Wilkins Chapter 16: Hard Tissue Examination of the Dentition

Course Objectives

• Identify three divisions of human dentition.
• Explain developmental and non-carious lesions.
• Describe dental injuries and tooth fractures.
• List classifications of dental carious lesions.
• Explain early childhood caries development.
• Understand dental charting factors.
• Explain principles and classification of occlusion.
• Discuss functional and parafunctional contacts.
• Understand occlusal trauma.
• Briefly discuss study models.

Divisions of Human Dentition

Primary Dentition

• Begins in utero with mineralization.
• Exfoliated as permanent teeth erupt.
• Identified using letters.

Mixed Dentition

• Transition from primary to permanent teeth.
• Occurs approximately from ages 6 to 12.

Permanent Dentition

• Mineralization starts at birth and continues into adolescence.
• Roots complete around three years after eruption.

Clinical Crown and Root

• Clinical Crown: Visible part of the tooth, above the periodontal tissues.
• Clinical Root: Not visible, attached to periodontal fibers.
• Anatomical Crown: Covered by enamel.
• Anatomical Root: Covered by cementum.

Hard Tissue Examination Procedure

Examination Components

• Teeth and existing restorations.
• Non-carious and carious lesions.
• Occlusion.

Dental Charting

• Identify missing, supernumerary, and unerupted teeth.
• Document existing restorations (composites, amalgams, crowns).
• Look for developmental enamel lesions.

Assessment of Dental Lesions

Examination Techniques

• Visual inspection with dental mirror.
• Use of air to dry teeth.
• Transillumination.

Radiographic Examination

• Review for carious lesions, anomalies, and fractures.

Clinical Examination

• Use of Shepherd's Hook Explorer for gentle exploration.
• Document with intraoral images.

Occlusion and Study Models

• Assess normal occlusion, malocclusion, and malpositions.
• Study models for occlusal relationships.

Developmental Enamel Lesions

Types and Causes

• Enamel Hypoplasia: Due to disturbance in enamel matrix formation.
• Hypomineralization: Occurs during mineralization, often due to disease or drug exposure.
• Hypomaturation: Fragile enamel from late mineralization.

Developmental Defects of Dentin

• Dentinogenesis Imperfecta: Genetic disorder leading to discolored, weak dentin.

Non-Carious Dental Lesions

Types

• Attrition: Due to tooth-to-tooth contact.
• Erosion: Chemical loss of tooth substance.
• Abrasion: Mechanical wear by external forces.
• Abfraction: Microfractures due to occlusal stress.

Tooth Fractures

Causes

• Accidents, sports, and falls.

Classification

• Enamel, crown, root, luxation, and avulsion types.

Dental Caries

WHO Definition

• Localized, post-eruptive pathologic process with cavity formation.
• Caries are preventable.

Classification

• Class I-VI: Based on location and tooth surfaces involved.

Stages

• Initial: Subsurface demineralization.
• Moderate: Enamel breakdown.
• Advanced: Cavitation into dentin.

Occlusion Classifications

Normal and Malocclusion

• Class I: Ideal relationship.
• Class II: Retrognathic profile.
• Class III: Prognathic profile.

Other Occlusal Deviations

• Crossbites, open bites, and overjet/underjet measurements.

Primary Teeth Occlusion

• Concepts of mesial step, flush terminal plane, and distal step.

Documentation in Dental Exams

• Note all existing conditions, lesions, occlusal habits, and previous orthodontic treatments.