Even though recent reports have shown a consistent decline in the prevalence of tooth loss during the past few decades, significant variation in tooth loss distribution remains. It would be most helpful to consider which combinations of tooth loss are most common and to classify these for the purpose of assisting our management of partially edentulous patients. Several classifications of partially edentulous arches have been proposed and are in use. This variety has led to some confusion and disagreement concerning which classification best describes all possible configurations and should be adopted.

The most familiar classifications are those originally proposed by Kennedy, Cummer, and Bailyn. Beckett, Godfrey, Swenson, Friedman, Wilson, Skinner, Applegate, Avant, Miller, and others have also proposed classifications. It is evident that an attempt should be made to combine the best features of all classifications so that a universal classification can be adopted.

A classification that is based on diagnostic criteria has been proposed recently for partial edentulism.¹ The purpose of this system of classification is to facilitate treatment decisions on the basis of treatment complexity. Complexity is determined from four broad diagnostic categories that include location and extent of the edentulous areas, condition of the abutments, occlusal characteristics and requirements, and residual ridge characteristics. The advantage of this classification system over those in standard use has yet to be documented.

Today, the Kennedy method is probably the most widely accepted classification of partially edentulous arches. In an attempt to simplify the problem and encourage more universal use of a classification, and in the interest of adequate communication, the Kennedy classification will be used in this textbook. The student can refer to the “Selected Reading Resources” section for information relative to other classifications.

Although classifications are actually descriptive of the partially edentulous arches, the removable partial denture that restores a particular class of arch is described as a denture of that class. For example, we speak of a Class III or Class I removable partial denture. It is simpler to say “a Class II partial denture” than it is to say “a partial denture restoring a Class II partially edentulous arch.”