tooth morphology basics

Tooth Morphology BasicsTooth Morphology Basics

Howard Chi, D.M.D.Howard Chi, D.M.D.

Learning ObjectivesLearning Objectives

• Primary and permanent dentition

• Tooth identification system

• Trait categories

• Tissues of the tooth

• Dental terminology

• Anatomy of tooth structure

• Primary and permanent dentition

• Tooth identification system

• Trait categories

• Tissues of the tooth

• Dental terminology

• Anatomy of tooth structure

Primary and Permanent DentitionPrimary and Permanent Dentition

DentitionDentition

Refers to all of the teeth in the maxillae and the mandible

* maxillary arch - maxillary teeth

* mandibular arch - mandibular teeth

Refers to all of the teeth in the maxillae and the mandible

* maxillary arch - maxillary teeth

* mandibular arch - mandibular teeth

Maxillary arch

Mandibular arch

Humans Have Two Dentitions Throughout Life

Humans Have Two Dentitions Throughout Life

1) Primary Dentition - during childhood

2) Permanent Dentition - during adulthood

1) Primary Dentition - during childhood

2) Permanent Dentition - during adulthood

PrimaryPermanent

Primary DentitionPrimary Dentition

• There are 20 teeth in the primary dentition

• 10 maxillary - 10 mandibular

• This dentition is also termed the deciduous dentition

• There are 20 teeth in the primary dentition

• 10 maxillary - 10 mandibular

• This dentition is also termed the deciduous dentition

Permanent 1st Molars

Primary DentitionPrimary Dentition

The dental formula for one side of the mouth is:

I 2 C 1 M 2 = 10 teeth on either side

2 1 2

The dental formula for one side of the mouth is:

I 2 C 1 M 2 = 10 teeth on either side

2 1 2

11 212

11 212

Deciduous TeethDeciduous Teeth

Those teeth that “fall out” due to a natural process of tooth succession

Those teeth that “fall out” due to a natural process of tooth succession

Permanent Dentition Permanent Dentition

Also called the succedaneous

dentition - that which

succeeds the primary dentition

There are 8 teeth in each quadrant

I 2 C 1 PM 2 M 3 = 16 teeth

2 1 2 3 each side

Also called the succedaneous

dentition - that which

succeeds the primary dentition

There are 8 teeth in each quadrant

I 2 C 1 PM 2 M 3 = 16 teeth

2 1 2 3 each side

Permanent DentitionPermanent Dentition

First signs of this dentition appear at age 6First signs of this dentition appear at age 6

Permanent DentitionPermanent Dentition

A A A P P P P P

Anterior Teeth - incisors and canines

Posterior teeth - premolars and molars

Anterior Teeth - incisors and canines

Posterior teeth - premolars and molars

Tooth Identification SystemsTooth Identification Systems

Tooth Identification SystemsTooth Identification Systems

There are three main systems used in modern dentistry for the numbering of teeth. They are:

* Universal Numbering System

* Palmer Notation System

* International Numbering System

There are three main systems used in modern dentistry for the numbering of teeth. They are:

* Universal Numbering System

* Palmer Notation System

* International Numbering System

Universal Numbering SystemUniversal Numbering System

1. Suggested by Parreidt in 1882

2. Adopted by the A.D.A. in 1975

3. Uses numbers 1 through 32

1. Suggested by Parreidt in 1882

2. Adopted by the A.D.A. in 1975

3. Uses numbers 1 through 32

Universal Numbering System

1 for upper right third molar around to 16

upper left third molar

1 for upper right third molar around to 16

upper left third molar

1 16

Dropping down same side to 17 lower left

third molar and around to 32

Dropping down same side to 17 lower left

third molar and around to 32


1732

For deciduous dentition, letters

A through T are used

For deciduous dentition, letters

A through T are used


A B C D E F G H I J

T S R Q P O N M L K

Universal Numbering

System

Universal Numbering

System

Palmer Notation SystemPalmer Notation System

Utilizes brackets to represent the four quadrantsUtilizes brackets to represent the four quadrants

Upper Right Upper Left

Lower Right Lower Left

• Permanent teeth are labeled 1 to 8 on each side of the midline

• On deciduous teeth same brackets with letters A through E

• Permanent teeth are labeled 1 to 8 on each side of the midline

• On deciduous teeth same brackets with letters A through E

Palmer Notation SystemPalmer Notation System

Palmer SystemPalmer System

International Numbering SystemInternational Numbering System

• Uses two digits for each tooth

• First digit represents dentition, arch and side

• Second number denotes the tooth (1-4 perm. and 5-8 prim.)

