Dental Anatomy: Maxillary Incisors Flashcards
What number is the right central maxillary incisor?
left central?
right: 8
left: 9
For the central maxillary incisors:
when does Initial Calcification occur?
3-4 mo
For the central maxillary incisors:
when is Enamel Development completed?
in 4-5 years
When do the central maxillary incisors erupt?
7-8 years
For the central maxillary incisors:
when is Root Development completed?
after 10 years
For the maxilary central incisor, what is the avg. crown length?
from CEJ to Incisal Edge length =
10.5mm
For the maxilary lateral incisor, what is the avg. crown length?
CEJ to Incisal Edge =
9mm
On average, maxillary central incisors are wider mesiodistally / buccolingually?
mediodistally
On average, mediodistally ___1___ maxillary incisors are wider than ___2___ maxillary incisors.
- Central (8.5mm)
- Lateral (6.5mm)
On average, the crown length of the central maxillary incisors is
shorter/longer/equal to
the crown length of the lateral maxillary incisors.
longer
On average, the root length of the central maxillary incisors is
shorter/longer/equal to
the root length of the lateral maxillary incisors.
equal to
- but the lateral maxillary incisor’s root appears longer because it has a shorter crown length.
- both are ~13mm
On average, the central maxillary incisors are overall
shorter/longer/equal in length to
the lateral maxillary incisors.
longer
On average, mediodistally the crowns of the central maxillary incisors are
narrower/wider/equal to
the lateral maxillary incisors.
wider
- Cervical Line
- Cingulum
- Mesial Marginal ridge
- Labioincisal Edge
- Distal Marginal Ridge
- Lingual Fossa
- Linguoincisal Edge
- Linguoincisal Edge
- Distal Marginal Ridge
- Cingulum
- Labioincisal Edge
- Lingual Fossa
- Medial Marginal Ridge
Describe: Incisal Ridge
- term onlt used when the incisor first errupts (prior to having been worn down)
- the complete incisal portaiton including mesioincisal and distoincisal angles and labial and lingual surfaces
Describe: Incisal Edge
- term used after adult tooth worn down from use (mammelons worn down/no longer visible)
- does not exist until occlusal wear has created a flattened surface linguoincisally
- formed by the merging of 2 flat surfaces
- formed by the junction of the linguoincisal surface (also called incisal surface) and labial surface
- note: linguoincisal surface = incisal surface
- because labioincisal surface becomes worn down/no longer identfiable from linguoincisal surface
- note: linguoincisal surface = incisal surface
Function of Incisors
- cutting and shearing instruments
- esthetically pleasing- enhance facial configuration, symmetrical
- phonetically play major role in proper enunciation of certain speech sounds (l, f, v, etc)
Describe the distinctive features of the Labial Aspect of the Maxillary Central Incisors
- Mammelons
- present at eruption
- mesial, middle, distal
- mesial and distal = size
- middle is smallest
- Facial Development Grooves may be present
- Mesial Contact Point
- located in the incisal third
- near the mesioincisal angle
- Distal Contact Point
- located at the incisal and middle third junction
- more cervical than the mesial contact point
Mammelons
- present at eruption (are worn away with use)
- mesial, middle, distal
- mesial = distal size
- middle smallest
Facial Development Grooves
- M = Mesial Contact Point
- located in the incisal third
- near the mesioincisal angle
- D = Distal Contact Point
- located at the incisal and middle third junction
- more cervical than the mesical contact point
Describe the distinctive features of
the Lingual Aspect of the Maxillary Central Incisors
- Cingulum
- can be off-center towards distal
- Accessory Lingual Ridge (may be present)
- near cingulum
- Lingual Fossa
- pronounced/distinctive
- CEJ
- Smaller radius Lingually (vs Labially)
Describe the Proximal Aspect of Maxillary Central Incisor
- Crown Outline Form
- wedge-shaped or triangular
- Facial Height of Contour
- located at the cervical third of the crown
- Lingual Height of Contour
- located on teh cingulum
- cervical 1/3 of crown
- CEJ
- significant mesial and distal curvature
- Bisecting Line
- incisal rideg and root apex centered within it
- Morphologic Variation
- shovel-shaped incisors
- deep lingual fossa and prominent marginal ridges
- common in Asian, Eskimo-Aleuts and N & S American Indians
- shovel-shaped incisors
What is centered within the bisecting line of the Maxillary Central Incisors?
incisal ridge and root apex
Describe the Incisal Aspect of the Maxillary Central Incisor
- crown outline
- triangular
- incisal ridge
- centered over the root
- labial surface
- broad and flat
- lingual surface
- tapers towards the cingulum
From the Incisal Aspect, which feature of the Maxillary Central Incisors can’t you see?
the CEJ
- incisal edge is centered directly over the root
- root is cone shaped
- incisal edge is wider mesio-distally than the root
- The crown is wider labio-lingually than the root
Describe the Maxillary Central Incisor from the radicular perspective
- root is cone shaped
- cross-section
- root is rounded triangle
- root = straight
- may lean/curve distally
- Mesial and Distal development root depression may exist
Describe the pulp cavities of the maxillary central incisors.
- 1 Canal
- narrow towards incisal edge
- largest portion located cervically
- Tapers Apically
- CONE SHAPE
For the Maxillary Lateral Incisor, Describe the labial aspect.
- resembles central incisor
- but is smaller in ALL DIMENSIONS
- except root length
- mesial outline
- resembles adjacent central incisor
- distal outline (esp. dsital incisal angle
- more rounded than mesial
- distal incisal angle
- resembles the mesial aspect of adjacent canine
- incisal edge
- rounded
- mesial contact point
- junction of middle and incisal thirds
- Distal contact point
- center of middle third
For the Maxillary Lateral Incisor, Describe the lingual aspect.
- marginal ridges
- usually prominent
- terminate into a prominent cingulum
- cingulum is centered
- *pit where marginal ridges converge gingivally
- developmental groove
- extends across the distal of the cingulum onto the root continuing for part or all of its length (usually towards distal)
For the Maxillary Lateral Incisor, Describe the proximal aspect.
- resembles central
- except root appears longer
- line through long axis of tooth bisects the crown and incisal edge (incisal edge at center of crown)
For the Maxillary Lateral Incisor, Describe the incisal aspect.
- resembles central
- Crown Outline Form
- wedge-shaped or triangular
- Facial Height of Contour
- located at the cervical third of the crown
- Lingual Height of Contour
- located on the cingulum
- cervical 1/3 of crown
- Crown Outline Form
CEJ
* significant mesial and distal curvature
* Bisecting Line
* incisal ridge and root apex centered within it * but also can resemble canine (esp as go distally)
Describe the Radicular aspect of the Maxiallary Lateral incisors
- root generally resembles central incisor
- root is cone shaped
- cross-section
- root is rounded triangle
- root = straight
- common: lean/curve distally
- Mesial and Distal development root depression may exist
Name a few common morphological variation in Maxiallary Lateral Incisors.
- peg-shaped
- missing
- large pointed tubercle as part of cingulum
- deep pelatoradicular groove that extends down on root
- twisted root
- distorted crown
(see 3rd to last slide for more pics or google)
Describe the pulp cavities of the Maxillary Lateral Incisor.
- 1 canal
- narrow towards incisal
- largest portion located cervically
- tapers apically
*sounds a lot like which tooth?
