Thaum yug, calves muaj deciduous (ntev, mis nyuj, menyuam) cov hniav. Cov hniav deciduous ploj lawm raws li tsiaj muaj hnub nyoog thiab lawv hloov los ntawm cov hniav mus tas li.
hnub nyoog twg cov nyuj tau hniav?
Thaum lub sijhawm tus menyuam nyuj yog ib hlis laus, tag nrho 8 lub sijhawm ib ntus feem ntau tshwm sim. Cov pinchers mus tas li tshwm sim thaum muaj hnub nyoog 18 txog 24 lub hlis thiab tau tsim tiav hauv 2 xyoos cov nyuj. Lawv ua raws li qhov tshwm sim ntawm thawj khub niam txiv ntawm incisors ntawm 24 txog 30 lub hlis ntawm hnub nyoog.
Cov menyuam nyuj yug los nrog cov hniav saum toj thiab hauv qab?
Nqaij pib lub neej nrog cov hniav me nyuam. Lawv tau txais lawv thawj cov hniav tas mus li thaum lawv muaj hnub nyoog li 1 ½ - 2 xyoos. Nyuj muaj peb hom hniav: incisors, premolars thiab molars. nyuj tuaj tsis tau vim tsis muaj hniav.
Puas yog nees yug los nrog hniav?
Zoo li tib neeg, nees tau txais ob kab hniav hauv lawv lub neej. Tus me nyuam cov hniav, tseem hu ua deciduous teeth, yog ib ntus. Thawj deciduous incisors yuav tawg ua ntej foal yug. Tus me nyuam cov hniav kawg tuaj thaum tus nees muaj hnub nyoog 8 hli.
Puas yog nees thiab nyuj yug hniav?
Nees yog diphyodontous, erupting ib txheej ntawm cov hniav deciduous thawj zaug (tseem hu ua mis nyuj, ib ntus, los yog cov hniav me nyuam) sai tom qab yug me nyuam, nrog cov no tau hloov los ntawm cov hniav mus tas li los ntawm hnub nyoog kwv yees li tsib xyoos.