• Uses two digits for each tooth

• First digit represents dentition, arch and side

• Second number denotes the tooth (1-4 perm. and 5-8 prim.)


1 = permanent dentition, maxillary, right

2 = permanent dentition, maxillary, left

3 = permanent dentition, mandibular, left

4 = permanent dentition, mandibular, right

5 = primary dentition, maxillary, right

6 = primary dentition, maxillary, left

7 = primary dentition, mandibular, left

8 = primary dentition, mandibular, right

1 = permanent dentition, maxillary, right

2 = permanent dentition, maxillary, left

3 = permanent dentition, mandibular, left

4 = permanent dentition, mandibular, right

5 = primary dentition, maxillary, right

6 = primary dentition, maxillary, left

7 = primary dentition, mandibular, left

8 = primary dentition, mandibular, right

Trait CategoriesTrait Categories


Set Traits: (dentition traits) distinguish teeth in the primary from secondary dentition

Set Traits: (dentition traits) distinguish teeth in the primary from secondary dentition


Arch Traits:

distinguish maxillary from mandibular

Arch Traits:

distinguish maxillary from mandibular

Trait Categories

Trait Categories

Class Traits: Distinguish the four categories of teeth ... incisors, canines, premolars, molars

Class Traits: Distinguish the four categories of teeth ... incisors, canines, premolars, molars


Type Traits: Distinguish teeth within one class Type Traits: Distinguish teeth within one class

Tissues of the ToothTissues of the Tooth

Tissues Of A ToothTissues Of A Tooth

1) Dentin

2) Enamel

3) Cementum

4) Pulp

1) Dentin

2) Enamel

3) Cementum

4) Pulp

EnamelEnamel

• Makes up the protective outer

surface of the anatomic crown

• Mostly inorganic and calcified

hard, white shiny surface of the

anatomic crown

• Makes up the protective outer

surface of the anatomic crown


hard, white shiny surface of the

anatomic crown

DentinDentin

• Found in the crown and root, making up bulk of tooth

• Found beneath the enamel and cementum and surrounding the pulp tissue

• Not normally visible


• Found in the crown and root, making up bulk of tooth

• Found beneath the enamel and cementum and surrounding the pulp tissue

• Not normally visible


CementumCementum

• Makes up the surface of the anatomic root

• Very thin next to cervical line

• Mostly inorganic calcified

• Dull yellow in color

• Makes up the surface of the anatomic root

• Very thin next to cervical line

• Mostly inorganic calcified

• Dull yellow in color

PulpPulp

• Is non calcified found within the

pulp chamber

• Develops from the dental papilla

(from mesoderm)

• Surrounded by dentin except at the

apical foramen

• Is non calcified found within the

pulp chamber

• Develops from the dental papilla

(from mesoderm)

• Surrounded by dentin except at the

apical foramen

PulpPulp

• Normally not visible except on

dental radiographs

• In the coronal portion termed

the pulp chamber

• In the root portion termed the

pulp canal(s)

• Normally not visible except on

dental radiographs

• In the coronal portion termed

the pulp chamber

• In the root portion termed the

pulp canal(s)

Pulp - FunctionsPulp - Functions

• Formative - dentin producing cells (odontoblasts) produce dentin thoughout the life of a tooth

• Sensory - nerve endings permit the sense of pain

• Formative - dentin producing cells (odontoblasts) produce dentin thoughout the life of a tooth

• Sensory - nerve endings permit the sense of pain

Pulp - FunctionsPulp - Functions

• Nutritive - nutrient transport from the blood stream to extensions of the pulp that reach into dentin

• Defensive/Protective - responds to injury and decay by forming reparative dentin

• Nutritive - nutrient transport from the blood stream to extensions of the pulp that reach into dentin

• Defensive/Protective - responds to injury and decay by forming reparative dentin

Junctions Of Tooth StructureJunctions Of Tooth Structure

Cementoenamel Junction - also

called the cervical line,

separates the anatomic crown

from the anatomic root.

