Permanent Maxillary Central Incisors Overview

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Questions and Answers

What is the primary shape characteristic of the permanent maxillary central incisors?

Squared/rectangular (correct)

Oval

Triangular

Round

At what age does the crown of the permanent maxillary central incisor typically complete its development?

6-7 years

4-5 years (correct)

5-6 years

3-4 years

Which aspect of the permanent maxillary central incisor features a predominantly concave surface?

Distal aspect

Labial aspect

Palatal aspect (correct)

Mesial aspect

What is notable about the mesial margin compared to the distal margin of the permanent maxillary central incisor?

It is longer and straighter Signup and view all the answers

Which feature is found on the labial aspect of the permanent maxillary central incisors?

Four line angles visible Signup and view all the answers

What term describes the appearance of the ridges on the palatal aspect of the permanent maxillary central incisors?

Distinct Signup and view all the answers

What is the most significant feature of the cingulum on the palatal aspect?

Convex and located near the cervical margin Signup and view all the answers

Which description accurately characterizes the apex of the root of the permanent maxillary central incisor?

Blunt and cone-shaped Signup and view all the answers

Which of the following statements correctly describes the curvature of the cervical line on the mesial aspect?

Greater curvature than the distal aspect Signup and view all the answers

What effect does the addition of maleic acid have on glass ionomer cement (GIC)?

It enhances the adhesive properties by increasing carboxylic acid groups. Signup and view all the answers

What bond type is primarily involved in the bonding of GIC to collagen?

Hydrogen bonds Signup and view all the answers

Which statement accurately describes the moisture sensitivity of GIC?

Aluminum ions leaching out may result in poor strength. Signup and view all the answers

Which of the following factors can improve the setting characteristics of GIC?

Application of a conditioner before placing GIC Signup and view all the answers

What is one of the major disadvantages of using GIC in clinical applications?

Poor wear resistance Signup and view all the answers

Which condition is necessary for establishing a strong bond between GIC and tooth structure?

Using a 10-20% polyacrylic acid solution for surface cleaning Signup and view all the answers

Which characteristic distinguishes the cusp of the mandibular canine compared to the maxillary canine?

It is less pointed and occupies only 1/5 of the crown height. Signup and view all the answers

At what age does the crown of the maxillary canine typically complete development?

6-7 years Signup and view all the answers

Which anatomical feature is more developed in the palatal aspect of the canine compared to incisors?

Cingulum Signup and view all the answers

What is the shape of the mandibular canine root's cross-section?

Oval Signup and view all the answers

Which aspect of the mandibular canine is characterized by less pronounced features compared to the maxillary canine?

Lingual aspect Signup and view all the answers

What is the main developmental feature of the mandibular canine root at the apex?

It can present with bifurcation. Signup and view all the answers

How does the contact area of the mandibular canine's mesial aspect differ from its distal aspect?

The distal aspect has a more pronounced curvature. Signup and view all the answers

What developmental characteristic is shared by both maxillary and mandibular canines?

Both exhibit calcification seen first at 4-5 months. Signup and view all the answers

What distinct line characteristic is observed on the labial aspect of canines?

Shorter mesio-incisal line angle compared to the distal angle. Signup and view all the answers

What is a unique morphological feature of canines compared to incisors?

Canines have a more pronounced cingulum. Signup and view all the answers

Which of the following features is true about the maxillary lateral incisors in relation to the maxillary central incisors?

They are smaller than maxillary central incisors. Signup and view all the answers

At what age does the first signs of calcification for maxillary lateral incisors typically begin?

10-12 months Signup and view all the answers

What is the most common developmental anomaly associated with maxillary lateral incisors?

Variations in form Signup and view all the answers

Which aspect of the maxillary lateral incisors demonstrates a deeper palatal concavity?

Cingulum is usually prominent. Signup and view all the answers

What is a common characteristic of the mesioincisal angle in maxillary lateral incisors compared to the distal angle?

The mesioincisal angle is sharper. Signup and view all the answers

Which of the following statements about hypodontia related to maxillary lateral incisors is accurate?

It is the most common tooth to be congenitally missing. Signup and view all the answers

Which statement correctly describes the incisal line of maxillary lateral incisors?

It slopes more on the mesial aspect than centrals. Signup and view all the answers

How does the labial aspect of maxillary lateral incisors compare to maxillary central incisors?

It is more convex and narrower mesiodistally. Signup and view all the answers

At what age do maxillary lateral incisors typically complete their crown development?

4-5 years Signup and view all the answers

What characteristic distinguishes the mesial aspect of mandibular incisors from the distal aspect?

Greater curvature of the CEJ in the mesial aspect Signup and view all the answers

Which feature is accurate regarding the appearance of a mandibular central incisor?

