Dental Anatomy III - Test I Flashcards
What crown remains static throughout a lifetime?
What changes?
In what direction?
Anatomic
Clinical
Apically
What are the 2 types of triangular ridges emanating off of cusps?
Facial
(not lingual)
Lingual
(not facial)
Where do lingual ridges extend to/from on Canines?
Cusp tip to Cingulum
What process occurs in the tooth follicle?
What does the follicle contain?
Center of Calcification
Odontogenic Organ
What develops from “lobes”?
Positive Anatomy
*cusp tips/Incisal edges
What forms Negative Anatomy?
Merging centers of calcification
What develops last in the tooth?
Roots
*ending with Apex
In what direction does Calcification occur?
From Incisal edges/cusps to apex
*Apical 1/3 of root calcifies last
What are the 3 Primary teeth to first complete Root Formation?
At what age?
Maxillary Central Incisor
Mandibular Central/Lateral Incisors
1.5 years
What 2 Primary teeth calcify last?
What age?
Canines
3.25 years
What age is typical for all teeth to have emerged except the Primary 2nd Molars?
At this stage, what is happening to the Permanent teeth?
20 Months
Calcification begins
When does Calcification of Primary dentition begin?
13-16 weeks In Utero
When have all Primary teeth initiated calcification?
18-20 weeks in utero
T/F
Maxillary teeth usually erupt before their Mandibular counterparts
(Primary Teeth)
False
T/F
Males usually erupt Primary dentition before females
False
T/F
Initial Mineralization of Primary Dentition is entirely prenatal
True
What is the last primary tooth to emerge?
When?
2nd Molar
29 Months
At 3.25 years, what is usually complete?
Root formation
*39 months
When does the Primate Space begin to form?
4 years
When is Primary tooth occlusion evident?
3 years
List the permanent teeth that are succedaneous to the primary teeth.
C. and L. incisors
Canines
1st and 2nd Premolars
*premolars replace molars
What 2 teeth emerge around 11 years?
In what order?
Mandibular 2nd Premolar
Maxillary Canine
In a Haplodont, what cusp is Maxillary?
Mandibular?
Protocone
Protoconid
In the Triconodont and Tritubercular, what cusps are Maxillary?
Mandibular?
Paracone, Protocone, Metacone
Paraconid, Protoconid, Metaconid
- these are listed mesial to distal
- *Protoconid always middle
Match the following terms in Humanoid Mandibular Molars: Mesiofacial cusp Distofacial cusp Distal cusp (accessory cusp) Distolingual cusp Mesiolingual cusp
Protoconid Hypoconid Hypoconulid Entoconid Metaconid
What are the Proximal reference angles for the following Maxillary teeth:
Central Incisor
First Premolar
Second Premolar
28 degrees
5 degrees
6 degrees
What are the facial reference angels for the following Maxillary teeth:
Central Incisor
Canine
2 degrees
17 degrees
From the vertical axis, the least deviation is seen in which teeth?
(2 teeth, 2 views)
Maxillary C.I.
(2 degrees, facial view)
1st Premolar
(5 degrees, proximal view)
Why is the ideal plane of occlusion not flat?
Too many contacts in posterior teeth
What does a proper plane of occlusion allow for?
Functional contacts
What does a curved plane of occlusion allow for?
Maximum use tooth contacts during function
What shape does the Proximal Contact Area have in Anterior incisal Teeth?
Incisogingival ovoid
*contact creates embrasures
What Proximal Contact area of the Mandibular Anterior Teeth is not in the Incisal Third?
Distal of Canine
*Middle third
What type of Proximal Contact point is absent in the Mandibular Anterior Teeth?
Junctional
*Incisal or Middle 1/3 (for distal canine)
In what direction does the Proximal Cervical Line bend in the Mandibular Arch?
Where/Measurement in largest bend?
Coronal
C.I. 3.0 mm mesial and 2.0 mm distal
What Periodontal fibers resist impaction of tooth into alveolus?
Oblique
What Periodontal fibers help maintain proximal contacts?
Transseptal
Name 8 types of Periodontal Fibers
Gingival Alveolar crest Circumferential Transseptal Horizontal Oblique Apical Interradicular
Both permanent and primary teeth taper faciolingually. What is the consistent exception?
What are the 2 occasional exception?
Permanent Maxillary 1st Molar
Mandibular 2nd Premolar (Y type)
Primary Maxillary 2nd Molar
What 2 types of line angles are usually more developed?