Cementoenamel Junction - also

called the cervical line,

separates the anatomic crown

from the anatomic root.


Dentinoenamel Junction - is the inner surface of the enamel cap visible in cross section or in badly worn teeth

Dentinoenamel Junction - is the inner surface of the enamel cap visible in cross section or in badly worn teeth


Cementodentinal Junction - a.k.a. dentinocemental junction is the inner surface of cementum lining the root visible in cross section or badly worn teeth

Cementodentinal Junction - a.k.a. dentinocemental junction is the inner surface of cementum lining the root visible in cross section or badly worn teeth

Anatomic Versus Clinical Crown

Anatomic Versus Clinical Crown

Anatomic Crown - that part of the tooth covered in enamel

Clinical Crown - that part of the tooth that is visible in the oral cavity

Anatomic Crown - that part of the tooth covered in enamel

Clinical Crown - that part of the tooth that is visible in the oral cavity

Dental TerminologyDental Terminology

Terminology Used To Distinguish Tooth Surfaces


Facial Surface - the surface next to the face, the outer surface of a tooth resting next to the cheeks or gums. Used in both anterior and posterior teeth

Facial Surface - the surface next to the face, the outer surface of a tooth resting next to the cheeks or gums. Used in both anterior and posterior teeth



Buccal Surface - the facial surface of posterior teeth. Meaning next to the cheek

Buccal Surface - the facial surface of posterior teeth. Meaning next to the cheek



Labial Surface - the facial surface next to the lips, generally used for anterior teeth

Labial Surface - the facial surface next to the lips, generally used for anterior teeth



Proximal Surface - the surface or side of a tooth that is next to an adjacent tooth, not considered self-cleansing

Proximal Surface - the surface or side of a tooth that is next to an adjacent tooth, not considered self-cleansing

Mesial Surface - is the surface of the tooth nearest to the midline of the dental arch

Mesial Surface - is the surface of the tooth nearest to the midline of the dental arch



Distal Surface - is the surface of the tooth farthest from the midline of the dental arch

Distal Surface - is the surface of the tooth farthest from the midline of the dental arch





Lingual Surface - is the surface of maxillary and mandibular teeth nearest the tongue

Lingual Surface - is the surface of maxillary and mandibular teeth nearest the tongue



Palatal Surface –

is the surface of maxillary teeth

nearest the palate

Palatal Surface –

is the surface of maxillary teeth

nearest the palate



Occlusal Surface - is the chewing surface of the posterior teeth found within cusp and marginal ridges

Occlusal Surface - is the chewing surface of the posterior teeth found within cusp and marginal ridges



Incisal Edge - is the cutting edge, ridge or surface of anterior teeth

Incisal Edge - is the cutting edge, ridge or surface of anterior teeth

Anatomy of Tooth StructureAnatomy of Tooth Structure

Divisions Of The Crown And Root Of A Tooth


Divisions Cervico-occlusallyDivisions Cervico-occlusally

Cervical 3rdMiddle 3rdIncisal 3rd

Cervical 3rdMiddle 3rdOcclusal 3rd

Anterior Posterior

Divisions Of The Crown Of A Tooth

Divisions Of The Crown Of A Tooth

Divisions MesiodistallyDivisions Mesiodistally

Distal 3rd

Middle 3rd

Mesial 3rd

Divsions Of The Crown Of A Tooth

Divsions Of The Crown Of A Tooth

Divisions FaciolinguallyDivisions Faciolingually

Lingual 3rd

Middle 3rd

Facial 3rd



Divisions Cervico-occlusallyDivisions Cervico-occlusally

Apical 3rd

Middle 3rd

Cervical 3rd

Cervical 3rdMiddle 3rdIncisal 3rd

Apical 3rd

Middle 3rd

Cervical 3rd

Cervical 3rdMiddle 3rdOcclusal 3rd

Anterior Posterior

Morphology Of An Anatomic Crown


Cusp - is a point, or peak on the chewing surface of premolar or molar tooth

Cusp - is a point, or peak on the chewing surface of premolar or molar tooth



Cusp Slopes Or Ridges - are the inclined surfaces that form an angle at the cusp tip

Cusp Slopes Or Ridges - are the inclined surfaces that form an angle at the cusp tip

How Many Cusp Ridges Does This Tooth Possess?How Many Cusp Ridges Does This Tooth Possess?



