Dental Anatomy (Lecture 1 and 2)

Transverse Mouth Planes

Maxillary-Upper

Mandibular-Lower

Median Mouth Planes

Right or Left

Name the quadrants of the teeth- where they are located w/numbered teeth.

Quadrant 1- Upper Right Maxillary (#1-8)

Quadrant 2- Upper Left Maxillary (#9-16)

Quadrant 3- Lower Left Mandibular (#17-24)

Quadrant 4- Lower Right Mandibular (#25-32)

Which teeth are apart of the anterior and posterior teeth? And how many?

Anterior- Central Incisors (4 total); Lateral incisors (4 total); Canines (4 total)

Posterior- Premolars (8 total); Molars (12 total: 3 on each side)

What do Incisors do?

CUT

What do Canines do?

PIERCE/HOLD

What do Premolars and Molars do?

CHEW

Primary/Deciduous Dentition: How many teeth? What are the teeth? Numbering system?

Baby teeth

20 teeth> 4 central incisors, 4 lateral incisors, 4 canines, 8 molars

NO PRE-MOLARS

A-T

Secondary/Permanent Dentition: How many teeth? Numbering system?

32 teeth

All adult teeth

Numbered 1-32

What are the steps to naming a tooth?

1. Dentition»»» Primary or Secondary

2. Arch»»»Maxillary or Mandibular

3. Side»»»Left or Right

4. Tooth Name (for example»first premolar)

Universal Naming System

Simplifies the name by using numbers for teeth 1-32

Starts with 1 where it is the MAXILLARY RIGHT 3rd molar

Palmer Notation System

Divided by Quadrants »»»» 4 different brackets

For Permanent teeth»»» 1 through 8 in each bracket

For primary teeth»»» A though E in each bracket

Name the 4 tissues of the tooth

1. Enamel

2. Dentin

3. Cementum

4. Pulp

Name the characteristics of Enamal

• protective external surface layer of anatomic crown

• HARDEST substance in the body

• 95% Calcium Hydroxyapatite»»» highly calcified

Name the characteristics of Dentin

• makes up the bulk of the tooth/underlies the enamel and cementum

• 70% Calcium Hydroxyapitite

• Not normally visible

Name the characteristics of Cementum

• THIN external layer of the anatomic root

• 65% Calcium Hydroxyapatite

• As hard as bone

• Visible on extracted tooth

Name the characteristics of Pulp

• soft, non-mineralized CONNECTIVE tissue

• Not visible

• Blood vessels and nerves

• In the center of crown and root called the pulp cavity

Name the functions of Pulp

• Formative»»» Dentin-producing cells called odontoblasts

• Sensory»»» Can sense pain

• Nutritive»»» transportation of nutrients from bloodstream to the pulp cells

• Protective/Defensive»»» reparative dentin in response to injury

What are the main parts of the periodontium?

• supporting tissues of the teeth

  1. Alveolar bones»»» surrounds the roots

  2. Gingiva (gum tissue)»»» soft tissue covering alveolar bone + VISIBLE

  3. Periodontal ligament»»» connects cementum (root) to the bone

Name all of the Tooth Surfaces.

Facial»»» faced towards cheeks/lips (on ALL teeth)

• Buccal»»» Posterior teeth only

• Labial»»» Anterior teeth only

Lingual/palatal»»»faced towards tongue (think “limba”)

Occlusal»»» the chewing surface of POSTERIOR teeth only

Incisal edge»»» top surface for ANTERIOR teeth only

Mesial»»» Closer to the midline of mouth

Distal»»» Farther from the midline of mouth

What are line angles?

• where 2 tooth surfaces meet

How do you name Line Angles?

• Combine 2 surfaces »»» change the “al” of the first surface to “o”

• Order

  • Mesial » distal, facial (buccal or labial), lingual » occlusal or incisal

What are Point Angles?

Junction line of 3 tooth surfaces

Root-to-Crown ratio

-root length divided by crown length

-normally greater than 1

Smaller ratios signify that the tooth is not the best choice for attaching fake teeth due to the force applied

• LONGER TERM SUCCESS WITH LARGER RATIOS

What are the teeth numbers for maxillary central incisors?

#8 and #9

What are the teeth numbers for the maxillary lateral incisors?

#7 and #10

What are the teeth numbers for the mandibular lateral incisors?

#23 and #26

What are the teeth numbers for the mandibular central incisors?