Facial
Mesial
4 points of comparison for Primary vs. Permanent molar
Smaller size
Prominent Cervical Ridges
Slender Roots
Widely separated Roots
How does the Cervical 1/3 compare in Permanent vs Primary molar?
Flatter contour
Primary Maxillary Lateral Incisor - Incisal view Crown tapers... Incisal ridge curves toward... Slight concavity... Lingual fossa...
Lingually
Facial
Distolingual Profile***
Modestly deep
What is the crown shape of the Facial View of the Primary Maxillary Canine?
Diamond
Where is the cusp positioned in the Primary Maxillary Canine?
Makes what Cuspal Ridge longer?
Slightly distal
Mesial cuspal ridge
How is the Facial Ridge positioned in the Primary Maxillary Canine?
Slightly on Distal half
The root length is ____ the crown length in the Primary Maxillary Canine
The root is curved…
2x
distally
What cusp is not visible in the Mesial view of the Primary Maxillary 2nd Molar?
How many other cusps are there?
Distolingual
4
Which mesial cusp of the Primary Maxillary 2nd Molar is larger?
More pointed?
Mesiolingual
Mesiofacial
What separates the lingual and facial in the Mesial view of the Primary Maxillary 2nd Molar?
Mesial Marginal Ridge groove
How does the crown of the Primary Maxillary 2nd Molar converge from the mesial view?
Cervical line curvature?
Toward Occlusal
negligible
What roots are notable from the Mesial view of the Primary Maxillary 2nd Molar?
How many roots visible from this view?
Lingual deviates outside crown
2
T/F
The roots of the Primary Maxillary 2nd molar are longer than the 1st.
True
What root takes up 2/3 of the CEJ in the Primary Maxillary 2nd molar?
Mesiofacial root
What is the length of the Root Trunk from the mesial view of the Primary Maxillary 2nd Molar?
2-3 mm
T/F
The mesial surface outline of the Primary Mandibular 1st molar is curved
False
Flat
Where are the proximal contact areas of the Primary Mandibular 1st Molar?
Occlusal portion Middle Third
From the facial view of the Primary Mandibular 1st Molar, what cusp is larger?
What separated cusps?
Mesiofacial
Facial developmental groove (indistinct)
Describe the cervical line from the facial view of the Primary Mandibular 1st Molar
Describe cervical ridge
Describe Mesial Root
Dips apically in Mesial half
Convex Mesial half
Longer and straighter
How much bigger is the crown and root in the Mesial portion of the Primary Mandibular 1st Molar?
Crown 20% taller
Root 1/3 longer
What cervical crown is more prominent in the Primary Mandibular 2nd Molar?
Where is the lingual height of contour?
Facial
Middle 1/3
Describe the Mesial Marginal Ridge in a Primary Mandibular 2nd Molar.
Very high
Deep marginal ridge groove
(obscures other topography from mesial view)
T/F
The height of curvature of the cervical line in the Primary Mandibular 2nd Molar is minimal from the mesial view
True
What roots can be seen in the Primary Mandibular 2nd Molar from the mesial view?
only mesial
Describe the Mesial Root of the Primary Mandibular 2nd Molar.
Faciolingually Wide
Long Root Surface Depression
Blunt, serrated Apex
Where is the long root surface depression of the mesial root in the Primary Mandibular 2nd Molar deepest?
Apical 1/3
T/F
Coronal and radicular forms of Dens-in-Dente exist
True
What results from an infolding of dental papilla during development?
What tooth usually affected?
Dens-in-Dente
Lateral Maxillary Incisor
What is usually found in distal 1/3 of molars and facial root furcations?
Enamel Pearls
What are Enamel Projections?
Extensions crown onto root surface between roots
How much shorter is the crown of the Maxillary L.I. compared to the C.I.?
How much less is the crown width?
- 0-1.5 mm
2. 0 mm
Describe the crown outline of the Maxillary Lateral Incisor.
Trapezoidal
Where is the mesial proximal contact area for the Maxillary Lateral Incisor?
Distal contact area?
Junction incisal and middle 1/3’s
Middle 1/3
What direction does the root apex of the Maxillary Lateral Incisor curve?
Distally
How will the incisal edge of the Mandibular Central Incisors be positioned?
Lingually
How much bigger is the enamel edge on the facial side of the Mandibular Central Incisors?
