Complete Denture Anatomy Quiz

Complete Denture Anatomy

• The edentulous ridge in the maxilla and mandible are important for designing complete dentures.
• The objective of a complete denture is to restore lost teeth and their surrounding structures functionally, anatomically, and aesthetically without damaging supporting structures.
• Edentulous jaw landmarks are classified as limiting structures, supporting structures, and relief areas.

Limiting Structures Maxilla

• Labial & Buccal Frenum: Fibrous bands covered by mucous membrane.
  • Labial Frenum: Extends from the labial aspect of the residual ridge to the lip. A passive frenum without active muscle fibers. Requires a v-shaped notch (labial notch) that is narrow but deep enough to avoid interference.
  • Buccal Frenum: Attached to the levator anguli oris, orbicularis oris, and buccinator muscles. Requires greater clearance on the buccal flange (shallower and wider) than the labial frenum.
• Labial & Buccal Vestibule (Sulcus): The labial sulcus is bounded by teeth, gingiva, the residual alveolar ridge, and the lips. It extends from one side of the buccal frenum to the other, divided into left and right compartments by the labial frenum. The buccal sulcus extends from the buccal frenum anteriorly to the hamular notch posteriorly. Its size depends on the contraction of the buccinator muscle.
• Posterior Palatal Seal Area (Post-Dam): Aids in retention, prevents food accumulation, compensates for polymerization shrinkage, and reduces gag reflexes by preventing gaps between the denture base and soft palate during movement.
  • The distal end of the denture must cover the tuberosities, extend into the hamular notches, and end 1-2mm posterior to the vibrating line.

Supporting Structures Maxilla

• Primary Stress-Bearing Areas: Posterior part of the palate, posterolateral part of the residual alveolar ridge.
• Secondary Stress-Bearing Areas: Palatal rugae area, maxillary tuberosity.

Relief Areas Maxilla

• Incisive Papilla: Midline structure behind the central incisors. Exit point for the nasopalatine nerves and vessels. Requires relief to avoid nerve compression, necrosis in the distribution area, and anterior palate paresthesia.
• Mid-Palatine Raphe: Extends from the incisive papilla to the distal end of the hard palate. Divided into three parts:
  • Anterior Part: From lingual frenum to the mylohyoid ridge, the shallowest part of the lingual flange.
  • Middle Region: From the premylohyoid fossa to the distal end of the mylohyoid region.
  • Posterior Portion: From the end of the mylohyoid ridge to the retromylohyoid curtain. Provides a valuable undercut area for retention. Overextension causes soreness and instability.

Limiting Structures Mandible

• Alveololingual Sulcus:
  • Anterior Part: From the lingual frenum to the mylohyoid ridge (shallowest portion of the lingual flange)
  • Middle Region: From the premylohyoid fossa to the distal end of the mylohyoid region.
  • Posterior Portion: From the end of the mylohyoid ridge to the retromylohyoid curtain.
• Retromolar Pad: Pear-shaped triangular soft pad of tissue at the distal end of the lower ridge. Forms the posterior seal of the mandibular denture. The denture base should extend to 2/3 of the retromolar pad triangle.
• Pterygomandibular Raphe: A ligamentous band of the buccopharyngeal fascia attached superiorly to the pterygoid hamulus of the medial pterygoid plate and inferiorly to the posterior end of the mylohyoid line of the mandible.

Supporting Structures Mandible

• Primary Stress-Bearing Area: Buccal shelf area
• Secondary Stress-Bearing Area: Residual alveolar ridge

Relief Areas Mandible

• Mylohyoid Ridge: Attachment for the mylohyoid muscle. Lies along the lingual surface of the mandible. Located close to the inferior border of the mandible anteriorly and near the residual ridge posteriorly. Covered by thin mucosa; requires relief to prevent trauma. The lingual flange should extend past the mylohyoid ridge but not into the undercut.
• Mental Foramen: Lies on the external surface of the mandible between the 1st and 2nd premolar region.
• Genial Tubercle: A small protuberance located on the lingual aspect of the mandible, above the mylohyoid ridge.
• Torus Mandibularis: A bony growth on the lingual aspect of the mandible, usually in the premolar region. Requires relief.

Test your knowledge on complete denture anatomy with this quiz. Learn about the important structures of the edentulous ridge in the maxilla and mandible, as well as the classification of jaw landmarks. Enhance your understanding of designing complete dentures for optimal function and aesthetics.