It has a symmetrical shape and is triangular. Signup and view all the answers

What is the significance of the incisal edge in relation to the long axis of the mandibular lateral incisor?

It is at a right angle to the long axis. Signup and view all the answers

At what age does the crown of the mandibular lateral incisor typically complete development?

4-5 years Signup and view all the answers

Which statement describes the root structure of a mandibular lateral incisor?

The apex generally has a labial inclination. Signup and view all the answers

How does the appearance of the maxillary canine compare to that of the mandibular lateral incisor?

The maxillary canine has the longest root in the dentition. Signup and view all the answers

Which aspect of the maxillary canine development is false?

Eruption occurs at 6-7 years of age. Signup and view all the answers

What is a distinguishing feature of the root structure of the mandibular central incisor?

It is often distally inclined at the apical third. Signup and view all the answers

What is true regarding the incisal ridge of the mandibular central incisor?

It is positioned at an acute angle to the long axis. Signup and view all the answers

Which statement accurately describes the labial aspect of the mandibular lateral incisor?

The dimension is slightly greater than that of the central incisor. Signup and view all the answers

Study Notes

Appearance of Permanent Maxillary Central Incisors

Located on either side of the midline and ideally appear as mirror images
FDI numbers: 11 and 21
Widest permanent incisor mesiodistally
Square/rectangular appearance
Symmetrical crown

Development of Permanent Maxillary Central Incisors

First sign of calcification: 3-4 months of life
Crown complete by 4-5 years
Eruption: 7-8 years

Labial Aspect of Permanent Maxillary Central Incisors

Convex from mesial to distal and cervical to incisal
4 line margins/line angles visible (mesial, distal, incisal, cervical)
2 angles visible (mesioincisal, distoincisal)
Mesial Margin: longer and straighter than distal
Mesioincisal angle is relatively sharp compared to the distoincisal
Incisal margin is straight after the mamelons wear off
Root: cone shaped with a blunt apex

Palatal (Lingual) Aspect of Permanent Maxillary Central Incisors

Predominantly concave surface
Mesial and distal present as distinct ridges
Often has a shovel shaped appearance
Cingulum located near the cervical margin - a convex feature
Lingual fossa - deepest part - towards the incisal
A ridge of enamel may point toward the incisal margin dividing this surface in two

Mesial and Distal Aspects of Permanent Maxillary Central Incisors

Triangular/wedge shaped - base at the cervix and apex at the incisal tip
Cervical curvature of the CEJ is greater on the mesial aspect
Distal aspect is similar but CEJ is less exaggerated
Contact Area: incisal 1/3

Appearance of Permanent Maxillary Lateral Incisors

FDI numbers: 12 and 22
Complement the central incisors in appearance and function
Second in the incisor sequence
Smaller than the maxillary central incisors (except root length)
Same features as central incisors but often condensed/exaggerated

Development of Permanent Maxillary Lateral Incisors

First signs of calcification: 10-12 months
Crown completion: 4-5 years
Eruption: 8-9 years
Mamelons are present in young teeth but are less pronounced than in centrals

Variations in Appearance of Permanent Maxillary Lateral Incisors

Display the most variation in form (apart from 3rd molars)
If the variation is too great, it is considered a developmental anomaly
Common: maxillary lateral incisors of non-descript conical pointed form - peg laterals

Hypodontia of Permanent Maxillary Lateral Incisors

Most common tooth to be congenitally missing, either singly or bilaterally in 1-2% of the population

Labial Aspect of Permanent Maxillary Laterals

Mesioincisal angle is sharper than distal
Mesioincisal and distoincisal angles are more rounded than centrals
Labial surface is more convex than maxillary centrals
Narrower mesiodistally and shorter cervicoincisally than maxillary centrals
Incisal line slopes more on the mesial aspect than centrals

Palatal Aspect of Permanent Maxillary Laterals

Mesial and distal margins are more pronounced than in centrals
Cingulum is usually prominent, making the palatal concavity appear deeper
A large, pointed tubercle may also be present on the cingulum
Deep pit may be present in the cingulum - foramen caecum - this may extend towards the root
Carefully examine this area using triplex air syringe - caries predilection spot

Mesial and Distal Aspects of Permanent Maxillary Laterals

Wedge shaped
Mesial aspect displays greater curvature of the CEJ than the distal
Distal surface is quite rounded, similar to the mesial aspect on the canine
Root appears longer - shaped as a tapered cone
Apical end can be pointed or blunt
Contact Area: incisal 1/3

Root Structure of Permanent Maxillary Laterals

Same length as the central's root - may be longer
Apical 1/3 is often distally inclined and terminates sharply
Narrow/flattened mesiodistally

