Dental Anatomy Lecture 2

Incisors

The front 4 teeth

Central-lateral

Mesial surface of right central incisor contacts the mesial surface of the left central incisor unless there is a space.

Why do we need to learn about each tooth morphology, shape, and function?

To restore and manage the oral health of the patient

What tooth numbers are the central maxillary incisors?

8 and 9

What tooth numbers are the lateral maxillary incisors?

7 and 10

What tooth numbers are the central mandibular incisors?

24 and 25

What tooth numbers are the lateral mandibular incisors?

23 and 26

Functions of incisors

Cut food

Enable/articulate speech

Lip support and esthetic

Guide the mandible posteriorly

How many lobes do the class traits develop from?

4

How many facial developmental lobes?

3

How many lingual developmental lobes?

1 (cingulum)

Three Mamelons

From 3 labial developmental lobes before they wear down, like the little grooves on the incisal edge of newly erupted incisors

What are the two incisal elevations?

Mamelons and Perikymata

What is Perikymata?

Numerous horizontal ridges on the enamel of newly erupted permanent teeth

What shape is the incisal edge from the facial view of the maxillary central incisors?

Straight or slightly curved

What shape is the incisal crown from the facial view of the maxillary central incisors?

Rectangular

Longer incisogingivally

Which direction does the incisal crown taper from the facial view of the maxillary central incisors?

From the widest area/proximal contacts to the cervical third

Which set of incisors have the longest crowns?

Maxillary central incisor

Are crowns more convex distally or medially in the facial view of the maxillary central incisors?

Distal, the contact point is more cervical because of this

How are the mesioincisal angles shaped from the facial view of the maxillary central incisors?

Acute, sharp

Which direction do the incisal edges slope in the facial view of the maxillary central incisors?

Cervically towards the distal

What does incisogingivally mean?

From the incisal edge to the gingival edge

What teeth are the exception to most of the morphology in this lecture? Why?

Mandibular central incisors

They are extremely symmetrical

Which direction does the cervical line curve in the facial view of the maxillary central incisors?

Towards the apex, in the middle of the facial surface

How do the contact points differ mesially and distally in the facial view of the maxillary central incisors?

The contact points are more cervical on the distal surface than the mesial

How do the roots taper in the proximal view of the central incisors?

From the cervical line to the apex

Which direction and at what place in the root can it bend in the proximal view of the maxillary central incisors?

More often towards the distal, bending at the apical third

Which is longer, roots or crowns, in central incisors?

Roots

Where are the mesial and distal marginal ridges located at on the maxillary central incisors? Where do they converge?

Located on the lingual side of the tooth, converging towards the lingual cingulum

Where is the lingual fossa located on the maxillary central incisors?

Between the marginal ridges

From the proximal view, what shape is the crown of the maxillary central incisors?

Wedge-shaped, triangular

Where on the crown is the facial outline most convex when looking proximally at the maxillary central incisors?

In the cervical third

The crest of curvature is here both facially and lingually

Is the lingual cervical third concave or convex when looking proximally at the crown of the maxillary central incisors? What about the middle and incisal thirds?

Lingual: Convex

Middle: Concave

Incisal: Concave

What shape is the lingual outline of the crown on the maxillary central incisors?

S-shaped

Which direction does the cervical line curve in the proximal view of the maxillary central incisors?

Towards the incisal edge

On which proximal side is the cervical line curve greater?

Mesial side

Is the lingual fossa concave or convex in the incisal view of the maxillary central incisors?

Concave

What is the incisal ridge?

The edge of the tooth at the biting surface

Which has a longer and wider crown: Maxillary central or lateral incisor?

Central, lateral is more narrow mesiodistally

Which incisor is often missing or peg-shaped?

Maxillary lateral

Which has a deeper pit and larger cingulum: Central or lateral maxillary incisor?

Laterals