When designing partial dentures, one of the most commonly used classification systems is the Kennedy Classification. This was developed by Dr Edward Kennedy in the 1920s. The classification is ranked based on the most commonly found partially dentate situations.
Kennedy Class I
Kennedy Class I describes a patient who has BILATERAL free-end saddles, i.e. they have edentulous posterior areas bilaterally. This is the most comment classification. There are no further posterior teeth to the edentulous area. A free-end saddle is where the saddle is not resting on teeth on both sides (i.e. is lacking an abutment tooth).
Kennedy Class II
This describes a patient who has a UNILATERAL free-end saddle, i.e. they have a one-sided, posterior edentulous area. They have no further teeth behind the edentulous area. As the image below shows, it is like a Class I but just covering one side of the arch.
Kennedy Class III
This describes a patient who has a UNILATERAL BOUNDED POSTERIOR saddle. This means that the edentulous area has teeth located both anteriorly and posteriorly to it, as shown in the image below. As they do not possess free-end saddles, they tend to be far more secure cases when designing.
Kennedy Class IV
This describes a patient with a SINGLE, ANTERIOR BOUNDED saddle. This is the rarest of the classifications.
This refers to multiple edentulous areas present in a case. Modifications can only apply to Kennedy Classes I, II and III. This is because a Kennedy Class IV case with modifications would fall in to one of the other classifications, as these take priorities. Examples:
- Class I – posterior, bilateral free-end saddles
- Class II – posterior, unilateral free-end saddle
- Class III – posterior, unilateral bounded saddle
- Class IV – anterior bounded saddle
- Class I, II and III can have modifications.