#24 and #25

What are the 4 functions of incisors?

1. Cut food

2. Enable articulate speech

3. Lip support and aesthetic

4. Guide mandible posteriorly

How many lobes do incisors develop from?

4

What are the 4 developmental lobes?

3 are facial

1 is lingual

What does the lingual developmental lobe form?

The Cingulum

What does the cingulum function as?

Provides support and strength to the tooth

On which teeth are cingulums found?

Incisors and canines

What do the 3 facial developmental lobes eventually turn into?

May Elon’s

What are mamelons?

3 small bulges on the Invisalign edge of newly erupted incisors

What is perikymata?

Numerous thin horizontal ridges on the enamel of newly erupted permanent teeth

Which tooth has the longest incisor crown?

Maxillary central incisor

Is the maxillary central incisor longer incisogingivally or mesiodistally?

Incisogingivally (vertically)

Are mesioincisal angles of incisors sharp or convex?

Sharp (acute)

EXCEPTION: mandibular central incisor (symmetrical)

What does the CEJ of incisors curve towards ?

The apex

For central incisors, which side has the contact area closer to the gum line (cervical)?

Distal surface because of its curve

EXCEPTIONS: mandibular central incisor

In the facial/labial view, the roots of central incisors bend more towards which side?

Distal

EXCEPTION: mandibular centrals» roots are not likely to bend

Which is longer in incisors, roots or crowns?

Roots

As you go from the CEJ to the apex, does it become more wide or narrow?

Narrow (tapers)

From the facial view of maxillary central incisors, which contact area is more Incisal?

Mesial (closer to incisal edge)

In the lingual view of all incisors, what do the mesial and distal ridges converge towards?

Lingual cingulum

What is the area between the mesial and distal marginal ridges from the lingual view called?

Lingual fossa

From the proximal view for all incisors, what shape does it appear as?

Wedge-shaped or triangular

From the proximal view of incisors, the facial outline is more ____ cervically than incisally.

Convex (pronounced outward curve)

From the proximal view of all incisors, how can you describe the shape of the lingual cervical third?

Convex

From the proximal view of all incisors, how can you describe the shape of the lingual middle and incisal thirds?

Concave

From the proximal view of all incisors, the lingual outline is ____ shaped.

S-shaped

From the proximal view of all incisors, the cervical line (CEJ) curves towards the ___ edge.

Incisal edge

From the proximal view of all incisors, the cervical line CURVE is GREATER on the ____than on the ____.

Mesial »» distal

From the Incisal view, is the lingual fossa concave or convex?

Concave

From the incisal view, is the labial outline concave or convex?

Convex

From the incisal view, is the labial or lingual outline more curved?

Lingual is more curved

From the labial view of maxillary incisors, what are the differences in crown shape between the laterals and centrals?

Centrals are WIDER while laterals are NARROWER mesiodistally

Centrals have a LONGER crown

Laterals are peg shaped

For maxillary lateral incisors, where is the distal contact located?

Middle third

For maxillary lateral incisors, where is the mesial contact located?

Incisal third

Which maxillary tooth has a deeper pit?

Lateral incisors

From the lingual view of maxillary central incisors, where is the cingulum pointed?

Distally

From the lingual view of maxillary lateral incisors, where is the cingulum pointed?

It is more centered

From the lingual view, are maxillary or mandibular incisors more smooth?

Mandibular

Important!!

From the lingual view of maxillary incisors, the distal marginal ridges appear (shorter/longer) than mesial because why?

SHORTER

Because the incisal edge has a greater slope towards the distal AND because the cingulum is placed distally (mostly for centrals).

EXCEPTION: mandibular centrals

For maxillary incisors (lingual), which marginal ridge is longer?

Mesial ridges are LONGER

For maxillary incisor roots, where do they curve?

Distally

What are the differences between maxillary central and lateral incisors from the PROXIMAL view?

Central» more CONCAVE lingually and root outline is MORE convex lingually

Lateral» root is even and more symmetrical

Important!!!

From the lingual view, maxillary incisors have the CEJ curve MORE (mesially/distally).

Mesial

On which tooth is the largest proximal CEJ curve for all teeth?

Maxillary central incisor

From the proximal view, what is the difference between the cervical third and apical third of the root?

Maxillary central has a flatter lingual outline in cervical, then tapers towards the apex

Laterals have an overall uniform taper

From the INCISAL view for maxillary incisors, is the width or length larger?