0.5 mm
What are 2 prominent features of the root in the Permanent Mandibular Central Incisor?
Blunt root end
Wide longitudinal root depression extending most of length of root
T/F
Canines are the longest teeth in the mouth, contribute “canine guidance” to functional occlusion, are considered anterior teeth, provides for smile line
True
What shape does a Permanent Maxillary Canine have from the Incisal view?
Diamond
Where is the cusp located in the Permanent Maxillary Canine?
Slightly mesial and facial
*Never distal or lingual
Where is there a slight concavity seen in the incisal view of the Permanent Maxillary Canine?
Distofacially
The facial outline of the crown and root form what shape in the permanent Mandibular Canine?
C - shaped
smooth with no visible concavity
What cusp is taller in the Maxillary 1st Premolar?
By how much?
Facial
1.0 mm
How are the cusp tips of the Maxillary 1st Premolar positioned?
What cuspal ridge is longer?
Mesially
Distal
Describe the shape of the mesial and distal outlines of the Lingual Cusp of the Maxillary 1st Premolar.
Slightly convex
T/F
The crown surface cervical to the level of the contact area will be concave and smooth
False
*convex
From what perspective is the root depression smaller and shallower in the Maxillary 1st Premolar?
T/F
It does not cross the cervical line
Distally
True
Describe the cervical 1/3 of the Root Trunk in the Maxillary First Premolar on the distal surface
Convex
Describe the Cervical Line and Cervical Ridge in the Maxillary 1st Premolar.
Line - little to no curvature
Ridge - 0.5 mm extension outward from the CEJ
What cusp ridge is shorter in the Maxillary 1st Premolar?
Mesial
Where do triangular ridges meet in the Maxillary 1st Premolar?
What usually inhibits a transverse ridge from forming?
Center of Occlusal Table
Deep Central Groove
Describe the position of the central groove in the Maxillary 1st Premolar.
What does it connect?
What extension does it have?
Slightly lingual
Mesial and Distal triangular fossae
Mesial Marginal Ridge Developmental Groove
T/F
Marginal ridges of the Maxillary 1st Premolar are narrow mesiodistally
True
What does the cervical, distal, and mesial outlines of the Maxillary 2nd Premolar produce in appearance?
Oval shape
*this is lingual surface
Describe the root from the Lingual view in Permanent Maxillary 2nd Premolar
Narrower than Facial surface of root
Describe the roots of the Maxillary 2nd Premolar
One root
Apex curves distally
What is found on the root of the Maxillary 2nd Premolar from the distal view?
Longitudinal Depression
*confined to root
T/F
Root depressions are found on mesial and distal aspects of the Maxillary 2nd Premolar and sometimes bifurcates
False
*Does not bifurcate
T/F
The distal contact area of the Maxillary 2nd Premolar is centered faciolingually
True
The mesial and distal cuspal ridges of the Maxillary 2nd Premolar are straight, unaligned, and meet facial cusp at an acute angle.
False
*obtuse angle
The occlusal table is ______ despite the cuspal ridges forming a _______
Rectangular
Continuous Elliptical Arc
Why does the Maxillary 2nd Premolar have a short central groove and wide marginal ridges?
Triangular fossae irregular and close together
What premolar is considered to be nearly bilaterally symmetrical from the facial view?
Mandibular 1st Premolar
Even though the Mandibular 1st Premolar is considered symmetrical, which cuspal ridge is longer?
This means?
Distal
Cusp ever so slightly mesial
How does the triangular ridge of the Mandibular 1st Premolar look from the mesial view?
Steeply inclined
Describe the Lingual Cusp Triangular Ridge and the Central Groove of the Mandibular
Short, horizontall-ish
Groove lingual
What angle is the crest of the Mesial Marginal Ridge in the Mandibular 1st Premolar?
45 degrees
Where is the mesiolingual groove located in the Mandibular 1st Premolar?
Mesiolingual line angle
Where is the Lingual Groove positioned in the Mandibular 2nd Premolar?
(this is 3 cusp variety)
Distally
Which cusp tip is shorter in the Mandibular 2nd Premolar?
By how much?
Mesiolingual (3 cusp variety)
1.5 mm
The distolingual cusp tip is ____ shorter than the facial cisp tip in the Mandibular 2nd Premolar
2.0 mm
What lingual cusp is wider in the 3 cusp variety Mandibular Second Molar?
Distolingual