the jaws incisor canine premolar molar

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Human Dentition

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Page 1: The Jaws Incisor Canine Premolar Molar

Human Dentition

Page 2: The Jaws Incisor Canine Premolar Molar

DENTAL ANATOMY NOMENCLATURE

The Jaws

Page 3: The Jaws Incisor Canine Premolar Molar

DENTAL ARCHES

Page 4: The Jaws Incisor Canine Premolar Molar

• A. THE MAXILLA

is two bones forming

the upper jaw; they are rigidly

attached to the skull.

B. THE MANDIBLE

is a horse-shoe shaped bone which articulates with the skull by way of the temporo-mandibular joint the TMJ.

Page 5: The Jaws Incisor Canine Premolar Molar

Quadrants:right & left quadrants

Maxillary right and left.

Mandibular right and left.

4 Quadrants

Page 6: The Jaws Incisor Canine Premolar Molar

Functions of Teeth

*Efficient mastication of food.

*Maintenance of a normal facial appearance.

*Formulation of clear speech.

Incisor Canine Premolar Molar

Page 7: The Jaws Incisor Canine Premolar Molar

1- Mastication:

Incisors Canine Premolar Molar

Chisel like Cutting or

incising

Wedge like

Cutting and

tearing

At least two projections

(cusps.) Tearing and

grinding

Multiple projection

s (cusps )

Grinding

Page 8: The Jaws Incisor Canine Premolar Molar

4- Growth of jaws:The teeth play a role in the growth of the jaws in some periods of life.

2- Appearance: - Well arranged clean teeth with proper alignment give nice appearance to the face. – Teeth give support to the facial expressions.

3- Speech: for clear pronunciation and production of sound.

Page 9: The Jaws Incisor Canine Premolar Molar

Types of

Teeth

Page 10: The Jaws Incisor Canine Premolar Molar

Anterior Teeth

for cutting &

tearing foodPosterior Teeth

Page 11: The Jaws Incisor Canine Premolar Molar

•Incisors function as cutting or shearing

instruments for food.

•Canines possess the longest roots of all teeth

and are located at the corners of the dental

arch.

•Premolars act like the canines in the tearing

of food and are similar to molars in the

grinding of food.

•Molars are located nearest the

temporomandibular joint (TMJ), which serves

as the fulcrum during function.

Page 12: The Jaws Incisor Canine Premolar Molar

Anterior Teeth- Upper CanineCentral

Incisorslateral

Anterior Teeth- Lower

lateral CanineCentral Incisors

Page 13: The Jaws Incisor Canine Premolar Molar

PREMOLARS: (IN PERMANENT ONLY)

Page 14: The Jaws Incisor Canine Premolar Molar

First premolar & Second premolar

Upper

Lower

Page 15: The Jaws Incisor Canine Premolar Molar

Molars

First second Upper

Lower

Wisdom tooth =Third permanent molar

Page 16: The Jaws Incisor Canine Premolar Molar

Single-rooted

Multi-rooted

Page 17: The Jaws Incisor Canine Premolar Molar

Types of Dentitions:Primary & Permanent Dentition

Page 18: The Jaws Incisor Canine Premolar Molar

• Deciuous Set of Teeth.: – 2 incisors, – 1 canine,– 2 molars in each quadrant

• Permanent Set of Teeth.:– 2 incisors,– 1 canine, – 2 premolars,– 3 molars in each quadrant

Types& forms:

Page 19: The Jaws Incisor Canine Premolar Molar

Types of

Dentitions:

I-Primary

Dentition

Page 20: The Jaws Incisor Canine Premolar Molar

a. Twenty ( 20) primary teeth. b. 10 in each arch c. 5 in each quadrant

In function: 2 years 12 years

6 years 12 years

Eruption of first permanent

molar

Shedding of last primary

molar

Deciduous ,baby, milk teeth:

Page 21: The Jaws Incisor Canine Premolar Molar

ERUPTIONFrom 6 months to 2 years:

pure deciduous dentition

* At three years all roots are complete

From 6y to 12 y:

mixed dentition

From 12 y onwards:

pure permanent dentition

Page 22: The Jaws Incisor Canine Premolar Molar

Mixed Dentition

Period

Page 23: The Jaws Incisor Canine Premolar Molar

6 years ERUPTION OF FIRST PERMANENT MOLAR

Page 24: The Jaws Incisor Canine Premolar Molar

In function: 12 years

through out life

Page 25: The Jaws Incisor Canine Premolar Molar

SURFACES OF TEETH ARE IDENTIFIED BY THE RELATIONSHIP TO SURROUNDING OROFACIAL STRUCTURES

•Apical•Labial•Lingual•Distal•Mesial•Incisal

Teeth: Identification Tooth Surfaces

Labial

Apical

Lingual

Distal

Apical

Mesial

Incisal Incisal

Each tooth has Five surfaces:

