Arrangement of Artificial Teeth

Arrangement of Artificial Teeth

• Factors considered include bone resorption patterns, aesthetics, occlusal plane harmony with tooth contours, and interdigitation of teeth.

Factors Considered in Tooth Arrangement

• Bone Resorption Pattern:

  • Maxilla resorbs upward and inward, becoming smaller.
  • Mandible inclines outward, becoming wider.
  • This change can create a prognathic appearance.
  • Upper anterior teeth should be placed labially to the crest of the ridge to maintain the original position.

• Aesthetics:

  • Masculine characteristics are expressed by cuboidal, muscular forms and strong tooth contours.
  • Feminine characteristics are expressed by roundness, smoothness, and soft lines.

• Occlusal Plane:

  • Vertical distance between ridges is crucial.
  • The length of maxillary anterior teeth should be determined based on the lips position when smiling.
  • Maintaining appropriate high lip line is important to avoid compromising aesthetics.
  • The distance between the tips of the canines should equal the width of the nose base.
  • The width of the upper centrals should match the width of the philtrum.

• Harmony of Teeth with Contour:

  • Residual ridges should be positioned considering resorption patterns.
  • Arch forms (square, tapering, ovoid) should be chosen matching the natural form.

• Interdigitation of Teeth:

  • This aspect ensures proper fitting and stability of the artificial teeth.

Setting of Teeth

• Landmarks are crucial for precise placement:
  • Mark corners of the mouth on wax occlusal rims.
  • Lines are drawn from the lateral surface of the alae nasi to the maxillary occlusal rim.
  • A line is drawn perpendicular to the palate midline through the distal border of the incisive papilla.

Central Incisor

• Long axis: Parallel to patient facial long axis (midline of face).
• Labial contour: Blends with facial contour.
• Rotation on long axis: Varies based on arch form.

Maxillary Lateral Incisor

• Angle: Set at a 5° angle to the perpendicular.
• Incisal edge: Approximately 1mm short of the horizontal plane.
• Labial surface: Slightly inside at the cervical end.
• Distal half: Slightly rotated lingually.

Other Considerations

• The long axis slopes toward the midline when viewed from the front, and the incisal edge is 1 mm short of the occlusal plane.

• Slopes labially by 20 degrees when viewed from the side.

• The canine is the arch's turning point; its mesial half matches anterior teeth, and the distal half aligns with posterior teeth.

• The cusp is in contact with the occlusal plane.

• The long axis is parallel to the vertical axis, and the cusp is in contact with the horizontal plane.

• Teeth align with the contour of the lower lip.

• Incorrect positioning negatively affects aesthetics.

• Facial surface of the central incisor is perpendicular to the occlusal plane.

• Lateral incisor's neck is slightly depressed.

• Canine's neck is more prominent.

• Classes II and III cases have specialized setup procedures regarding tooth placement, vertical overlaps, and support modiolus.

• Posterior teeth are set inside the ridge to occlude with lower teeth for stability.

• Upper premolars have flattened lingual cusps that occlude with flattened lower premolars in class II settings.

• Class III cases might require negative or reversed horizontal overlap, and altered premolar positioning to accommodate the differing ridge relations

• Buccal corridor assessment is part of the evaluation to ensure sufficient space and aesthetics.

This quiz covers the essential factors involved in the arrangement of artificial teeth, focusing on bone resorption patterns, aesthetics, and occlusal plane considerations. Understanding these aspects is crucial for successful denture fitting and ensuring patient satisfaction.