INTRODUCTION & CLASSIFICATION OF REMOVABLE PARTIAL DENTURE MADE BY: Abhinav Mudaliar(2010- 2011)
Jul 14, 2015
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.