Geometric Shapes For Crown Profile Flashcards
What shape are all teeth when viewed from the facial AND lingual?
Trapezoid
What shape are all anterior teeth when viewed from the proximal?
Triangle
Benefits of trapezoidal shape (upside-down) of lingual and facial surfaces of all teeth
Interproximal space to accommodate interproximal tissue
Proximal contact
- protects interproximal tissue from trauma during mastication
- ensures respective positions of individual teeth within arch
Bone support around roots
Each tooth has two antagonists (except md centrals and mx third molars)
What shape are maxillary posterior teeth from the proximal view?
Trapezoid (short side = occlusal)
Benefits for maxillary posterior teeth to have trapezoidal (short side = occlusal) shape from proximal view
Constricted occlusal surface
Food more easily penetrated
Self cleansing action
Which teeth (from which views) are trapezoidal in shape?
Facial and lingual surfaces of all teeth
Proximal surfaces of maxillary posteriors
How many antagonists does each tooth have (with two exceptions)?
Two
Which teeth do not have 2 antagonists?
Mandibular centrals
Maxillary third molars
Benefits of triangular shape of anterior teeth from proximal view
Wide base to crown for strength
Narrow incisal ridge, facilitates penetration of food
Which teeth (from which views) are triangular in shape?
Proximal view of all anterior teeth
Which teeth (from which views) are rhomboidal in shape?
Proximal view of mandibular posteriors
What shape are mandibular posterior teeth from the proximal view?
Rhombiodal
Benefits of rhomboidal shape of mandibular posterior teeth from proximal view
Constricted occlusal surface in comparison with base
Inclines crowns lingual to root base, bringing the cusps into proper occlusion, keeping axes of crowns and roots of the teeth of both jaws parallel
