Teeth and Parodontiumstructure, development

Ivo Klepáček

OROFACIAL SYSTEMMultifunctional complex of structures

CNSMuscles Joints

Teeth Jaws

Periodontium (parodontium)

fonationspeechmasticationdigestion

TEETH PARODONTIUM

TEETH

tooth Dens, dentis lat.

Odus, odontos gr.

DENTES

(dens incisivus, caninus, premolaris, molaris (Y5 formula)

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Zuby –teeth částiparts

• Korunka crown(corona)

• krček neck(cervix)

• kořen root (radix)

• dřeň pulp (pulpa)

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Main termsTEETH PARODONTIUM

Hard tissues:EnamelumDentinumCementum

Soft tissues:Pulpa dentisPeriodontium

ODONTIUMEndodontium Ektodontium Periodontium TEETH PARODONTIUM

Teeth

• Firast and second dentition dentes decidui (lactales), permanentes

tooth masticating cusps rootsI incisal crest 1C 2 oblique crests 1P 2 cusps 1 (2)M - upper 4 ; fissures „H“ 3

- lower 4 (5) ; fissures + 2

„H“

„+“

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upper teeth lower teeth Pulp changes through life

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TEETH PARODONTIUM

FDIFedérale Dentaire InternationaleADAAmerican Dental Association

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Stálé Dočasné

Permanentes Lactei32 20

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Enamelsubstantia adamantinosa

• The most firm body part• Organic part

– Formed by ameloblasts– glykoproteins

(amelogenins, enamelins)

• Anorganic part 95%– hydroxyapatite

• Arranged in prisms• Among them there is the

interprismatic substance

Prisms; interprismaticsubstance, crystals

Ameloblasts

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Ameloblast: structure

Secretion and reabsorbtion during enamelic matrix formation

Tomes fibers

Secretion

Tomes fiber

reabsorbtion

Nexus , desmosomes, tight junctions

Sir John Tomes, (1815-1895), Engl. surgeon

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Enamel structureCrystals, prisms and interprismatic substance (short and long molecules)

Prisms proceed to surface in various angles

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ParazonesDiazones

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Hunter-Schreger strips, striae

Retzius strips, striae

Perikymata ridges, grooves

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Dentinesubstantia dentinum

• calcified connectivetissue

• Organic part– colllagen I,

proteoglycans– Formed by odontoblasts

• Located on the innerdentine surface

• Tomes fibers• Anorganic part

– hydroxyapatite• No-calcified dentine

• predentin• Closely to the enamel and

cementum

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Dentin odontoblasts

dentine tubules

Retzius linesvonEbner

Developmental order:

PrimarySecondaryTerciary

Folowing location:

MantleCircumpulpalInterdentinGlobularPredentin

Odontoblasts, matrix, fibers

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ODONTOBLASTS AND AMELOBLASTS

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Dentine tubulesTomes fibersNaumann sheath /sheet/

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Hypersensitive area Hyposensitive area

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Mantle dentineIntermingling processesgranular

Circumpulpal dentinematrix rich

Interdentine interglobular

Predentinematrix poor

odontoblasts

Dentine structure

External coatMantle dentine

10-30um; contains alfa-fibrills

Inner dentineCircumpulpal dentine

Stripped; exhibits regular secretion and mineralization layers

PredentineAmorphous; area of synthesis; polymorphous, contains proteoglycans, tropocollagen, glycoproteins

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Neonatal line

Incremental lines(associated with dentine maturation) Von EbnerAdresenNeonatalRelation between primary and secondary dentine

Mineralizing in birth

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Cementum = substantia ossea

• Thin layer on theroot

• Similar to thespongy bone

• Cellular part –cementocytes

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CementumCementoblasts, mucoprotein substance, fibers

Cellulare:Collagen fibers + intercellulare substance + cementocytes

Non cellulare:Collagen fibers + intercellular substance

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Relation between cementum, dentine and enamel

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cellular

acelular

Acellular cementum - arrangement

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Cellular cementum - structure

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Hypercementosis

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Pulp

fibroblasts

ramification

• Odontoblasts,• Weil subodontoblastic layer• Layer rich by nuclei

Pulpocytes (mesenchymal cells, fibrocytes)basic substance (collagen fibers, sugars, elastic fibers)free cells (histiocytes, monocytes, plasmatic cells)

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Raschkow´plexus

Nerve fiberswith vesels

Cell contacts

Bipolar pulpocyte

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Epitelové ostrůvky Malassez´epithelial islets

