Oral Structures Flashcards
Function of Oral Cavity
- Gateway to digestive system
- Speech
Secondary Functions:
Respiration, Defense
Spaces
- Vestibule
- Oral Cavity Proper
- Pharynx
Characteristics of External Surface
- Keratinized Stratified Squamous Epithelium (skin)
2. Hair and Sweat Glads
Characteristics of Vermillion Zone (red area of lips)
- Transition between keratinized and non-keratinized
- Abundant dermal capillaries (red)
- No hair or sweat glands
Characteristics of Internal Surface
- Typical oral mucosa
2. Mucosa tethered to underlying muscle at intervals in many folds
Number of permanent Teeth
32 permanent teeth and 8 within each dental quadrant
Incisors
8 teeth for cutting, single root
Canine
4 teeth for grasping, single root
Premolars
8 for grinding, two roots
Molars
12 for grinding, 2/3 roots
Permanent teeth are preceded by…
20 deciduous (baby) teeth– No deciduous precursors for the molars
2 Main Regions of Tooth Structure
A. Crown (exposed)
B. Root (in socket)
(both meet at neck)
What is Enamel
99% calcium crystals
-Hardest substance in body
What is Dentin
Bulk of the tooth (bone-like but harder than bone, with collagen and mineral)
-Pulp cavity with vessels and nerves
What is the Root Canal
The part of the pulp in the root
Define Cementum
Bone layer of tooth root
-Attaches tooth to periodontal ligament
What is Periodontal Ligament?
- Anchors tooth in boney socket of the jaw
- Continuous with gingiva (gums)
Plaque
Film of sugar, bacteria and debris
Structure of the Tooth
(PIC)
Crown is covered by enamel and root is covered by cementum which meet at the neck. The Peridontal Ligament binds the cementum to spongy bone. Odontoblasts give rise to dentin which surrounds the pulp cavity contianing blood vessels and nerves which exit via the root canal
What is Enamel
The hardest component of the human body and the richest in calcium (95% calcium salts called Hydroxyapatite)
What does Ameloblast produce?
Enamel
Enamel Rods
Hydroxyapatite crystals form long, tightly packed enamel rods that extend the full thickness of the enamel
Can the Enamel part of the tooth repair itself?
No, Ameloblasts degenerate during tooth eruption
What is Hydroxypatite
95% calcium salts