Appearance of Permanent Mandibular Central Incisors

Smallest tooth in permanent dentition
FDI numbers: 31 and 41
Smooth labial surface with no clear developmental lines
Mamelons are present when newly erupted - wear off rapidly if in normal occlusion

Development of Permanent Mandibular Central Incisors

First sign of calcification: 3-4 months
Crown complete by 4-5 years old
Eruption: 6-7 years
Most likely the first succedaneous tooth in the mouth

Labial Aspect of Permanent Mandibular Central Incisors

Regular and convex
Crown is 2x long as wide
Symmetrical in shape
Roughly triangular - narrow at the cervix
Rounded CEJ
Mesioincisal angle is relatively sharp compared to the distoincisal
Incisal ridge at a right angle to the long axis

Lingual Aspect of Permanent Mandibular Central Incisors

Lingual surface is smooth and slightly concave from incisal to cervical
Less concave from mesial to distal
Lingual cingulum, mesial and distal marginal ridges are less defined than in maxillary incisors
Rarely are lingual pits/fissures present
Root tip may have a slight distal curve

Mesial and Distal Aspects of Permanent Mandibular Central Incisors

Triangular in outline
Base is towards the root
Cervical line (CEJ) outline may be the same on both sides
If a difference in CEJ is present, then the mesial aspect presents with greater curvature
Incisal edge has a labial inclination as a result of occlusal wear
Contact area: incisal 1/3

Permanent Mandibular Lateral Incisor

Closely resembles the mandibular central
FDI numbers: 32 and 42
Slightly larger and is more asymmetric in shape than the mandibular central
Distodevelopmental lobe is wider than that of the mandibular central
Slightly wider mesiodistally
Longer incisocervically

Development of Permanent Mandibular Lateral Incisors

First sign of calcification: 3-4 months
Crown complete by 4-5 years
Eruption: 7-8 years of age

Labial Aspect of Permanent Mandibular Lateral Incisors

Usually greater mesiodistal dimension by 1 mm
Mesial side slightly higher than the distal
Incisal edge slopes down towards the distal
Mamelons are present in newly erupted teeth

Lingual Aspect of Permanent Mandibular Lateral Incisors

Ridges are slightly more developed than centrals
Lingual fossa appears shallow - a lingual pit may also be present
Root can be considerably longer than in mandibular central
Proximal grooves often give the appearance of a double root
Apex may have a labial/distal inclination

Root Structure of Permanent Mandibular Lateral Incisors

Root: delicate
Flattened mesiodistal
Longitudinal grooves on mesial and distal
Distal groove is often deeper than mesial
Apex may have a distal deflection

Appearance of Permanent Maxillary Canine

3rd tooth from the midline
Last of the anterior teeth
Single root and cusp
Longest root in the dentition
Seizing/tearing food
Incisal edge/ridge is replaced by a cusp tip and line margins (cusp ridges)

Appearance of Permanent Maxillary Canine

FDI numbers: 13 and 23
Morphologically and functionally share characteristics with both incisors and premolars

Development of Permanent Maxillary Canine

First evidence of calcification: 4-5 months
Crown complete by 6-7 years
Eruption: 11-12 years

Canine Features

Cusp tip replaces the incisal edge/ridge present in other anteriors
Cusp tip lies in line with the long axis of the tooth
Narrower mesiodistally than maxillary central incisors

Labial Aspect of Permanent Maxillary Canines

Convex mesiodistally and cervicoincisally
Mesioincisal line angle is shorter than the distal
Made up of 4 lobes - 3 facial lobes and 1 lingual
Midfacial lobe extension is most developed and forms a cusp tip
Cusp tip occupies approximately 1/3 of crown height
2 shallow developmental grooves on the labial aspect are sometimes present

Palatal Aspect of Permanent Maxillary Canines

Palatal lobe makes the cingulum, which is more developed than incisors - canines are wider labiopalatally
If a well-developed lingual ridge is present, then mesial and distal lingual fossae are visible
Palatal aspect may also be smooth
Palatal aspect is smaller than the labial

Mesial and Distal Aspects of Permanent Maxillary Canines

Wedge shaped
Labial surface is more convex than the incisors from this view
Contact surface towards the incisal 1/3 mesially and in the mid 1/3 distally
Root appears conical from this view

Root of Permanent Maxillary Canines

Long and robust root
Root shape: triangular on a cross section - this helps to resist anterior, posterior, and lateral displacement forces
Root is wider labially than palatally
Root apex is generally blunt
May have a palatal or distal inclination

Appearance of Permanent Mandibular Canines

FDI numbers: 43 and 33
Closely resembles the maxillary canine
Crown is narrower than the maxillary canine but can be the same height
The cusp occupies only 1/5 of the crown height
Cusp is less pointed than the maxillary canine

Development of Permanent Mandibular Canines

First sign of calcification: 4-5 months
Crown complete by 6-7 years
Generally erupt around 9-10 years

