The Prime purpose for creating a classification system for partially dentulous arches is to enable the dentist

to clearly communicate to a listener or reader the condition of an oral cavity in which missing teeth are to be replaced with a prosthesis.

An additional benefit of a workable classification system is that it is a contributing aid in the learning of the fundamentals of design.

Swenson classification system 1905Cummer’s classification system 1922Kennedy’s classification system 1925Bailyn’s system 1928Neurohr’s system 1939Mauk’s system 1942Beckett’s system 1953Friedman’s system 1954The Austin-Lidge classification system 1957Skinner’s system 1959Applegate-Kennedy’s system 1960

The four primary classes represent only slight

modification of the kennedy’s system, whereas the

modifications of these four classes are changed

more drastically.

Class I – An arch with one free end denture base.

Class II – an arch with two free end denture bases.

Class III – an arch with an edentulous space posteriorly on one or both sides of the mouth but with teeth present anteriorly and posteriorly to each space.

Class IV – an arch with an anterior edentulous space and with five or more anterior teeth missing.

Swenson’s class I partially Swenson’s class II partially edentulous condition edentulous condition

Swenson’s class III partiallyedentulous condition

Swenson’s class IV partially Swenson’s class V partially edentulous condition edentulous condition

The first system to receive recognition from the profession was one proposed by Cummer in 1920. His classification based upon the choice of natural teeth for direct retainers

Class I – a partially edentulous arch in which two diagonally opposite teeth are chosen as abutment teeth

Class II

- a partially edentulous arch in which two diametrically opposite tooth are chosen as abutment teeth for the attachment of the direct retainers with an indirect retainer as an auxillary attachment.

Class III – a partially dentulous arch in which one or more teeth on the same side are chosen as abutment teeth for the attachment of the direct retainers with or without indirect retainer.

Class IV - a partially dentulous arch in which three or more teeth are chosen as abutment teeth for the attachment of direct retainers.

It is based on the relationship of the edentulous spaces to the abutment teeth.

Class I – Bilateral edentulous area located posterior to the remaining natural teeth.

Class II – Unilateral edentulous area located posterior to the remaining natural teeth.

Class III – Unilateral edentulous area with natural teeth remaining both anterior and posterior teeth

Class IV – A single but bilateral (Crossing the mid-line) edentulous area located anterior to the remaining natural teeth.

Class I maxillary archClass I maxillary arch Class II mandibular Class II mandibular

archarch

class III mandibular arch Class IV maxillary arch

Bailyn introduced a classification system based on whether the prosthesis is tooth- borne, tissue, or a combination of the two.

Class P I – Edentulous region posterior to the cuspid between two available abutments not more than three teeth distant from each other.

Class P II – Edentulous bilateral regions posterior to the cuspids with one available abutment tooth for each denture base area.

Class P III – edentulous region atleast three teeth posterior to the distal abutment.

Class A III – edentulous space anterior to the first bicuspid and between two teeth, more than three teeth distant from each other.

Class A I P II – Edentulous region anterior to the first bicuspid and between two available abutments less than three teeth distant from each other.

Class P I P II – both edentulous regions posterior to the cuspids: only one tooth available for anchorage, the other two separated by a distance of at least three teeth.

Class A I P III – has three edentulous spaces : One of these is anterior to the first bicuspid with two available anchor teeth separated by a distance of less than three teeth, another posterior to the cuspid with only one tooth for anchorage, third one posterior to the cuspid with two teeth available for abutments separated by less than three teeth

Class P1 Class PII

Class P III Class A III

Class A I P II Class P I P II

Class A I P III

A partial denture situatin falls under this classification when there are teeth posterior to all spans and when there are no more then four teeth missing in any space. A - Posterior teeth are missing and the anterior teeth are in place. B - Posterior teeth are missing, and some anterior teeth are missing C -Anterior teeth are missing and posterior teeth are in place. D-Anterior teeth are missing, and some posterior teeth are missing. These may be unilateral or bilateral spaces.

