Deciduous teeth

Deciduous teeth, otherwise known as milk teeth, baby teeth, temporary teeth, primary teeth are the first set of teeth in the growth development of humans and many other mammals. They develop during the embryonic stage of development and erupt during infancy. They are usually lost and replaced by permanent teeth.

Deciduous teeth start to form during the embryo phase of pregnancy. The development of deciduous teeth starts at the sixth week of development. This process starts at the midline and then spreads back into the posterior region. The eruption of these teeth begins at the age of six months and continues until twenty-five to thirty-three months of age. The first teeth seen in the mouth are the mandibular centrals and the last are the maxillary second molars.

The deciduous dentition is made up of central incisors, lateral incisors, canines, first molars, and secondary molars. All of these are replaced with a permanent counterpart except for the first and second molars; they are replaced by premolars. The deciduous teeth will remain until the age of six. At that time, the permanent teeth start to appear in the mouth. The eruption of permanent teeth causes root resorption, where the permanent teeth push down on the roots of the deciduous teeth causing the roots to be dissolved and become absorbed by the forming permanent teeth. The process of shedding deciduous teeth and the replacement by permanent teeth is called exfoliation. This may last from age six to age twelve. By age twelve there usually are only permanent teeth remaining.

Teething age of deciduous teeth: Central incisors: 6-12 months Lateral incisors: 9-16 months Canine teeth: 16-23 months First molars: 13-19 months Second molars: 22-33 months Deciduous teeth are considered essential in the development of the oral cavity by dental researchers and dentists.

The permanent teeth develop from the same tooth bud as the deciduous teeth. Also the muscles of the jaw and the formation of the jaw bones depend on the primary teeth in order to maintain the proper space for permanent teeth. The roots of deciduous teeth provide an opening for the permanent teeth to erupt. These teeth are also needed for proper development of a child's speaking and chewing of food.

Ex.19. Translate the following words and word-combinations:

Тимчасові зуби, молочні зуби, постійні зуби, перший набір зубів, центральний різець, латеральний різець, ікло, замінюватися постійними зубами, починатися з середньої лінії, прорізування зубів, залишатися до шести років, призводити до розсмоктування коренів, формування постійних зубів, випадіння молочних зубів, м’язи щелепи, залежати від, бути необхідним для правильного розвитку.

Ex.20. Answer the questions:

1. What are deciduous teeth? 2. What synonyms for “deciduous teeth” can you name? 3. When do the baby teeth develop? 4. When do deciduous teeth start to form? 5. When does the development of deciduous teeth start? 6. When does the eruption of temporary teeth begin?

7. What are the first teeth seen in the mouth? 8. What is the deciduous dentition made up?

9. What does the eruption of permanent teeth cause? 10. What is exfoliation?