Untitled

• Beading


  • All maxillary major connectors should display minor elevations at those borders that contact the palatal soft tissues
  • The elevations are termed bead lines and are intended to slightly displace the adjacent soft tissues
• Bead lines


  Elevations created by carving shallow channels on the surface of a maxillary master cast before duplication in investment material
• Creating bead lines


  1. Carve shallow channels 0.5 to 1.0 mm wide and deep on the surface of a maxillary master cast

  2. Use a small spoon excavator or round bur rotating at slow speed

  3. Reduce the depth of the beading in areas of thin tissue coverage such as the midpalatine raphe or a palatal torus
• Relief should not be used under a maxillary major connector except in the presence of a palatal torus or a prominent median suture line
• The intimate contact between the palatal soft tissues and the metal connector enhances the retention and stability of the denture
• Types of Maxillary Major Connectors

  • Single palatal bar
  • Single palatal Strap
  • Anterior-posterior palatal bars
  • Anterior and posterior palatal Strap-type connector
  • Palatal plate-type connector
  • Horseshoe (U-shaped palatal connector)
• Single palatal bar


  • Narrow half oval with thickest point at the center
  • Limited to short-span Class II applications replacing one or two teeth on each side of the arch
  • Should not be placed anterior to the second premolar position to avoid discomfort and altered speech
• Single palatal strap


  Wide band of metal with a thin cross sectional dimension, at least 8 mm in anteroposterior dimension
• Single palatal strap


  • Offers great resistance to bending and twisting forces due to its location in two or more planes
  • Relatively thin design offers little interference with normal tongue action, so well accepted by patients
  • Increased tissue coverage helps distribute applied stresses over a larger area
• Papillary hyperplasia


  Condition seen when the partial denture is worn 24 hours a day, usually accompanied by poor oral hygiene

  
• Anterior and posterior palatal bar-type connector


  • Anterior bar is relatively flat with strap-like cross-section, positioned on slopes of prominent rugae
  • Posterior bar is half oval, similar to palatal bar
  • The two bars are joined by flat longitudinal elements on each side, creating a rigid L-beam effect
• Anterior and posterior palatal strap-type connector


  • Provides maximum rigidity and minimum bulk, may be used in almost any maxillary partial denture design
  • Each strap should be at least 8 mm in width and relatively thin in cross section
  • Borders should be kept 6 mm from free gingival margins or extend onto lingual surfaces of remaining teeth
• Anterior and posterior palatal strap-type connector


  • Anterior strap should be in the farthest posterior position possible to promote comfort and minimize interference with speech
  • Posterior strap should be flat, minimum 8 mm wide, located as far posterior as possible but anterior to the junction of hard and soft palates
• Palatal plate-type connector


  Complete palate provides the ultimate rigidity and support, as well as the greatest amount of tissue coverage
• The anterior border of a complete palate must be kept 6 mm from the marginal gingivae, or it must cover the cingula of the anterior teeth
• Border of palatal strap


  • Located at junction of hard and soft palates
  • At right angles to median palatal suture
  • Extended to hamular notch area(s) on distal extension side(s)
• Anterior palatal strap


  • Anterior border not placed farther anteriorly than anterior rests and never closer than 6 mm to lingual gingival crevices
  • Follows the valleys of the rugae at right angles to the median palatal suture
  • Posterior border, if in rugae area, follows valleys of rugae at right angles to the median palatal suture
• Palatal plate-type connector


  The complete palate provides the ultimate rigidity and support. It also provides the greatest amount of tissue coverage.
• When to use palatal plate-type connector


  • When maximum tissue support is required
  • In long distal extension cases or where six or less anterior teeth remain
  • Where the primary abutments are periodontally involved, requiring maximum stress distribution
  • Where the edentulous areas are covered with flabby tissue or where there is a shallow palatal vault
  • Usually not used in the presence of torus palatinus
• Palatal plate


  Any thin, broad, contoured palatal coverage used as a maxillary major connector and covering one half or more of the hard palate
• Uses of palatal plate


  • As a plate of varying width that covers the area between two or more edentulous areas
  • As an anterior palatal connector with a provision for extending an acrylic resin denture base in a posterior direction
• Palatal plate location


  • Should be located anterior to the posterior palatal seal area
• Horseshoe (U-shaped palatal connector)


  Thin band of metal running along the lingual surfaces of the remaining teeth and extending onto the palatal tissues for 6 to 8 mm
• To avoid the tendency to flex, the metal crossing the anterior palate must be thicker than that used in most other major connectors
• The U-shaped palatal connector should never be used arbitrarily and may be indicated when a large inoperable palatal torus exists, and occasionally when several anterior teeth are to be replaced
• Principal objections to use of the U-shaped connector


  • Lack of rigidity can allow lateral flexure under occlusal forces, inducing torque or direct lateral force to abutment teeth
  • Doesn't provide good support and may impinge underlying tissue when subjected to occlusal loading
  • Increase in thickness, at the rugae area, to enhance rigidity may interfere with the freedom of the tongue
• A U-shaped major connector may be made more rigid with multiple teeth supported rests and a wider coverage of the major connector
• Review of indications for maxillary major connectors


  • The combination anterior-posterior connector design may be used with any Kennedy class, most frequently in Classes II and IV
  • The single palatal strap is used more frequently in Class III situations
  • If the periodontal support of the remaining teeth is weak, more of the palate should be covered
  • The palatal plate type or complete coverage connector is used most frequently in Class I situations
  • When anterior teeth must be replaced, an anteroposterior palatal strap, complete palate, or horseshoe major connector may be used
  • If a torus is present and is not to be removed, an anteroposterior palatal strap, or horseshoe major connector may be used