Cingulum - is the enlargement or bulge on the cervical third of the lingual surface of the crown of anterior teeth

Cingulum - is the enlargement or bulge on the cervical third of the lingual surface of the crown of anterior teeth



Labial Ridge - is a ridge running cervico-incisally in approximately the center of the labial surface of the canines

Labial Ridge - is a ridge running cervico-incisally in approximately the center of the labial surface of the canines



Buccal Ridge - is the ridge running cervico-occlusally in approximately the center of the buccal surface of premolars

Buccal Ridge - is the ridge running cervico-occlusally in approximately the center of the buccal surface of premolars



Cervical Ridge - ridge running mesiodistally on the cervical one-third of the buccal surface of the crown, found on all deciduous teeth but only on the permanent molars

Cervical Ridge - ridge running mesiodistally on the cervical one-third of the buccal surface of the crown, found on all deciduous teeth but only on the permanent molars



Marginal Ridge - on incisor and canine located on the mesial and distal border of the lingual surface

Marginal Ridge - on incisor and canine located on the mesial and distal border of the lingual surface



Marginal Ridge - on posterior teeth located on the mesial and distal border of the occlusal surface

Marginal Ridge - on posterior teeth located on the mesial and distal border of the occlusal surface



Triangular Ridge - on the occlusal surface of posterior teeth, is the ridge from any cusp tip to center of the occlusal surface - ML cusp of upper molars have two

Triangular Ridge - on the occlusal surface of posterior teeth, is the ridge from any cusp tip to center of the occlusal surface - ML cusp of upper molars have two



Oblique Ridge - found only on maxillary molars made of the triangular ridges of the mesiolingual and distobuccal cusps

Oblique Ridge - found only on maxillary molars made of the triangular ridges of the mesiolingual and distobuccal cusps

Transverse Ridge - ridge crossing the occlusal surface of posterior teeth in a B-L direction and made of connecting triangular ridges

Transverse Ridge - ridge crossing the occlusal surface of posterior teeth in a B-L direction and made of connecting triangular ridges





Mamelon - is one of three tubercules sometimes present on the incisal edge of an incisor tooth that has not been subject to wear

Mamelon - is one of three tubercules sometimes present on the incisal edge of an incisor tooth that has not been subject to wear



Sulcus - is a broad depression or valley on the occlusal surface of posterior teeth

Sulcus - is a broad depression or valley on the occlusal surface of posterior teeth



Developmental Groove - is a sharply defined, narrow and linear depression, formed during tooth development separating lobes or a major portion of a tooth - a fissure may be found at the depth of a developmental groove

Developmental Groove - is a sharply defined, narrow and linear depression, formed during tooth development separating lobes or a major portion of a tooth - a fissure may be found at the depth of a developmental groove



Supplemental Groove - small irregularly placed grooves not at the junction of lobes or major portions of the teeth

Supplemental Groove - small irregularly placed grooves not at the junction of lobes or major portions of the teeth



Fossa - a depression or hollow found on the lingual surfaces of some anterior teeth and on the occlusal surfaces of posterior teeth

Fossa - a depression or hollow found on the lingual surfaces of some anterior teeth and on the occlusal surfaces of posterior teeth



Pits - often occur at the depths of fossa where two or more grooves join

Pits - often occur at the depths of fossa where two or more grooves join



Furcation - is the place on multirooted teeth where the root trunk or base divides into separate roots

Furcation - is the place on multirooted teeth where the root trunk or base divides into separate roots

RootTrunk

Curve Of SpeeCurve Of Spee

Anteroposterior curve of the occlusal plane - curve of the maxillary arch is convex

Anteroposterior curve of the occlusal plane - curve of the maxillary arch is convex

Curve Of WilsonCurve Of Wilson

Gradual curve of posterior teeth from left to right side viewed from the anterior region - curve of maxillary teeth is convex

Gradual curve of posterior teeth from left to right side viewed from the anterior region - curve of maxillary teeth is convex

tooth morphology basics

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