Tooth Morphology: Final Flashcards
What is the order of dimensions for a primary maxillary central?
MD>IC>FL
True or False: MD outlines exhibit more convexity than permanents for primary maxillary centrals
True
Which primary tooth has a possible lingual ridge?
Maxillary Central
True or False: Root is shorter relative to crown height in primary maxillary centrals?
False: longer
What is the root cross section of a primary maxillary central?
Triangular
From an incisal view what is the shape of the primary maxillary central?
Diamond
On which side of a primary maxillary central root is there a concavity?
Mesial
Where is the incisal edge of a primary maxillary central relative the the mid-root axis?
Facial
Which direction is a primary maxillary central deflected?
facially
What are the order of dimensions for a primary maxillary lateral?
IC>MD>FL
What is the outline of a primary maxillary lateral from an incisal view?
Circular
True or False: their is less angle rounding in a primary maxillary later?
False: more angle rounding
What is the outline of a primary maxillary canine?
Diamond
What is unique about the proximal HOC for primary maxillary canines?
M & D HOC at same level with mesial possibly more cervical
Which primary tooth has the longest root?
Maxillary canine
Which cusp ridge is longer in a primary maxillary canine?
Mesial
What is the cross section of the primary maxillary canine root?
Triangular
True or False: The primary maxillary canine has a prominent cingulum and lingual ridges
True
What tooth does the primary maxillary first molar resemble?
Maxillary 1st Pre-Molar
What is the widest crown dimensions of the primary maxillary 1st molar?
FL
How many sides does that occlusal outline of the primary maxillary 1st molar have?
5 sides
Which primary maxillary tooth has a MB bulge?
Maxillary 1st Molar
The oblique ridge of the primary maxillary 1st molar connects which cusps?
ML & DB
The facial CE line of the primary maxillary 1st molar has a curvature towards which side?
Mesial side
What is the largest cusp on the primary maxillary 1st molar?
ML
Where is the facial groove located on the primary maxillary 1st molar?
More distally
True or False: The primary maxillary 1st molar has a prominent mesial marginal ridge?
True
What cusps does the transverse ridge connect on the primary maxillary 1st molar?
ML & MB
How many fossae/pits does the maxillary primary 1st molar have? What is their size order from largest to smallest?
3, mesial>central>distal
Which cusp tip is the longest and sharpest in the primary maxillary 1st molar?
ML
True or False: The primary maxillary 1st molar has a large root trunk?
False; no root trunk (or very short)
True or False: The primary maxillary 2nd molar is smaller than the 1st?
False, it’s larger
Which primary molar has the greatest root divergence?
Maxillary 2nd Molar
Which tooth does the primary maxillary 2nd molar most closely resemble?
Permanent Maxillary 1st Molar
Which primary tooth has a cusp of carabelli?
Maxillary 2nd Molar
Which primary tooth has a more prominent cingulum, but less prominent marginal ridges and lingual fossa?
Mandibular Central
True or False: M & D outlines are evenly convex on a primary mandibular central?
True
On the primary mandibular central where is the incisal edge relative to the mid root axis?
Centered
What are the order of dimensions for a primary mandibular central?
MD>FL>IC
Which direction do the incisal edges slope in a primary mandibular lateral?
Distally
Which direction does that cingulum bulge towards in the primary mandibular lateral?
Distally
Which edge is more rounded in a primary mandibular central?
Distal
What direction does the root of a primary mandibular central lean?
Distally and Facially
Which primary mandibular tooth has the longest root?
Mandibular Canine
Which primary canine is narrower FL and has a sharper cusp tip?
Mandibular Canine
Which primary tooth is unlike any other tooth?
Mandibular 1st Molar
Which dimension is larger in a primary mandibular 1st molar, MD or FL?
MD
On which side of the primary mandibular 1st molar is the OC dimension greater?
Mesial
What is unique about the F and L root surfaces of the primary mandibular 1st molar?
They are almost parallel
Which root is much wider and longer on a primary mandibular 1st molar?
Mesial
Which direction is the facial CE line offset to in the primary mandibular 1st molar?
Mesial
True or False: The primary mandibular 1st molar has a MB bulge?
True
What are the four cusps of the primary mandibular 1st molar from greatest to smallest?
MB>ML>DB>DL
In which teeth is the mesial HOC more cervical than distal?
permanent mandibular 1st pre-molar, permanent mandibular central, primary maxillary canine, primary mandibular 1st molar
Which tooth has a prominent mesial transverse ridge?
Primary Mandibular 1st Molar
True or False: the primary mandibular 1st molar doesn’t have a distal pit?
True
What is unique about the occlusal table of the primary mandibular 1st molar?
It is wider on the distal side than the mesial
Which primary tooth has the narrowest occlusal table?
Mandibular 1st Molar
Which tooth does the primary mandibular 2nd molar resemble?
Permanent mandibular 1st molar
True of False: All three facial cusps are more similar in size in a primary mandibular 2nd molar?
True
True or False: the occlusal table of the primary mandibular 2nd is wider?
False; it’s narrower
True or False: the primary mandibular 2nd molar has very little root trunk?
True
True or false: are the F and L surfaces of the mesial root of a primary mandibular 2nd molar nearly parallel?
True
How much of enamel is inorganic?
96%
What is the fundamental unit of enamel?
enamel rods or prism
What form enamel?
Ameloblast cells
What is the hardness of enamel on the Knoop scale?
300
True or False: Deep enamel is harder than peripheral enamel?
False
What is the hardness of enamel on Moh’s scale?
5-8
True or False: Density increases from DEG to surface?
