Posterior Teeth Arrangement for Dentures

Tooth Arrangement (Posterior)

• The presentation is about arranging posterior teeth for dentures.
• Dr. Malak Bamigdad, BDS KAU, a Saudi Board-certified prosthodontist, is the presenter.
• The presentation covers general considerations for arranging posterior teeth (mandibular and maxillary).
• Factors affecting balanced occlusion include condylar guidance, compensating curve, incisal guidance, cuspal inclination, and planes of occlusion.

General Considerations for Posterior Tooth Arrangement

• The vertical overlap of anterior teeth is sometimes adjusted for aesthetics, phonetics, or function.
• When anteroposterior space is insufficient, a premolar might be removed.
• Non-balanced occlusion involves aligning mandibular posterior teeth on a flat occlusal plane. The long axes of these teeth should be perpendicular to the occlusal plane.
• Balanced occlusion requires that the posterior teeth be arranged along a compensating curve.

Teeth Arrangement Order

• The presentation includes illustrative examples of different denture arrangements.
• Images displayed visually guide the arrangement of teeth.

General Considerations for Arrangement of Posterior Teeth

• Arrangement is done to address vertical overlap of anterior teeth in cases involving esthetics, phonetics and/or function.
• Consideration needs to be given to insufficient anteroposterior spacing which may necessitate the elimination of a premolar tooth for better chewing.
• Non-balanced occlusions require the mandibular posterior teeth to be arranged on a flat occlusal plane with tooth axes perpendicular to the plane.
• The presentation notes the need for a compensating curve for balanced occlusion in posterior tooth arrangement.

Lingualized Occlusion

• Lingualized occlusion means that any buccal cusp contacts in the maxilla should be absent in centric relation and side-to-side movements.

Factors Affecting Balanced Occlusion

• Factors affecting balanced occlusion include condylar guidance, the compensating curve, incisal guidance, cuspal inclination, and the plane of occlusion.

Compensating Curves

• Artificial curves are applied to the complete denture occlusion for achieving a balanced occlusion.
• These curves are amongst the most important determinants of occlusal balance.
• Anteroposterior and medio-lateral curves are key components of the compensating curves.

Mandibular Posterior Tooth Arrangement

• The distal surfaces of canines are the most anterior positions for placing first premolars.
• The distal limit for mandibular molars is the beginning of the retromolar pad incline.
• Premolars should be arranged with the buccal surface of the first premolar aligning with that of the canine.
• The central groove of the first premolar should align with the contact point or tip of the canine. The second molar should directly rest on the remaining ridges.

Maxillary Posterior Teeth

• For lingualized occlusions, the buccal cusps of the opposing teeth should be approximately 0.5 millimeters above the antagonist teeth in the maxillary teeth when the articulator is moved into the working position.

Conventional Balanced Occlusion

• A balanced occlusion means the opposing surfaces will be close but not touching in centric relation to each other.
• Anterior and bilateral cross-arch contacts should exist in all excursive movements and cross-tooth contact on the working side should be present.

Maxillary Posterior Teeth Arrangement

• Maxillary posterior teeth (particularly second molars) must be arranged to prevent cheek biting.
• The lingual cusps of the maxillary teeth should be centered on the grooves and ridges of the mandibular teeth. The maxillary buccal surfaces are placed more buccally compared to the mandibular counterparts.
• Creating a reverse articulation (crossbite) is sometimes necessary for posterior teeth to compensate for bone resorption.

Occlusal Plane

• The occlusal plane is usually located at the mid-to-upper third portion of the retromolar pad.
• It should be midway between the maxillary and mandibular residual ridges and parallel to both.

Vertical Height of Occlusal Plane

• Modifying the occlusal plane's vertical height is sometimes needed for a lack of interocclusal clearance.
• Lowering the plane decreases the height of the teeth above mandibular ridges, reduces cantilever forces, improving mandibular stability.

Balanced Occlusion

• A balanced occlusion shows bilateral posterior tooth contacts, and simultaneous anterior contacts during all excursive movements.