those, which determine the classification, are referred to as modification spaces and are designated by their no:

Rule 7: the extend of the modification is not considered, only the no: of edentulous areas, i.e. the no: of teeth missing in the modification spaces is not considered only the no: of additional edentulous spaces are considered.

Rule 8: there can be no modification areas in

class IV. Because any additional edentulous

space will definitely be posterior to it and will

determine the classification.

BECKETT & WILSON’S CLASSIFICATION

They decided that the following must be considered while determining the prpportionate amount of support provided by the teeth & tissue.

a)the quality of abutment support. b)the magnitude of occlusal support. c)the harmony of the occlusion. d)the quality of the mucosa &residual ridge.

class I:bounded saddle.abutment teeth qualified to support the denture.mucosa is not used for support.

Class II:free-end a)tooth-&- tissue-borne b)tissue-borne.

Class III:bounded

saddle.abutment

teeth not so

qualified to support

the denture as

described in classI.

BAILYN’S CLASSIFICATION

Proposed by Bailyn,it was the first classification to give importance to support of partial dentures by remaining tissues.he used descriptive letters like A& P .A-anterior restorations,where there are saddle areas antr to the 1st bicuspid P-posterior restoration, where there are saddle areas posterior to the canine.

FURTHER THEY ARE SUBCLASSIFIED AS

FOLLOWS:

classI: bounded

saddle(not more

than 3 teeth

missing)

Class 2:free end

saddle(there is

no distal

abutment tooth)

Class 3:bounded saddle(more than 3 teeth missing)

Class1 is tooth supported,class2&3 are tooth-tissue supported.In cases where anterior & posterior teeth are missing ,the class of anterior &posterior teeth are mentioned seperately,eg:A1P1,A2P1,A1P3.

NEUROHR’S CLASSIFICATION:

Proposed in 1939, it is also based on support derived.Itis not commonly used due to its unnecessary complexity.

Class I:Tooth-bearing

A unilateral or bilateral case falls into the above classification when there are teeth posterior to all spans and when there are no more than four teeth missing in any space. There are two possible variation in this class.

Variation 1:Missing posteriors predominate.

--- Posteriors missing, anteriors in place.

--- Posteriors missing, some anteriors missing.

Variation 2:Missing anteriors predominate.

--- Anteriors missing, posteriors present.

--- Anteriors missing, some posteriors missing.

Class II: Tooth and tissue-bearing

A unilateral or bilateral case falls into the above classification

when there are no teeth posterior to one or more spans or

when there are more than four teeth(which include a

canine) in one or more spans. Class II is further sub-

divided into divisions with variations under each:

Division 1:When there are no teeth posterior to one or more

spans:

Variation 1:Missing posteriors predominate.

---Posteriors missing, anteriors in place

---Posteriors missing, some anteriors missing

Variation 2:Missing anteriors predominate.

---None

---Anteriors missing , some posteriors missing

Division 2: When there are teeth posterior in all spans,

but when there are more than four teeth(including a

canine) in any one or more spans.

Variation 1:Missing posteriors predominate.

--- None

--- Posteriors missing, some anteriors missing

Variation 2:Missing anteriors predominate.

--- Anteriors missing, posteriors in place

--- Anteriors missing, posteriors missing

Class III: Tissue bearing complete dentures

MAUK’S CLASSIFICATION:

Proposed by Mauk in 1942, it is based on number,

length and position of the remaining teeth.

Class I: Bilateral space with no teeth posterior to it.

Class II: Bilateral space with teeth present posterior to

one space.

Class III: Bilateral space with teeth present posterior to

both spaces.

Class IV: Unilateral space with no teeth posterior to it.

Class V: Anterior space with unbroken posterior

arches on both sides.

Class VI: Irregular spaces around the arch. The

remaining teeth are single or in small groups.

GODFREY’S CLASSIFICATION:

Proposed in 1951, it is based on the location and size

of edentulous spaces.

Class A: Tooth-borne denture base in the anterior part

of the mouth. It may be an unbroken five- tooth space,

broken five-tooth space or an unbroken four-tooth

space.

Class B: Mucosa-borne denture base in the anterior

region. It may be an unbroken six-tooth space, an

unbroken five-tooth space, or a broken five-tooth

space.

Class C: Tooth-borne denture base in the posterior

part of the mouth. It may be an unbroken three-tooth

space, a broken three-tooth space, an unbroken two-

tooth space, or a broken two-tooth space.

Class D: Mucosaborne denture base in the

posterior region. It may be an unbroken four-

tooth, three-tooth, two-tooth, or a single-tooth

space.