**Tooth Morphology/Anatomy Flashcards
Define morphology
the branch of biology that deals with the form and structure of organisms
Define dentition
the makeup of a set of teeth; their type, number, and position
Define periodontium
the structures that surround and support the teeth
Is the alveolar process considered part of the dentition or the periodontium?
periodontium
What does PDL stand for?
periodontal ligament
Define deciduous dentition
the primary dentition (“baby teeth”)
Define succedaneous dentition
the permanent dentition
Define nonsuccedaneous dentition
Permanent teeth that are not preceded by a primary tooth
This includes molars
What permanent teeth are considered “non-succedaneous”
molars
What is the term for the the type of dentition where both permanent and primary teeth are present?
mixed dentition
How many sextants are in the adult dentition?
six
They are: maxillary right posterior, maxillary left posterior, maxillary anterior, mandibular right posterior, mandibular left posterior, and mandibular anterior
What is the socket within the jawbone in which the root(s) of a tooth are set?
alveolus or lamina dura
What is the highest point of alveolar bone between the adjacent teeth?
the alveloar crest
Does the periodontal ligament allow for slight movement of the tooth?
Yes
The periodontal ligament serves as a cusion between the tooth and the bone when pressure is exerted or when biting, and therefore must allow for some movement.
What is the fibrous connective tissue that makes up the space between the cementum and the alveolus?
periodontal ligament (PDL)
Which of the following describes how healthy attached gingiva appears:
a) thick, stippled
b) smooth, red, shiny
c) enlarged, red, swollen
d) flat, pointed between the teeth
a) thick, stippled
Unhealthy attached gingiva will appear smooth, red, and shiny
Which of the following describes how healthy free gingiva appears:
a) thick, stippled
b) smooth, red, shiny
c) enlarged, red, swollen
d) flat, pointed between the teeth
d) flat, pointed between the teeth
Unhealthy free gingiva will appear enlarged, red, and swollen
Describe the difference between the anatomical crown and the clinical crown?
The anatomical crown is the part of the tooth covered by enamel, and the clinical crown is the part of the tooth that is showing in the oral cavity
What would be a potential cause for seeing the clinical root in the oral cavity?
recession or bone loss
The clinical root is the part of the root surface that is showing in the oral cavity
Describe the difference between the clinical root and the anatomical root?
The clinical root is the part of the root that is showing in the oral cavity, and the anatomical root is the part of the rooth that is covered in cementum
Name the four parts of a tooth
Enamel, dentin, cementum, pulp
What is the name of the hard tissue that covers the anatomical crown?
enamel
What is the hardest tissue in the human body?
enamel
True or False:
Enamel is thinner at the incisal/occlusal area of a tooth, and becomes thicker as it progresses toward the root
False
Enamel is thicker at the incisal/occlusal area of a tooth, and becomes thinner as it progresses toward the root
What is the hard tissue that makes up the majority of a tooth?
dentin
What part of the tooth provides support for the enamel, and provides insulation to the pulp?
dentin
True or False: The bulk of the tooth is the enamel.
False
The bulk of the tooth is dentin.
What is the second hardest tissue in the human body?
dentin
Name the three types of dentin
1) Primary dentin
2) Secondary dentin
3) Tertiary/reparative dentin
What type of dentin forms before the tooth erupts?
a) primary dentin
b) secondary dentin
c) tertiary dentin
d) reparative dentin
a) primary dentin
True or False: Reparative dentin is also known as tertiary dentin.
True
True or False: Certain restorative materials can be designed to encourage the formation of reparative dentin
True
Name the type of dentin that forms as a result of stimuli like trauma or deep caries
tertiary/reparative dentin
What part of the tooth has the highest fluoride content?
Cementum
When looking at a moderate depth cavity preparation, what is an identifying way to tell the difference between enamel and dentin tooth structure?
The dentin will be darker in color than the enamel.
What is the hard tissue that covers the anatomical root of a tooth?
cementum
Name the two types of cementum
1) acellular cementum
2) cellular cementum
Which type of cementum forms at the apex of a tooth as in a response to the loss of enamel?
a) primary cementum
b) acellular cementum
c) vital cementum
d) cellular cementum
d) cellular cementum
What provides the vitality and nutrition to the tooth?
pulp
What part of the pulp is located in the coronal portion of the tooth?
Pulp horns and pulp chamber
Define convex
a surface that curves outward
True or False: An example of a convex anatomical landmark would be a ridge
True
Define this anatomical landmark: a major developmental convexity on or near the occlusal surface of a posterior tooth or the the incisal edge of a canine
cusp
What is the possible fifth cusp on the lingual surface of the mesiolingual cusp on maxillary first molars?
cusp of Carabelli
On what tooth would you find the cusp of Carabelli?
Maxillary first molars
The cusp of Carabelli is the possible fifth cusp on the lingual surface of the mesiolingual cusp on maxillary first molars.
Define mamelon
a raised area on the incisal edges of newly erupted teeth
What is a raised lobe of enamel on the lingual surface found on anterior teeth?
cingulum
Name the three major ridges on posterior teeth
1) triangular ridge
2) transverse ridge
3) oblique ridge
They are further identified according to their location on the tooth surface and direction in which they transverse the occlusal surface.
