Oral Anatomy & Histology (Review: Outcome 1) Flashcards
Anatomy
The study of the human body’s shape and structure
Nomenclature
System of name in science
Anatomical position
- Standing erect (upright)
- Toes pointed forward & feet flat on the floor
- Eyes directed to the horizon facing observer
- Arms by the sides with palms facing forward
Superior
ABOVE another part or closer to the head
- Ex. Nose is superior to the mouth
Inferior
BELOW another part, or closer to feet
- Ex. Heart is inferior to neck
Anterior
Toward the FRONT
- Ex. Heart is anterior to spine
Posterior
Toward the BACK
- Ex. Ear is posterior to nose
Medial
Toward the midline of the body
- Ex. Nose is medial to ears
Lateral
Away from midline of the body structure
- Ex. Ears are lateral to eyes
Proximal
CLOSE to a point of attachment or closer to trunk of body
- Ex. Elbow is proximal to wrist (close to should attachment)
Distal
FURTHER from a point of attachment or further from trunk of body
- Ex. Fingers are distal to wrist
Dorsal
On the back
- Ex. Spine is on dorsal side of body
Vertral
On the front
- Ex. Face is on ventral side of body
Planes (of the body)
Imaginary lines used to divide the body into sections
Midsagittal plane
VERTICAL plane that divides body into equal right and left halves
Parasagittal plane
ANY VERTICAL plane that does not pass through the midline of body & divides body into unequal right & left
Frontal/Coronal plane
Divides body into ANTERIOR & POSTERIOR portions
Horizontal/Transverse plane
Divides body into SUPERIOR & INFERIOR portions
Parts of Anterior Teeth
Central incisors, Lateral incisors, Canines (Cuspids)
Parts of Posterior Teeth
Premolars (Bicuspids), Molars
Make up of Permanent Dentition
Each arch has:
a. 4 permanent incisors (2 Central, 2 Lateral)
b. 2 permanent canines (cuspids)
c. 4 permanent premolars (bicuspids)
d. 6 permanent molars
How many permanent teeth in total?
32 teeth in a mouth
How many in permanent Maxillary and Mandibular arches?
Each have 16 teeth
How many permanent teeth in each quadrant?
8 teeth in each quadrant
a. 3 molars
b. 2 premolars (Bicuspids)
c. 1 canine (Cuspid)
d. 2 incisors (Central and Lateral)
How many primary teeth in each quadrant?
5 teeth in each quadrant
a. 2 molars
b. 1 canine (Cuspid)
c. 2 incisors (Central and Lateral)
How many primary teeth in total?
20 teeth in total
(10 in each arch)
Dental Sextants
Dentition is divided into 6 segments
- Each arch is divided into 3:
- 5 teeth in each posterior sextants (3 molars, 2 premolars) - right and left side
- 6 teeth in each anterior sextant (2 canines, 4 incisors - Central & Lateral)
Anatomical crown
The part covered by enamel (whole crown of the tooth, whether it has erupted or not)
Always remains the same
Clinical crown
The part of the tooth that can be seen in the mouth (this may include all or only part of the anatomical crown & may even include part of root)
Bifurcation
Division of the root trunk into 2
- found on lower molars
Trifurcation
Division of the root trunk into 3
- provides tooth with maximum anchorage against biting force
- found on upper molars where anchorage is essential
Composition of the tooth structure (Tooth tissues)
- Enamel
- Dentin
- Cementum
- Pulp
Enamel
A hard protective tissue that covers the crown of the tooth
- hardest tooth structure
- smooth (self-cleansing)
- thickest at the tip of the crown, thinner at cervical portion
Dentin
Makes up the main bulk of the tooth
- Found in both the crown and root of the tooth
- softer than enamel, harder than cementum or bone
- can continue to form throughout lifespan of a tooth
Cementum
Covers the root of the tooth
- attaches the tooth to the bone
- softer than enamel or dentin (least calcified tooth)
- light yellow in colour
Pulp
Soft connective tissue containing nerves & blood vessels in the center of tooth (non-mineralized)
- surrounded by dentin
- nourishing and sensory (pain) function
- composed of blood vessels, lymph vessels, connective tissues, nerve tissues and odontoblasts (special dentin formation cells)
Parts of pulp cavity
- Pulp chamber
- Pulp canal
*Pulp horn = extension of the chamber
Common structures of the tooth
- Crown
- CEJ (Cemento-enamel junction) also called Cervical line or cervix
- Root
- Apex (terminal end of root –> Apical foramen = tiny opening in the apex for blood vessels and nerves to enter)
Periodontal Ligament
Suspends the tooth and provides it with nourishment
- located between bone of the alveolar process and cementum
Radicular
Have to do with the tooth root
- the radicular pulp is the pulp contained in the root
Incisors (Location, shape, function)
4 incisors in each arch (2 Central, 2 Lateral)
- Location: Central (side by side at midline); Lateral (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 (helps move food to the posterior part of mouth)
Canines/Cuspids (Location, shape, function)
2 cuspids in each arch
- Location: Next to 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