Oral Anatomy and Histology Flashcards
ENAMEL
a hard protective tissue that covers the crown of the tooth.
* Location is the outer surface of the anatomical
crown
* Thickest at the tip of the crown and thinner at
cervical portion
* Color varies with thickness (Yellow-white or gray-
white)
* Hardest tooth tissue
* It is smooth (self-cleansing)
DENTIN
makes up the main bulk of the tooth. Dentin is
found in both the crown and root of the tooth.
* Main portion or body of the tooth
* Present in both the root and the crown
* Softer than enamel, harder than cementum or
bone
* Can continue to form throughout the lifespan of a
tooth
CEMENTUM
covers the root of the tooth
* Covers the root of the tooth
* Attaches the tooth to the bone
* Softer than enamel or dentin
* Light yellow in colour
PULP
soft connective tissue containing nerves and
blood vessels - in the center of the tooth.
* Center of the tooth, surrounded by dentin
* Nourishing and sensory (pain) function
* Composed of blood vessels, lymph vessels,
connective tissues, and nerve tissue
* Two parts of the pulp cavity
◦ pulp chamber and
◦ pulp canal
* The pulp horn is the extension of the chamber
Common Structures of a Tooth
-
Crown: the white part of tooth, covered with
enamel -
CEJ: the crown and root are joined at the
cemento-enamel junction (neck of tooth)
◦ The CEJ is also called the cervical line or the
cervix
*Root: part of the tooth covered in cementum,
embedded in the bone -
Apex: terminal end of the root.
◦ Apical foramen: tiny opening in the apex of the
root for blood vessels and nerves to enter
The Tooth Root
- All teeth have at least one and often more than
one root. - The root is covered by cementum and embedded
in the alveolar process. - Between the bone of the alveolar process and the cementum is the periodontal ligament, which
suspends the tooth and provides it with
nourishment. - Remember…the end of the root is called its apex;
the hole in the apex through which blood and
lymph vessels and nerves pass is called the apical
foramen - The term apical is used to describe something that has to do with the apex.
What’s the opposite of apical?
Structures associated with the tooth’s crown are
termed coronal.
Radicular
◦ having to do with the tooth root.
◦ the radicular pulp is the pulp contained in the
root
What teeth have a single root?
These are found in the anterior teeth and a few posterior teeth
Bifurcated Root
These divide into two seperate parts
This root is typically found on lower molars
Trifurcated Roots
- Means the division of a root into three separate parts
- This provides the tooth with maximum anchorage against biting force
- Typically upper molars where anchorage is essential
Incisors
- There are four incisors in each arch. Two central
incisors and two lateral incisors. - Location – the central incisors are side by side at
the midline. There is a lateral incisor on each side
of the central incisors. - Shape – single rooted, crowns are arched and
angle toward one sharp incisal edge. - Function – to cut or incise food with their thin
edges. Tongue side is shovel shaped
Cuspids (Canines)
- There are two cuspids in each arch. They are
sometimes referred to as canines. - Location – next to the lateral incisors, establishes
the corner of the arches. - Shape – anchored with the longest root, one
pointed cusp. - Function – used for holding, grasping, and tearing
food. Referred to as the cornerstone of the mouth
Premolars (bicuspids)
- There are four premolars in each arch. Two first
premolars and two second premolars. They are
sometimes referred to as bicuspids. - Location – first premolars are next to the cuspids
followed by the second premolars. - Shape – maxillary first premolars have a bifurcated root, all others have one root, one prominent cusp with one or two lesser lingual cusps.
- Function – holding food, like canines because they have cusps; also to grind food
