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)

• A. Preeruptiv stage• B. Eruptiv –prefunctional stage• C. Posteruptiv – functional stage

Eruption

The reduced enamel epithelium fused with the oral epithelium lining the oral cavity

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 .

Mineralisatio Primary dentition

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”.

Average eruption timesMonth

Primary teeth Schopf Fehér

First incisors 6-10 8.-12.

Lateral incisors 10-14 9-13

Canines 18-24 16-22

First molars 14-18 13-19

Second molars 24-30 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

• dens connatalis• (dens praelactales)• dens neonatale

eruption cysts

Primary dentition

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

• no diastemas

• fiziological diastemas

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=73

• https://www.youtube.com/watch?v=RxR1iwa69C0#t=322

• https://www.youtube.com/watch?v=5H40I25xR1w