Physiologic Form of Teeth and Periodontium

Flashcards about the physiological form of teeth and periodontium, covering topics such as proximal contact relation, interproximal spaces, embrasures, facial and lingual contours, curvature of the cervical line, crown and root form, angulation, and self-cleansing ability.

Physiologic Form of Teeth

Form of teeth is consistent with the function they perform, their position, and arrangement in structures involved in mastication.

Proximal Contact Relation

Newly erupted tooth has tight proximal contact; later develops into a contact area due to wear and attrition.

Significance of Proper Proximal Contact Area

Prevent food compaction, protect interdental gingiva, distribute masticatory forces, and provide stability by combining anchorage of all teeth.

Consequences of Abnormal Proximal Contact Relation

Lead to gingival recession and alveolar bone loss due to mesial drifting and loss of supporting structures.

Interproximal Spaces

Triangular shaped spaces found between the teeth, cervical to the contact area.

Significances of Interproximal Spaces

Provide spaces for interdental gingiva, alveolar bone, and prevent food impaction.

Embrasure (Spillway)

Open space between two adjacent teeth, always incisal/occlusal to the contact areas; triangular in shape.

Significances of Embrasures

Spillway for food, decreases occlusal forces, makes teeth self-cleansing, and protects gingival tissues.

Facial & Lingual Contour in Anterior Teeth

Height of contour on both labial and lingual sides is in the cervical 1/3.

Facial & Lingual Contour in Posterior Teeth

Height of contour on the buccal surface is in the cervical 1/3; lingual surface is in the middle 1/3.

Significance of the Contour/Curvatures

Hold gingiva under tension, deflect food away from gingival margin, and deflect food over the gingiva to massage it.

Significance of Curvature of the Cervical Line

Site of attachment for the gingiva to tooth via the epithelium of the dentogingival junction.

Significance of Proximal Contour of the Crown

Responsible for the development and design of the embrasure, interproximal space and proximal contact.

Root Form

Length, number, distribution & outlines. They are the foundation of the tooth and responsible for the transmission of occlusal forces to the jaw.

Length & Number of Roots

Teeth have single root if they do little work; root remains single but long to pierce and tear tough food.

Root Outline

Facially, it is a cone shape; provides interdental space for alveolar bone and holds gingiva in the normal level.

Lingual Inclination of Crown of Lower Posterior Teeth

Crown is not angulated lingually to the root of the same teeth but also to the crown of the opposing tooth when both come in centric occlusion.

Distal Angulation of Crown & Root of Permanent Molars

Distal angulation of the crown is due to the progressive tilt of the occlusal surface toward the mesiodistal direction.

Self-Cleansing Ability of the Tooth

Achieved by proper form of teeth with smooth rounded surfaces/geometric outlines and proper alignment of the teeth in dental arches.