TOOTHTOOTHdens, dentisdens, dentis

odus, odonotosodus, odonotos

Teeth (Dentes)

• arcus dentalis superior (maxillaris) – ellipse• arcus dentalis inferior (mandibularis) – parabola

• permanent teeth (dentes permanentes) – 32• deciduous teeth (dentes decidui) – 20dens incisivus (= incisor tooth) 8/8

dens caninus (= canine tooth) 4/4

dens premolaris (= premolar tooth) 8/0

dens molaris (= molar tooth) 12/8

Teeth – parts

• crown (corona)

• neck (cervix)

• root (radix)

• pulp (pulpa)

Surfaces and Surfaces and directionsdirections

• occlusalis

• vestibularis (buccalis/labialis)

• lingualis (lower teeth)

palatinalis (upper teeth)

• mesialis

• distalis

Teeth – fixationTeeth – fixation

• gomphosis (socket) = dentoalveolar joint

• located in bony alveolus dentalis of jaw

• periodontium

• parodontium = all structures around tooth

• between tooth and dental alveolus (fixed to the bone of alveolus)

• collagen fibers (serve as alveolar periosteum)• fixation apparatus of tooth = fibers of various

directions• penetrates into cement• rapid change of connective tissue, plasticity –

orthodontics• atrophy in lack of proteins and vitamin C →

scurvy (= skorbut)

PeridontiumPeridontium

PeriodontiumPeriodontium

Scurvy (Scurvy (scorbutscorbut))

Macroscopy of tooth and its fixationMacroscopy of tooth and its fixation

Denture as a wholeDenture as a whole

• mordex = denture• orthodental position – teeth vertically• occlusion (occlusio)• 80 % psalidodontia (scissors-like occlusion) =

norm– progenia = lower jaw longer (lower teeth in front of upper

ones)– stegodontia = roof-like occlusion– prognathia = upper jaw longer (upper teeth in front of

lower ones)– opisthodontia = lower teeth too far behind upper ones– hiatodontia (= mordex apertus)

Dental chart / schemeDental chart / scheme

• crossed with letters – tooth number designed with lower INDEX– lowercase = decicuous– UPPERCASE = PERMANENT

• crossed with numbers– Roman numerals = decicuous– Arabic numerals = PERMANENT

Dental chart / scheme of deciduous teethDental chart / scheme of deciduous teeth

Dental chart / scheme of permanent teethDental chart / scheme of permanent teeth

Dental chart / schemeDental chart / scheme

• binumeral (Féderation Dentaire Internationale)– 1-4 quadrants (from right side above clock-wise)

= PERMANENT– 5-8 (similar) = deciduous

• numeral (American Dental Association)– numerals 1-32 (from right upper third mollar

clock-wise) = PERMANENT– letters A-T (similar from right upper second molar)

= deciduous

Teeth – structureTeeth – structure

• dentine – dentinum (substantia eburnea)

• enamel – enamelum (substantia adamantina)

• cement – cementum (substantia ossea)

• pulp – pulpa– loose connective tissue, vessels, nerves

EnamelEnamel• hardest tissue of body• organic part

– secreted by ameloblasts (enameloblastus)

– glycoproteins (amelogenins, enamelins)

• anorganic part 95%– hydroxyapatite

• arranged vertically in prisms (rods)

• in between interprismatic substance

FluoridationFluoridation

• fluorine is sired under the enamel surface, posteruptivelly from saliva and tooth-paste

• re-covers defects• fluorapatite is more resistant to acids (Ph

4,5) and is produced more quickly than hydroxyapatite (pH 5,5)

• the more fluorapatite is in enamel, the more resistant to dental caries (tooth decay)

• supplement: tooth-paste, salt, at dentist

DentineDentine• calcified connective

tissue• organic part

– collagen I, proteoglycans

– secreted by odontoblasts (dentinoblastus)

• located on internal surface of dentine

• Tomes fibers (fibrae dentinales)

• anorganic part– hydroxyapatite

• non-calcified dentine• predentine• close to enamel and

cement

PulpPulp

• loose connective tissue– fibroblasts– immune cells

soustavy

• vessels

• nerve fibers (senstitive to pain)

CementCement

• thin layer at neck thick layer at root

• fibrilar type of bone

• cellular part – cementocytes

Gum (Gum (GingivaGingiva))

• mucosa attached to periosteum

• stratified nonkeratinizing squamous epithelium

• papilla gingivalis

• no glands• no submucosa

• gingivodental junction

Gum (Gum (GingivaGingiva))

• linea mucogingivalis

• gingiva alveolaris (pars affixa gingivae)– pink, stippled, keratizing

• „free gingival groove“

• gingiva marginalis (pars libera gingivae)– shiny, red, nonkeratinizing

• sulcus gingivalis

• junctio dentogingivalis

• epithelium junctionale

Teeth development Teeth development ((OdontogenesisOdontogenesis))

ectomesenchyme

• oral ectoderm

• mesoderm

• cells of neural crest

• enamel is derived from ectoderm

• other tissues are derived from ectomesenchyme

Teeth Teeth developmentdevelopment

• Week 6: lamina dentalis (dental lamina) appears– thickening of

stomodeum epithelium

• in each lamina 10 proliferation centers– dental buds

Stages of tooth developmentStages of tooth development

• dental bud (status gemmalis)– local thickening of epithelium, 10 in each jaw

• dental cap (status galearis)– ectodermal part → enamel organ (organum

enameleum)– invagination of mesenchyme → dental papilla

Stages of tooth developmentStages of tooth development

• dental cap → dental bell (status campanalis)– outer dental epithelium– enamel reticulum– inner dental epithelium– dental papilla → dental pulp– dental sac → cement, periodontal ligaments

Stages of tooth development – bellStages of tooth development – bell

• odontoblasts (dentinoblasti)– derived from mesenchyme

cells at inner enamel organ– produce (pre)dentine– Tomes fibers (fibrae

dentinales)• cytoplasmatic processes left

within dentine

Stages of tooth development – bellStages of tooth development – bell

• ameloblasts (enameloblasti)– from inner enamel

epithelium– basal surface becomes

secretory– production of enamel

Stages of tooth development – bellStages of tooth development – bell

• epithelial root sheath (vagina epithelialis radicis)

= Hertwig sheath– transition between outer and

inner enamel epithelium– ingrowth into mesenchyme

and induction of root formation

Tooth eruptionTooth eruption• decidual teeth: 6th – 24th month

• enamel organ disrupted during tooth eruption

Permanent teethPermanent teeth• develop similarily to decidual teeth

• secondary dental lamina– located at lingual side of dental lamina– prolonged distally (molars)

• eruption from 6th year

• (finished in 30th – 40th year)

Clinical noteClinical note

• tetracycline antibiotics

are contraindicated in children up to 8 years of age, pregnant and nursing women– high affinity to newly produced enamel– brown-yellow color– enamel hypoplasia