Width, longer mesiodistally

(Not true for mandibular)

From the incisal view, what shape does the maxillary central incisor have?

Triangular outline

From the incisal view, what’s shape does the maxillary lateral incisor have?

Round or oval outline

T/F: From the incisal view, the maxillary lateral is more convex than centrals.

True

Name the Main traits of the maxillary central incisor. (From labial view)

• WIDEST crown of all incisors

• WIDER mesiodistally than faciolingually

• LONGEST tooth crown

• SMALLEST root to crown ratio

• Mesioincisal angle is close to a right angle

What are the lingual characteristics of maxillary central incisor?

• lingual anatomy is more prominent than mandibular centrals

• Cingulum is DISTAL

What is 1 key characteristic of the maxillary central incisor ? (Proximal view)

Incisal ridge is CENTERED to the root.

On which surface does tooth wear occur on for maxillary central incisors?

LINGUAL surface (Angle class 1)

Name 2 key traits of the maxillary central incisor from the incisor view?

• wider mesiodistally than faciolingually

• Outline is TRIANGULAR

On the lingual aspect of a maxillary incisor, how does the distal marginal ridge compare in length to the mesial marginal ridge?

A. Distal marginal ridge is longer

B. Distal marginal ridge is shorter

C. Distal marginal ridge is equal to the mesial marginal ridge

B. Distal marginal ridge is shorter

Name the main characteristics of the maxillary lateral incisor from the FACIAL view.

• crown is smaller than central

• Has a LONGER, more slender look

• Mamelons are LESS prominent than on maxillary central incisors

Name the main characteristics from the LINGUAL view of the maxillary lateral incisor.

• lingual anatomy is more prominent than other incisors

• Smaller lingual fossa AREA than maxiallry central

• CENTERED CINGULUM

• Has a deep pit

Name the main characteristics from the INCISAL view of the maxillary lateral incisor.

-outline is round/oval

-incisal ridge is centered

Name the main characteristics of the mandibular central incisor form the facial view.

-smallest incisor

-Alike and nearly same size

- Mesial contact areas closer to the incisal ridge and SAME level

-MOST SYMMETRICAL TOOTH In the mouth

Name the main characteristics of the mandibular central incisor form the lingual view.

• SMOOTH lingual surface with less prominent anatomy

• Root is LONGER than crowns than maxillary incisors

• Root-crown ratio is LARGER

• CENTERED cingulum

Name the main characteristics of the mandibular central incisor form the incisal view.

• Centered cingulum

• WIDER faciolingually than mesiodistally

• STRAIGHT incisal ridge

On which surface does tooth wear occur on the mandibular central incisor?

FACIAL surface (angle class 1)

What is 1 key trait ab mandibular central incisors from the PROXIMAL view?

Incisal ridge is pointed LINGUALLY

Name the main characteristics of the mandibular lateral incisor form the facial view.

• Slightly WIDER than mandibular central

• Longer root

Name the main characteristics of the mandibular lateral incisor form the Lateral view.

• Smoother lingual surface with LESS prominent anatomy than maxillary incisors

• Cingulum is located DISTAL

• MESIAL marginal ridge appears to be LONGER than distal

Why does the MESIAL marginal ridge appears to be LONGER than distal on mandibular lateral incisors?

Because the cingulum is located DISTALLY

Name the main characteristics of the mandibular lateral incisor from the INCISAL view.

• cingulum is located distal to the midline

• DISTOLINGUAL TWIST of the incisal ridge

What are the two main differences between the mandibular lateral and central incisors from the LABIAL view?

1. Lateral is LARGER than central

2. Lateral is a distoincisal angle that is MORE ROUNDED than mesioincisal

   1. MESIO and DISTO-incisal angles are EQUAL and sharper on centrals

What is a characteristic of the root shape of mandibular incisors?

Distal BEND of root tip is more common

What do mandibular incisors have on their root than are more PROMINENT than in maxillary?

Root depressions (visible through proximal views where distal is deeper)

Where does the CEJ curve on mandibular incisors from the PROXIMAL view?

CEJ curves more on the MESIAL than distal.

MOST CEJ curvature is on the mesial of central

(Same as maxillary)

True or False. Like the maxillary lateral incsiors, the mesial marginal ridge on the mandibular lateral incisors is LONGER than the distal marginal ridge.

True

From the proximal view, are the roots in mandibular incisors wider faciolingually or mesiodistally?

Faciolingually