Tooth development eruption and anatomy of primary teeth

Tooth development, eruption and anatomy of primary teeth

Tooth development • Inductio (6 -7 thweek i. u. ) – Initation stage – dental lamina • Proliferatio – Toothbud (8 th week) – Cap stage (9 -10 th week) • Histodifferentiatio – Bell stage(11 -12 th 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: 17 th embrional week Molars: ca. 20 th 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”.

Average eruption times Month Primary teeth Schopf Fehér 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 First incisors

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

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