FROM UR SUPERMAN

Classification System for Complete Edentulism

Overview and Guidelines

  • The classification system serves to standardize the treatment of complete edentulism.

  • Patients with mixed diagnostic criteria should be categorized into the more complex classification if any single criterion falls into that class.

  • Use of a worksheet facilitates the analysis of diagnostic factors and aids in pre-treatment evaluation.

    • Reevaluation is advised after any preprosthetic surgery and can influence post-treatment classification.

  • Objective criteria enhance uniform utilization, improving communication among dental professionals.

  • It helps identify patients needing specialist treatment or advanced techniques.

  • Essential for research protocols evaluating different treatment procedures.

Goals of Prosthodontic Treatment

  • Aim to create a comfortable prosthesis that addresses both function and aesthetics for the patient.

  • Achieved by ensuring Class I jaw relation and occlusion.

Ridge Relationship

  • Defined as the positional relation of the mandibular ridge to the maxillary ridge.

Normal Relationship

  • In centric relation, the maxillary ridge is slightly anterior to the mandibular ridge in the anterior region.

  • Posteriorly forms an 80-degree angle to a horizontal plane; the mandibular ridge crest is slightly buccal to the maxillary ridge.

Ridge Resorption Patterns

  • Maxilla: Resorbed upward and inward (centripetal).

  • Mandible: Resorbed downward and outward (centrifugal).

Types of Classification

Skeletal Classification

  1. Class I: Most anterior point of the upper jaw aligned with or slightly anterior to the lower jaw (2 mm).

    • Present in approx. 55.5% of patients.

  2. Class II: Anterior point of the mandible retruded more than 2 mm from maxilla.

    • Present in approx. 10% of patients.

  3. Class III: Anterior point of the mandible protruded, with mandible forward to maxilla.

    • Present in approx. 34.5% of patients.

Dental Classification

  • Previous teeth positions affect aesthetics and force application from circumoral muscles and neutral zone position. Both classifications are crucial for effective complete denture fabrication.

Treatment Approaches

Class I Cases

  • Incisal and molar relations were achieved with few problems; ridge and supporting tissue factors may complicate treatment.

Class II Cases

  • High and low FMA (Skeletal): affects dentition and treatment principles based on Class I.

  • Extensive mandibular motion was noted.

  • Adjustments for maxillary protrusion include:

    1. Selecting narrower lower anterior teeth if protrusion is not extreme.

    2. Crowding lower anterior teeth for aesthetics.

    3. Leaving slight spaces between upper anterior teeth for canine relations.

    4. Grinding lower canine surfaces or eliminating lower first premolars as necessary.

Class III Cases

  • Characterized by lower anterior ridge being forward relative to maxillary ridge, from edge-to-edge to marked prognathism.

Management Strategies

  1. Edge-to-edge relation: Position teeth normally; no horizontal overlap.

  2. Extreme protrusion: Use negative horizontal labial overlap. Place lower anterior teeth labially to upper incisors.

  3. Size discrepancies: Adjust lower tooth molds or create acceptable overlapping of upper anterior teeth.

Arrangement of Artificial Teeth

Class II Jaw Relations

  • Difficult placement due to the wide upper arch. Management options include:

    1. Move upper posterior teeth palatal if discrepancy is slight.

    2. Use nonanatomical teeth for adaptability in placement.

    3. Interchanging upper and lower teeth if necessary, adjusting buccal contours for occlusion.

Class III Jaw Relations

  • In cases of mandibular protrusion, management strategies involve:

    1. Placing teeth edge-to-edge when ridges align.

    2. Managing extreme protrusion with a reverse overlap.

    3. Adjusting tooth sizes to fit widths appropriately.

Table 1: Checklist for Classification of Complete Edentulism

Classification Breakdown

  • Class I: Bone Height >21 mm, Type A morphology, adequate muscle attachments.

  • Class II: Bone Height 16-20 mm, Type B morphology, some muscle attachment issues.

  • Class III: Bone Height 11-15 mm, Type C morphology, further attachment problems.

  • Class IV: Bone Height <10 mm, Type D morphology, significant attachment issues.

Additional Conditions

  • Conditions requiring preprosthetic surgery categorized by severity.

  • Tongue anatomy assessed for its impact on interarch space and denture fit.

  • Psychological and systemic disease factors considered as modifiers in treatment.