Dental Anatomy: Tooth Morphology

Study Notes

Human Dentition

Human teeth are equally arranged into four quadrants: upper right, upper left, lower right, and lower left.
Each quadrant has a specific arrangement of teeth: incisors, canines, premolars, and molars.

Tooth Morphology

Incisors:
- Have a trapezoidal shape with the longer parallel side at the incisal edge and the shorter side at the cementoenamel junction.
- Labial and lingual crest of curvatures are at the cervical third of the crown.
- Newly erupted incisors have rounded portions on the incisal ridge called "Mamelons".
Canines:
- Have a cone or wedge shape, suitable for piercing, cutting, and tearing.
- Are designed to function as holding or grasping teeth.
Premolars (Bicuspids):
- Have a wider surface with multiple projections (cusps), suitable for grinding food.
- The fourth tooth from the midline is the First Premolar, and the fifth tooth is the Second Premolar.
Molars:
- Have a wide surface with multiple projections (cusps), suitable for grinding food.
- Are characterized by having multiple cusps.

Tooth Development

Developmental Lobes:
- Are the first growth centers of the tooth, which fuse to form the tooth.
- Each tooth begins its development from four or more growth centers.
Developmental Grooves:
- Are the lines that mark the fusion of the developmental lobes.
- Can be seen on the tooth after its eruption but soon disappear due to wear and attrition.

Tooth Structure

Pulp Chamber:
- Is wider from the mesio-distal section, confirming the shape of the crown.
- Tapers from the incisal part, but is wider at the cervix.
- Has three pulp horns corresponding to the three mamelons.
Root Canal:
- Tapers towards the apex.
- Has a roughly triangular shape in young teeth, becoming rounded or crescent-shaped in old teeth.
Cervical Line:
- Is less curved than that of the central incisor.
- Is perfectly centered.

Other Terms

Inclined Planes:
- Are slopes from cusp tips to the developmental grooves.
Height of Contour:
- Is the point of maximum convexity of the tooth surface.
Pits:
- Are small pinpoint depressions located at the junction of developmental grooves and/or at their terminals.

Description

This quiz covers the fundamental concepts of tooth morphology, including the arrangement of permanent and deciduous teeth, and the lingual surface of teeth. Based on the book 'Fundamentals of Tooth Morphology and Physiology'.