True
True or False: enamel is prone to splitting
True
What supports/cushions the enamel?
Dentin
What mineral reduces solubility and increases hardness?
fluoride
Which layer of the tooth has pores?
Enamel
What is the chemical composition of enamel??
inorganic 96%, organic 1%, water 3-4%
What is the inorganic component mostly?
hydroxylapatite; Ca10(PO4)6(OH)2
What layer is described as having key hole shape?
Enamel
How do enamel rods radiate from the DEG on primary teeth?
They are perpendicular to the DEG
What are incremental growth lines in enamel called?
Lines of Retzius
What are lines of retzius formed by?
hypomineralized bands
What is the wave like characterization of the lines of retzius called?
Perikymata
What are the alternating light and dark bands of enamel called?
Hunter-Schreger Bands
True or False: The dark bands of the enamel rods are called parazones?
False: diazones
What is the main component of tooth structure?
Dentin
What is dentin formed from?
Odontoblast cells
What makes up the shape of dentin?
Dentinal tubules
What are odontoblast processes?
extensions of odontoblast cells within dentinal tubules
What’s the Knoop hardness of dentin?
65
True or False: Does dentin have an elastic property?
True
True or False: Dentin isn’t very permeable?
False; it’s highly permeable (decreases with age)
What is the chemical composition of dentin?
75% inorganic, 20% Organic, 5% water
How much greater is the presence of fluoride in dentin vs. enamel?
2-3x
Where is fluoride most concentrated?
closer to the pulp
What is the organic portion of dentin mostly made up of?
- Collagen (glycine, alanine, proline, hydroxyproline)
- Some lipids (cholesterol)
Where are the tubules of dentin narrower?
Towards the DEJ
Which is more mineralized, peritubular dentin or intertubular dentin?
Peritubular dentin
What is intertubular dentin mainly made of?
collagenous fibers cross-crossing between tubules
Where are Lines of Owen found?
Dentin
What does the neonatal line show?
demarcation between prenatal and postnatal dentin
Where are neonatal lines found?
In primary teeth and cusps of the permanent first molars
What is tertiary dentin?
Reparative secondary dentin
What is secondary dentin?
Physiologic secondary dentin
What characterizes sclerotic dentin?
tubules obliterated by minerals
What characterizes dead tracts?
tubules with dead odontoblast processes
How does cementum attach to alveolus?
Via sharpey’s fibers and periodontal ligaments
What forms cementum?
cementoblasts
What color is cementum?
light yellow
What is the chemical composition of cementum?
50% inorganic (hydroxylapatite), 50% organic material and water
Where is acellular cementum found?
cervical 2/3 of root
Where is cellular cementum found?
apical 1/3 of root
Why does cellular cementum form?
Result of trauma
What is cellular cementum mainly composed of?
cementocytes
What is acellular cementum mainly composed of?
calcified substance
Where is pulp chamber located?
Within the anatomical crown and cervical 1/3 of the root
Where is the pulp chamber floor located?
Just apical to the CE line
What is the constricted opening at or near the root apex which nerves and blood supply pass through called?
Apical foramen
Where are later accessory canals most often found?
In the apical third of the root
What is an excess canal called?
supplementary canal
What is an anastomosis?
a branch that horizontally connects between canals
What are the functions of the pulp tissue?
Formation of dentin, nutrition, sensation, defense and protection
What is the Zone of Weil
a cell free layer
What is the cell rich zone of the pulp composed of?
fibroblasts, macrophages, lymphocytes
What is in the central pulp region?
blood and lymph vessels, nerve fibers
How many pulp horns does a maxillary central have?
3
How many pulp horns does a maxillary lateral have?
2 or 0
How many pulp horns does a mandibular incisor have?
None
How many canals do mandibular incisors have?
1
Which cavity has the greatest FL dimension of anteriors?
Maxillary canine
How many pulp horns does a maxillary canine have?
None, but has a pointed incisal portion
What is the cervical cross section of a maxillary canine?
oval
How many mandibular canines show two roots and two canals?
6%
What is unique abut the pulp canals of the maxillary first pre-molar?
The diameter of the lingual canal is wider than the buccal canal
Which canal is longest on a maxillary first pre-molar?
Buccal Canal
What’s the cervical cross section of a maxillary first pre-molar?
Bean shaped
How many canals and roots does a maxillary second pre-molar usually have?
one canal and one root
How many pulp horns and canals does a mandibular first pre-molar have?
2 pulp horns and 1 canal
How many pulp horns and pulp canals does a mandibular second pre-molar typically have?
2 or 3 pulp horns and 1 pulp canal
How many pulp horns and canals does a maxillary 1st molar have?
4 pulp horns and 3-4 pulp canals
Which pulp canal is largest on a maxillary 1st molar? What shape is it MD?
Lingual, ovoid
How many pulp horns and canals does a mandibular first molar typically have?
5 pulp horns and 3-4 pulp canals
On a mandibular first molar which cross section of canals is largest and what shape is it?
Distal, ovoid
Which cross section of the canals is smallest in a mandibular 1st molar?
ML
How many pulp horns does a mandibular 2nd molar have?
4
How many canals does a mandibular 2nd molar have?
Usually 3, but sometimes only 2 canals*
What are the order of dimensions for a maxillary central?
IC>MD>FL
What is the widest MD of all anterior teeth?
Maxillary central
What anterior tooth has the most flat facial CE line?
Maxillary central
How many mamelons in a maxillary central?
3
What is the distal HOC of the maxillary central?
Incisal-middle third
What has the longest root of any molar?
Mandibular 1st molar
What molar and cusp are the sharpest?
Maxillary 1st molar, MB cusp