PHYSIOLOGY OF TOOTH FORM FUNCTION
The teeth serve four main functions:
1. MASTICATION - Normal tooth form and proper alignment ensure efficiency in the incising and reduction of food
with the various tooth classes.
2. ESTHETICS - the form and alignment of the anterior teeth are important to a person’s physical appearance.
3. SPEECH - The form and alignment of anterior and posterior teeth assist in the articulation of certain sounds that
can have a significant effect on speech.
4. PROTECTION OF SUPPORTING TISSUES - the form and alignment of the teeth assist in sustaining the teeth in the
dental arches by assisting in the development and protection of the gingival tissues and alveolar bones that
support them.
CONTOURS
The degree of convexity of facial and lingual surfaces for protection and stimulation of the supporting
tissues during mastication.
Convexity generally, is located at the cervical third of the crown on the facial surfaces of all the teeth
and lingual surfaces of incisors and canines.
Too little contour may result in trauma in attachment apparatus. Under-contour of tooth may result in
irritation of soft tissue.
Over contouring is the worst offender, usually resulting in increased plaque retention that leads to a
chronic inflammatory state of the gingival.
Over-contour deflects food from gingiva and results in under-stimulation of supporting tissues.
Correct contour permits adequate stimulation for supporting tissue, resulting in healthy condition.
THE PROXIMAL HEIGHT OF CONTOUR SERVES TO PROVIDE:
1. Contacts with the proximal surfaces of adjacent tooth
2. Preventing food impaction
3. Adequate embrasure space apical to the contacts for gingival tissues, supporting bone, blood vessels, and nerves
that serve the supporting structures
PROXIMAL CONTACT AREA
Denotes the area of the proximal height of contour of the mesial or distal surface of the tooth that touches its
adjacent tooth in the same arch.
When teeth erupt to make proximal contact with previously erupted teeth, initially a contact point is present.
Improper contacts can result in food impaction between the teeth, producing periodontal disease, carious
lesions, and possible movement of the teeth.
Proximal contacts and interdigitation of the teeth through occlusal contacts stabilizes and maintains the integrity
of the dental arches.
EMBRASURE
V-shaped spaces that originate at the proximal contact areas between adjacent teeth.
Interdental papilla fills the embrasure.
The correct relationships of embrasures, cusps to sulci, marginal ridges, and grooves of adjacent and opposing
teeth provide for the escape of food from the occlusal surfaces during mastication
NOTES:
Col – is part of the interdental papilla located under the contact area of the posterior teeth. It has
nonkeratinized epithelium lining, prone to periodontal disease.
The teeth serve four main functions:
1. MASTICATION - Normal tooth form and proper alignment ensure efficiency in the incising and reduction of food
with the various tooth classes.
2. ESTHETICS - the form and alignment of the anterior teeth are important to a person’s physical appearance.
3. SPEECH - The form and alignment of anterior and posterior teeth assist in the articulation of certain sounds that
can have a significant effect on speech.
4. PROTECTION OF SUPPORTING TISSUES - the form and alignment of the teeth assist in sustaining the teeth in the
dental arches by assisting in the development and protection of the gingival tissues and alveolar bones that
support them.
CONTOURS
The degree of convexity of facial and lingual surfaces for protection and stimulation of the supporting
tissues during mastication.
Convexity generally, is located at the cervical third of the crown on the facial surfaces of all the teeth
and lingual surfaces of incisors and canines.
Too little contour may result in trauma in attachment apparatus. Under-contour of tooth may result in
irritation of soft tissue.
Over contouring is the worst offender, usually resulting in increased plaque retention that leads to a
chronic inflammatory state of the gingival.
Over-contour deflects food from gingiva and results in under-stimulation of supporting tissues.
Correct contour permits adequate stimulation for supporting tissue, resulting in healthy condition.
THE PROXIMAL HEIGHT OF CONTOUR SERVES TO PROVIDE:
1. Contacts with the proximal surfaces of adjacent tooth
2. Preventing food impaction
3. Adequate embrasure space apical to the contacts for gingival tissues, supporting bone, blood vessels, and nerves
that serve the supporting structures
PROXIMAL CONTACT AREA
Denotes the area of the proximal height of contour of the mesial or distal surface of the tooth that touches its
adjacent tooth in the same arch.
When teeth erupt to make proximal contact with previously erupted teeth, initially a contact point is present.
Improper contacts can result in food impaction between the teeth, producing periodontal disease, carious
lesions, and possible movement of the teeth.
Proximal contacts and interdigitation of the teeth through occlusal contacts stabilizes and maintains the integrity
of the dental arches.
EMBRASURE
V-shaped spaces that originate at the proximal contact areas between adjacent teeth.
Interdental papilla fills the embrasure.
The correct relationships of embrasures, cusps to sulci, marginal ridges, and grooves of adjacent and opposing
teeth provide for the escape of food from the occlusal surfaces during mastication
NOTES:
Col – is part of the interdental papilla located under the contact area of the posterior teeth. It has
nonkeratinized epithelium lining, prone to periodontal disease.