Page 26: The Jaws Incisor Canine Premolar Molar

•Apical: Pertaining to the

apex or root of the tooth

•Labial: Pertaining to the

lip; describes the front

surface of anterior teeth

•Lingual: Pertaining to

the tongue; describes the

back (interior) surface of

all teeth

•Distal: The surface of the

tooth that is away from

the median line

•Mesial: The surface of

the tooth that is toward

the median line

palatal

Page 27: The Jaws Incisor Canine Premolar Molar

Functioning Surfaces:

OCCLUSAL: chewing surfaces of

posterior teeth

INCISAL: the anteriors’ biting

surface

chewing/biting surfaces of teeth:

Page 28: The Jaws Incisor Canine Premolar Molar

Enamel

Alveolar Bone

PulpChamber

Oral Anatomy and Physiology

•Enamel•Dentin•Pulp Chamber•Odontoblast Layer•Periodontal Ligament•Gingiva•Alveolar Bone•Cementum•Pulp Canals•Apical Foramen

The Dental Tissues:Dentin

Odontoblast Layer Gingiva

Periodontal Ligament

Cementum

Pulp Canals

Apical Foramen

Page 29: The Jaws Incisor Canine Premolar Molar

•Anatomic Crown

•Anatomic Root

•Pulp Chamber

The 3 parts of a tooth: Anatomic Crown

Anatomic Root

PulpChamber

Oral Anatomy and Physiology

Page 30: The Jaws Incisor Canine Premolar Molar

Anatomic Crown

Anatomic Root

PulpChamber

Oral Anatomy and Physiology

•THE ANATOMIC CROWN is the portion of the tooth covered by enamel.

•THE ANATOMIC ROOT

is the lower two thirds of a tooth.

•THE PULP CHAMBER

houses the dental pulp, an organ of myelinated and unmyelinated nerves, arteries, veins, lymph channels, connective tissue cells, and various other cells.

Page 31: The Jaws Incisor Canine Premolar Molar

Oral Anatomy and Physiology

•ENAMEL•DENTIN•CEMENTUM•DENTAL PULP

The 4 main dental tissues:

Enamel

Dentin

Cementum

Dental Pulp

Page 32: The Jaws Incisor Canine Premolar Molar

•STRUCTURE•Highly calcified and hardest tissue in the body•Crystalline in nature•Enamel rods

•INSENSITIVE—no nerves•Acid-soluble—will demineralize at a pH of 5.5 and lower •Cannot be renewed•Darkens with age as enamel is lost•Fluoride and saliva can help with remineralization

DENTAL TISSUES—ENAMEL2

• ENAMEL CAN BE LOST BY:3,4

• Physical mechanism• Abrasion (mechanical wear)• Attrition (tooth-to-tooth contact)

• ABFRACTION (LESIONS)• Chemical dissolution • Erosion by extrinsic acids (from diet)• Erosion by intrinsic acids (from the oral

cavity/digestive tract)

• MULTIFACTORIAL ETIOLOGY• Combination of physical and chemical factors

Page 33: The Jaws Incisor Canine Premolar Molar

•Softer than enamel

•Susceptible to tooth wear

(physical or chemical)

•Does not have a nerve supply

but can be sensitive

•Is produced throughout life

•Will demineralize at a pH of 6.5

and lower

DENTAL TISSUES—DENTIN2

•Three

classifications

•Primary

•Secondary

•Tertiary

Page 34: The Jaws Incisor Canine Premolar Molar

THREE CLASSIFICATIONS:

•PRIMARY DENTIN forms the initial shape of the tooth.

•SECONDARY DENTIN is deposited after the formation of the primary dentin on all internal aspects of the pulp cavity.

•TERTIARY DENTIN, or “reparative dentin” is formed by replacement odontoblasts in response to moderate-level irritants such as attrition, abrasion, erosion, trauma, moderate-rate dental caries, and some operative procedures.

DENTAL TISSUES—DENTIN2

Page 35: The Jaws Incisor Canine Premolar Molar

TYPES OF DENTIN

Dentin

Primary physiologic dentin

Secondary physiologic dentin

Tertiary dentin orreparative dentin orreactionary dentin or

irregular secondary dentin

Mantle dentin

Circumpulpal dentin

Peritubular dentin

Intertubular dentin

Page 36: The Jaws Incisor Canine Premolar Molar

Dentin

Pulp

Tubule

Fluid Nerve Fibers

Odontoblast Cell

•DENTINAL TUBULES connect the dentin and the pulp (innermost part of the tooth, circumscribed by the dentin and lined with a layer of odontoblast cells)

