Tooth development, eruption and anatomy of primary teeth

Tooth development

• • • • •

Inductio (6-7thweek i.u.)

–

Initation stage

–

dental lamina Proliferatio

–

Toothbud (8th week)

–

Cap stage (9-10th week) Histodifferentiatio

–

Bell stage(11-12th week)

–

Toothgerm Calcificatio

–

Enamel

–

Dentin Eruptio

–

Root (Hertwig’s epithelial seath)

Eruption

• • • A. Preeruptiv stage B. Eruptiv –prefunctional stage C. Posteruptiv – functional stage The reduced enamel epithelium fused with the oral epithelium lining the oral cavity

Mineralisatio Primary dentition Incisors: 17th embrional week Molars: ca. 20th embrional week Birth:

•

Incisors: crown formation almost completed

•

Canines: crown up to the ½;

•

Molars: crown up to the ¼ .

Eruptio dentis decidui Average eruption times: in month; Usually the lower teeth are erupting first; Crown development: at 2 ½ years completed; Root development: 1 – 1 ½ years later; Tootharch shapes: „U”.

Primary teeth First incisors Lateral incisors Canines First molars Second molars Average eruption times Month Schopf 6-10 10-14 18-24 14-18 24-30 Fehér 8.-12.

9-13 16-22 13-19 25-33

Simptoms of primary teeth eruption

• • • • • •

pain; higher salivary flux, chewing; digestive disorders temperature(37 ° - 38 °C); irritability; Sleep disorders.

Disturbances during dentition

• • • dentitio praecox dentitio tarda dentitio difficilis

eruption cysts

• • •

dens connatalis (dens praelactales) dens neonatale

Primary dentition

•

no diastemas

•

fiziological diastemas

• Relation between the roots of the primary teeth and the crows of the permanent tooth.

Forráss: Ch. Splieth: Kinderzahnheilkunde in der Praxis, Quintessence Verlag, 2002.

Anatomy of primary teeth they are usually smaller then the permanent rare individuall variarion colour: blue-white enamel mineralisation cervically: cingulum thinner layer of enamel and dentin rooths are small, fracturing often Wide pulp wi fiziological root resrption: genetical Mühlreiter – sighns

Mixed dentition Form Size Color Abrasio Mobility (Root resorptio) Okklusal abrasio

•

0 - missing

•

1 - enamel

•

2 - dentin

• https://www.youtube.com/watch?v=Cjv3ENPR9fo&list =UURRXNQCNkMd1_i0BBP-IRJQ • • • • • https://www.youtube.com/watch?v=zLiV-b1jS28#t=11 https://www.youtube.com/watch?v=RxR1iwa69C0 https://www.youtube.com/watch?v=0pzIRg8cW4A#t=7 3 https://www.youtube.com/watch?v=RxR1iwa69C0#t=3 22 https://www.youtube.com/watch?v=5H40I25xR1w