Hertwig´ epithelial sheet

Louis-Charles Malassez (1842-1909), frc. vědecOscar Hertwig (1849- 1922) něm. zoolog a anatom

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Teeth: Vascular and nervous supply

n.V/2 br.alveolares sup. post.br.alveolares sup. ant.

n.V/3 n. alveolaris inf.

plexus dent. (sup., inf.)br. dentales, gingivales

aa. alveolares sup. post.aa. alveolares sup. ant.a. alveolaris inf.

vv. – follow arteries to the pterygoid plexus

lnodi. submandibulares (x M3)

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Functionof the Tooth

fixationsystem

Tooth fixation, elasticity, (hydroelasticcushion) nutrition, asistance duringeruption

0.3-0.5

0.1-0.2

About 0.2 mm

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Periodontium(suspensory system)

Cementum, Lamina corticalisLigg. periodontalia Gingiva (Mucoperiosteum)Cells, fibers, nerves, matrix, plasma, vessels, “hydroelastic pillow“

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PARODONTIUM Periodontium

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Gingiva proper (attached) =

pink, stippled, keratizing

Alveolar mucosa (“loose gingiva“) =

shiny red, nonkeratizing

Gingiva = fibrous tissue + mucous membraneFree: Interdental; embrasured; circumdentalAttached: Adjacent,fixed

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Sulcus gingivae

Paramarginal sulcus

Gingiva = relation to the teeth – “cuff (collar) attachment“

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Gum = Gingiva• Non-keratinized

epithelium -parakeratosis

• Multilayered epithelium

• Gingival groove• Junctional epithelium

– gingivodental junction / closure

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Interdental, circumdental, dentoalveolar, interalveolarligaments

Ligamentous slings and circles help to tight attachment between gingiva and tooth

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Upper dental arch –parabolic curve

Lower dental arch –hyperbolic curve

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Arches

parabolic

hyperbolic

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Exchange of ionts between external environment and pulpTEETH

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True pocket

False pocket

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compressionsucking

bite actions:

“tops on platform““tops on tops“

“combined“

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I1I2

P2P1

M1

M3

M2 C

Normoocclusio Angle I

Edward Hartley Angle (June 1, 1855 - August 11, 1930) American dentist

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frontal

lateral

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Wilson curve

Spee curve

Monson

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Teeth: Variations

and anomalies• Mesiodens• Paramolare• Tuberculum Carabelli• Divergency or convergency of roots • Root fusion• Dens in dente• Hyperplasia of teeth

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Teeth as a whole complexmordex = dentition

• ortodental position (vertical axes of teeth)• articulation = occlusion

– 80% psalidodontia (scissor-like occlusion) = norm– progenia = lower teeth in front of the upper ones– (hiatodontia (= mordex apertus), stegodontia, prognathia,

opisthodontia)

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Anodontia;

hypodontia;

diastema

Abnormality tvaru a polohy; Tooth abnormalities in

shape and position;

Gingivitis

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Bodily shift

Mesial shift

Resorbtion-

Apposition+

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“to palate““to tongue“

“wedge from“

“contact form“

AbrasionVII classes

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Tooth development

• week 6 development of the dental lamina (dental molding)– Thick epithelium

inside oralmucous membrane

• Each molding has about 10 center of the proliferations– Dental buds

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Tooth developmental stages• Dental bud

– Local thick epithelium, 10 in each jaw

• Dental cap– Ectoderm part → enamel organ– Invagination of the mesenchyme → dental papilla

week 8

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• Dental bud (hat) → bell– External dental organ– Dental reticulum– Inner dental organ– Dental papilla → dental pulp– Dentl sac → cementum, periodontal ligaments

Tooth developmental stages

week 8

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• Epithelial dental sheath (cervical sling)– Area of the contact between

inner and outer enamelic epithelium

– Ingrowth to the mesenchyme; root induction

Tooth developmental stages

month 3

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Tooth developmental stages

123

456

Outer layer of the enamel organEnamel pulpInner layer of the enamel organ(ameloblasts)EnamelDentinOdontoblasts

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month 6

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Eruptio -eruption

Teeth appear in jaws as buds in the dental lamina

Tooth penetrates through gingiva to the oral cavity

Deciduous teeth – from month 6. to year 2

i1 i2 m1 c m2

Permanent teeth – from year 6. to year 30

M1 I1 I2 P1 C P2 M2M3

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Examination pictures - examples

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