Neurohr’s Class II division 1Variation 1a partially edentulous

Condition

Neurohr’s Class II division 1Variation 1a partially edentulous

Condition

Neurohr’s Class II division 1Variation 1b partially edentulous

Condition

Neurohr’s Class II division 2Variation 1a partially edentulous

Condition

Mauk offered the profession a system of classification based on the

1)Number, length and position of the spaces and

2)The number and position of the remaining teeth

Class I – has bilateral spaces and teeth remaining in anterior segment.Class II – has bilateral posterior spaces and one or more teeth at the posterior end of the one space.Class III – bilateral posterior spaces and one or more teeth at the posterior end of both space.Class IV – unilateral posterior space with or without teeth at the posterior end of the space.Class V – Has anterior space onlyClass VI – Has irregular spaces around the arch.

Class I Class II

Class IIIClass IV

Class V Class VI

Godfrey described a system based on the location and extent of the edentulous spaces where teeth are to be replaced. A feature of Godfrey's system is that there are no subdivisions or modifications to the main classes.

Class A – has tooth borne denture bases in the anterior part of the mouth

Class B – has mucosa borne denture bases in the anterior of the mouth

Class C – has tooth borne denture bases in the posterior part of the mouth

Class D – has mucosa borne denture bases in the posterior part of mouth

Godfrey’s class A partially Godfrey’s class B partially edentulous condition edentulous condition

Godfrey’s class C partially Godfrey’s class D partially edentulous condition edentulous condition

Beckett proposed a system which, like the one suggested by Bailyn, is based on whether the denture base is tooth-borne, tissue-borne, or a combination of the two. The three basic classifications were:

Class 1- saddles (denture bases) which are tooth-borne;

Class 2, saddles (denture bases) which are mucosa-borne;

Class 3, inadequate abutments to support the saddle (denture base)

Friedman introduced a system in 1953 based on three essential segment types occurring either as discrete or as continuous segments. The letter A designates an anterior spaces (i.e., one or more of the six anterior teeth). The letter B designates a bounded posterior spaces. The letter C refers to a cantilever situation or a posterior free-end spaces.

Friedman’s type A partially Friedman’s type B partiallyedentulous condition edentulous condition

Friedman’s type C partiallyedentulous condition

The Austin-Lidge classification system in which the letter A is used to designate an anterior spaces of spaces, P designates posterior spaces, and Bi designates a bilateral conditions.

Class A1

Class A 1 – a missing anterior tooth on one side only.

Class A 2 – anterior teeth missing on both right and left sides.

Class P 1 – Posterior teeth are missing on one side only

Class P 2- Posterior teeth are missing on both right and left sides

Class A 1 P1 – anterior and posterior teeth are missing on one side only.

Austin and Lidge class A2 Austin and Lidge class P2Partially Edentulous condition Partially Edentulous condition

Austin and Lidge class AB1 Austin and lidge class PB1 Partially Edentulous condition Partially Edentulous condition

Skinners offered the profession a new and different classification in 1957. He noted that many removable partial denture classification in the past have been based on the number of teeth remaining, as exemplified by the work of Cummer.

Skinner’s class I partially Skinner’s class IV partially edentulous condition edentulous condition

Skinner’s class II partially Skinner’s class V partially edentulous condition edentulous condition

Applegate offers a system which is a modification of the Kennedy system.

Kennedy-Applegate’s class I Kennedy-Applegate’s class II partially edentulous condition partially edentulous condition

Kennedy-Applegate’s class IVpartially edentulous condition

Kennedy-Applegate’s class V

partially edentulous condition

ConclusionThe treatment plan of any edentulous region

depends on its classification which eventually decides the success of the prosthesis.

Though many systems of classifications are available, the most universally used one is the Applegate – Kennedy System for its simplicity.