What is the rounded border of enamel that forms on the mesial and distal boundaries of the occlusal surfaces of posterior teeth and the lingual surfaces of anterior teeth?
marginal ridge
Define this anatomical term: ridge
any narrow, linear, elevation on the surface of a tooth
Define concave
a surface that curves inward
What are the irregular concavities on the surface of a tooth?
fossa
Define this anatomical landmark: pit
small pinpoint depressions located at the junction of developmental grooves or at the termination of those grooves
What forms as a result of faulty or the incomplete formation of developmental grooves?
a pit
What is the name of a groove that is less distinct?
supplemental grooves
On posterior teeth, what is the anatomical concavity that separates the cusps of a tooth?
developmental groove
Which of the following provides an escape for food from the occlusal surface during the mastication process?
a) marginal ridge
b) fossa
c) spillway
d) mamelon
c) spillway
Define this anatomical term: fissure
developmental or supplemental grooves with incomplete closure of enamel
Where is the most common area to find imbrication lines on a tooth?
the cervical third on the facial of anterior teeth
What anatomical feature appears as horizontal, wavelike ripples on anterior teeth?
imbrication lines
Define: height of contour
the greatest bulge on the anatomical crown of a tooth
True or False: Each tooth has only one height of contour
False
What are some reasons that a contact area may be eliminated on a tooth?
tooth movement, loss of adjacent teeth, open contacts in restorations
Define: contact areas
the area where approximating teeth in the same arch touch each other
Where is the only area of the dentition where two mesial surfaces contact each other?
central incisors
Define: embrasure
the spaces adjacent to and surrounding the contact of the teeth in the same arch; named according to the surface of the tooth they approximate
How many embrasures surround the proximal contact area?
4
What embrasure is made up of interdental papilla?
gingival embrasure
What is the term for roots that are divided into two?
bifurcated
What is the term for roots that are divided into three?
trifurcated
What are the only premolars in the permanent dentition to be bifurcated?
maxillary first premolars
Define: furcation
the area of the tooth where the roots divide
Define: furrow
a concavity located coronal to the furcation of multi-rooted teeth
What is the area called where the crown and the root meet?
cementoenamel junction (CEJ)
On multi-rooted teeth, what is the section of the root that extends from the CEJ to the furcation area?
root trunk
What tooth has the shortest root in the permanent dentition?
maxillary central incisors
Which of the anterior teeth typically have a mesioincisal line angle shaped like a right angle?
maxillary central incisors
What is a common area for decay on the lingual surface of permanent maxillary lateral incisors?
lingual pit
What are the two most common teeth to be congenitally missing?
third molars and maxillary lateral incisors
Define: congenitally missing
a condition present at birth where the teeth are not formed
What is the term for a malformation caused by the only two lobes forming a tooth, instead of the normal four?
peg laterals
Define: diastema
a space separating anterior teeth
What permanent teeth are referred to as the “cornerstones” of the mouth
maxillary canines
What teeth have the longest roots in the permanent dentition?
maxillary canines
Why does the cervical third of a tooth appear darker than the incisal/occlusal third?
the enamel is thinner at the cervical aspect, and so the darker shade of the dentin is more visible
Define: canine eminence
a bulge on the surface of the jawbone where it covers the root of a canine tooth
Which tooth is the largest of the permanent maxillary molars?
maxillary first molars
Which of the roots on a permanent maxillary first molar is the largest and longest of the three?
palatal root
On what tooth would you find a cusp of carabelli?
maxillary first molars
Each permanent maxillary first molar has _#__ transverse ridge(s) and __#__ oblique ridge(s)
one transverse ridge and one oblique ridge
Would you find an oblique ridge on the permanent maxillary or mandibular molars?
maxillary
When looking at the trifurcated roots of the permanent maxillary first and second molars, which have the roots spread further apart?
maxillary first molars
What is the smallest tooth in the permanent dentition?
mandibular central incisors
Which direction do the roots of teeth typically point?
distally
Are the anatomical features of the permanent maxillary or mandibular canines less pronounced?
mandibular canines
On the permanent mandibular canine, the anatomical crown is __(shorter or longer)__ and the anatomical root is __(shorter or longer)__ than the maxillary canine?
longer anatomical crown, shorter anatomical root
Which cusp on the permanent mandibular first premolars is the largest?
buccal
Which is the only premolar on the in the permanent dentition that has a mesiolingual groove?
mandibular first premolars
List the three common types of occlusal anatomy on the permanent mandibular second premolars.
H-type
Y-type
U- or C-type
List the names of the buccal cusps on the permanent mandibular first molars.
-mesiobuccal
-distobuccal
-distal
Are the roots bifurcated or trifurcated on permanent mandibular first molars?
bifurcated
What is the major difference in the enamel in permanent and primary dentition?
the enamel is much thinner on primary teeth
Fill in the blank:
The number of cusps on the primary molars is ____ in comparison to the permanent molars.
reversed
What is the benefit of primary teeth not having tight contact areas?
it helps to provide a space for the permanent dentition to erupt
What is a major anatomical quality of the roots on primary maxillary molars?
the trifucated roots are very spread out
How many teeth are in the adult dentition?
32
How many teeth are in the primary dentition?
20
