An overview of treatment planning based on Kennedy classifications

Planning criteria for Kennedy Class I

  • Bilateral planning: Bilateral distal extension abutments (rotation around diametric or diagonal fulcrum axis)
  • Mesio-occlusal rests
  • In anterior modifications, consider fixed partial denture (bridge) option (within the limitations of Ante’s law)
  • Bilateral flexible clasp assemblies
  • No additional clasps in anterior modifications
  • Indirect retainers in the bilateral anterior region: mesial arch stabilization
  • Short guiding planes
  • Maximally extended denture bases and functional impression for tissue support
  • More rigid major connector required for distal extension denture base movement
  • Bilateral balanced occlusion (especially in maxillary Class I cases with long edentulous spans)

 

Planning criteria for Kennedy Class II

  • Bilateral planning: Terminal abutments on the distal extension side and on the most posterior molar of the opposing arch (rotation around a diagonal fulcrum axis)
  • Unilateral planning is only applicable in cases limited to the use of a precision attachment
  • In anterior modifications, consider the option of a fixed partial denture (bridge) option (within the limitations of Ante’s law)
  • In posterior modifications, utilize the advantages of direct and indirect retainers without resorting to a bridge
  • When a posterior modification is present, triangular support and retention can be achieved with an additional (secondary) abutment anterior to the modification; however, due to the presence of a distal extension base, rotation still occurs around a diagonal fulcrum axis despite three-point support with three abutment teeth
  • On the distal extension side: mesio-occlusal rest; on the opposing arch, additional rest support
  • On the distal extension side, flexible clasp on the primary abutment; on the opposing arch, circumferential clasp on the most posterior abutment
  • In posterior modifications, on the abutment anterior to the modification space: flexible clasp
  • Indirect retainer on the opposing arch: cross-arch stabilization
  • Utilize the posterior modification space as an indirect retainer
  • Short guiding planes
  • Maximally extended denture base and functional impression for tissue support
  • Rigid major connector
  • Unilateral balanced occlusion, group function, or canine-guided occlusion, depending on the length of the edentulous span

 

Planning criteria for Kennedy Class III

  • Bilateral planning: Terminal (primary) abutments form a triangular or quadrangular support plane (in posterior modifications), with no rotation for denture base/s
  • Rests placed on surfaces adjacent to the edentulous space
  • Triangular or quadrangular configuration, commonly planned with rigid circumferential clasp assemblies
  • No need for indirect retainers
  • In anterior modifications, consider a fixed partial denture option (within the limitations of Ante’s law)
  • Extended and multiple guiding planes contribute to retention and help eliminate clasps from esthetic zones
  • No need for tissue support or functional impression
  • Rigid but simplified and comfortable major connector
  • Preserve the patient’s existing occlusal scheme (canine guidance or group function)

Planning criteria for Kennedy Class IV

  • Two terminal abutments adjacent to the anterior edentulous span and additional bilateral abutments at the most posterior region of the dental arch
  • Disto-occlusal rests on the anterior terminal abutments; bilateral embrasure rests on the posterior abutments
  • Diametric or diagonal fulcrum axis (passing through the anterior abutments)
  • Quadrangular clasp design or preferably only embrasure circumferential clasps on posterior abutments
  • Elimination of anterior clasps by using bilateral short guiding planes
  • Bilateral indirect retainers in the posterior region: distal arch stabilization
  • Maximally extended denture base and functional impression for tissue support (especially in long-span edentulous areas)
  • Rigid major connector
  • Adjusted tooth arrangement (with no labial denture base flange) when no vertical or horizontal advanced resorption is present or presence of bony undercuts
  • In occlusion: passive contact with opposing anterior natural teeth, with no contact during eccentric movements

 

 

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A Guide to Removable Partial Denture Planning Copyright © 2025 by Funda Akaltan. All Rights Reserved.

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