Root of Permanent Mandibular Canines

The root is as long as in the maxillary canine (may even be longer)
Root is oval in cross section and shows distinct developmental depressions on mesial and distal surfaces
Can be quite pointed at the apex
Lower canine may present with a bifurcation at the apical 1/3 of the root

Labial Aspect of Permanent Mandibular Canines

Mesioincisal line angle is shorter than the distal
Pronounced labial ridge
Crown may be slightly longer and more symmetrical than the maxillary
Cusp tip not as developed as in maxillary canine's crown

Lingual Aspect of Permanent Mandibular Canines

Lingual features are less pronounced than in the maxillary canine
Less developed cingulum and thinner marginal ridges
No lingual pits present
Lingual fossae are less developed

Mesial Aspect of Permanent Mandibular Canines

Wedge shaped and a pointed cusp
Cusp tip is on the long axis of the tooth
Cervical line curves towards the incisal
Contact area is towards the mesioincisal angle

Distal Aspect of Permanent Mandibular Canines

The whole surface is more curved than the mesial
Cervical line shows less curvature toward the cusp tip
Contact area towards the incisal 1/3

Spectrum of Tooth Colored Filling Materials (Dr Touraj, L1: GIC)

Composite resin: most versatile and widely used esthetic material
Compomer: combines features of composite and GIC
GIC: offers fluoride release and chemical bonding to tooth structure
Resin-modified GIC: improved strength and wear resistance compared to conventional GIC
ORMOCER: an alternative to traditional composites, offering specific advantages and disadvantages

GIC Setting (Dr Touraj, L1: GIC)

Powder: contains fluoroaluminosilicate glass, pigments, and fillers
Liquid: composed of polyacrylic acid, HEMA, photoinitiators, and other additives

Tartaric Acid in GIC (Dr Touraj, L1: GIC)

Improves working time and reduces setting time
Contributes to better homogeneity in the cement mix, leading to improved mechanical properties
Interacts with polyacrylic acid and glass particles, promoting release of calcium (Ca) and aluminum (Al) ions

Maleic Acid and Itaconic Acid in GIC (Dr Touraj, L1: GIC)

Enhance the adhesive properties of the GIC by increasing the number of carboxylic acid groups available for bonding to the tooth surface
Help create a denser cross-linked network within the cement matrix, leading to improved compressive, tensile, and flexural strength
Influence setting characteristics of the cement, aiding in the release of fluoride and calcium

GIC Bonding to Tooth Structure (Dr Touraj, L1: GIC)

GIC can bond to dentine and enamel
Bonding to calcium apatite via ionic bonds
Bonding to collagen via hydrogen bonds
Surface cleaning and conditioning, especially with 10-20% polyacrylic acid, is necessary for long-term bonding, particularly to dentine
Tensile strength of bonding is low compared to resin bonding agents
Conditioner is recommended for placing GIC in long-term cavities
10% Polyacrylic acid solution is applied for 20 seconds to modify smear layer

Moisture Sensitivity of GIC (Dr Touraj, L1: GIC)

Aluminum ions may leach out due to contact with saliva, leading to poor strength
Contamination with saliva or blood results in poor aesthetics, strength, and bonding
Drying retards the setting reaction
Careful isolation and application of a protective cover (varnish, GIC coat, or light-activated bonding agents) is recommended for 24 hours
Higher powder/liquid ratio reduces setting time and increases strength

Problems with GIC (Dr Touraj, L1: GIC)

Erratic dispensing
High solubility
Poor aesthetics
Low strength and toughness
Moisture sensitive
Poor wear resistance

Clinical Indications of GIC (Dr Touraj, L1: GIC)

Class I and II restorations in low-stress areas
Lining under composite restorations
Sealants
Core build ups in non-load bearing situations
Pulp capping materials
Tooth bonding applications
Fluoride release

Advantages and Disadvantages of GIC (Dr Touraj, L1: GIC)

Advantages: fluoride release, biocompatibility, chemical adhesion to tooth structure, thermal expansion similar to tooth structure
Disadvantages: moisture sensitivity, poor wear resistance, high solubility, poor aesthetics compared to composites, lower strength

Resin-Modified GIC (Dr Touraj, L1: GIC)

Powder: radiopaque fluoroaluminosilicate glass, pigments
Liquid: polyacrylic acid, HEMA, photoinitiators
Advantages: improved strength and wear resistance compared to conventional GIC
Disadvantages: lower fluoride release compared to conventional GIC, slightly more expensive

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Description

This quiz covers the appearance, development, and characteristics of permanent maxillary central incisors. Learn about their physical features, calcification timeline, and the detailed aspects of their shape and structure. Test your understanding of these key dental elements.