•The tubules run parallel to each other in an S-SHAPE COURSE

•Tubules contain FLUID AND NERVE FIBERS

•External stimuli cause movement of the dentinal fluid, a hydrodynamic movement, which can result in short, sharp pain episodes

DENTAL TISSUES—DENTIN (TUBULES)2

Page 37: The Jaws Incisor Canine Premolar Molar

•Presence of tubules renders dentin permeable to fluoride

•Number of tubules per unit area varies depending on the location because of the decreasing area of the dentin surfaces in the pulpal direction

Page 38: The Jaws Incisor Canine Premolar Molar

ASSOCIATION BETWEEN EROSION AND DENTIN HYPERSENSITIVITY3

• Open/patent tubules

– Greater in number

– Larger in diameter• Removal of smear layer• Erosion/tooth wear

Enamel

ExposedDentin

RecedingGingiva

Tubules

Odontoblast

Page 39: The Jaws Incisor Canine Premolar Molar

ORAL ANATOMY AND PHYSIOLOGY

•Thin layer of mineralized tissue covering the dentin

•Softer than enamel and dentin

•Anchors the tooth to the alveolar bone along with the periodontal ligament

•Not sensitive

DENTAL TISSUE—CEMENTUM2

Page 40: The Jaws Incisor Canine Premolar Molar

• The Pulp is a soft MESENCHYMAL CONNECTIVE TISSUE

that occupies pulp cavity in the central part of the teeth.

• It is a special organ because of the unique environment

• DENTAL TISSUE—DENTAL PULP2

Page 41: The Jaws Incisor Canine Premolar Molar

*THE CORONAL PULP: it is present in the

pulp chamber. *THE RADICULAR

PULP: it is that part of the

pulp extending from the cervical region of the crown to the root apex.

*APICAL FORAMEN: The pulp organs are

continuous with the periapical tissue through the apical foramen.

MORPHLOGY

Page 42: The Jaws Incisor Canine Premolar Molar

They are commonly seen to extend from the radicular pulp latrally through the root dentin to the periodontal ligament.

They are numerous in the apical third of the root.

Accessory canals

ACCESSORY CANALS:

Page 43: The Jaws Incisor Canine Premolar Molar

CORONAL PULP

• It is the pulp occupying the pulp

chamber of the crown of the

tooth

• In young teeth it resembles the

shape of the OUTER DENTIN

• IT HAS SIX SURFACES : occlusal,

mesial, distal, buccal, lingual

and floor.

• PULP HORNS are projections

into the cusp

• THIS PULP CONSTRICTS at the

cervical region where it

continues as the radicular pulp

Page 44: The Jaws Incisor Canine Premolar Molar

RADICULAR PULP

• It is the pulp occupying the pulp canals of the ROOT OF THE TOOTH

• In the anterior tooth it is SINGLE and in the posterior teeth it is MULTIPLE

• The radicular portions of the pulp is CONTINUOUS with the periapical tissues through apical foramen

• As AGE advances the width of the radicular pulp is reduced, and so is the apical foramen. www.rxdentistry.blogspot.com

Page 45: The Jaws Incisor Canine Premolar Molar

APICAL FORAMEN

• Pulp cavity terminates at root

apex as small opening called

APICAL FORAMEN

• RADICULAR PULP continuous

with connective tissue of the

PERIODONTIUM through this

foramen.

• WIDE OPEN during

development of root

• Sometimes apical opening is

found on the LATERAL SIDE OF

THE APEX

• There may be 2-3 foramina

split by cementum or dentin-

APICAL DELTA

Page 46: The Jaws Incisor Canine Premolar Molar

ACCESSORY CANAL

• Leading LATERALLY from the radicular pulp into the periodontal tissue.

• Present in the APICAL THIRD of the root sheath cells

• Formed due to premature loss of HERS or when developing root encounters a blood vessel.

• Overall occurrence is 33%

• May also be present at the FURCATION REGION

Page 47: The Jaws Incisor Canine Premolar Molar

FUNCTIONS OF THE DENTAL PULP

NUTRITION: blood supply for pulp and dentin.

SENSORY: changes in temp., vibration and

chemical that affect the dentin and pulp.

FORMATIVE: the pulp involve in the support,

maintenance and continued formation of

dentin. (dentinogenesis)

PROTECTIVE: Development and formation of

secondary and tertiary dentin which increase

the coverage of the pulp.

Page 48: The Jaws Incisor Canine Premolar Molar

• First line of defense to injuries and infection of dentine• Tertiary dentine• Immuno-competent• Clearance of toxic substances

DEFENSIVE: triggering of

inflammatory and immune

response.

Page 49: The Jaws Incisor Canine Premolar Molar

DENTIN_PULP COMPLEX

Dentin and pulp are

embryologically,

histologically, and

functionally the same

tissue and therefore are

considered as a complex

Both dentin and pulp

have a common origin

from the dental papilla.