OPTION 2

 

• The development of the first permanent molar is initiated at the fourth month in utero.

• The second molar is initiated at about the first year after birth, the third molar at the fourth or fifth years.

• The distal proliferation of the dental lamina is responsible for the location of the germs of the permanent molars in the ramus of the mandible and the tuberosity of the maxilla.

• The successors of the deciduous teeth develop from a lingual extension of the free end of the dental lamina opposite to the enamel organ of each deciduous tooth .

• The lingual extension of the dental lamina is named the successional lamina and develops from the fifth month in utero (permanent central incisor)to the tenth month of age (second premolar).

 

 

 

 

Key concept

 

• The permanent first molars usually appear in the oral cavity when the child is 6 years old. The mandibular molars precede the maxillary molars.

• The first permanent molar (maxillary or mandibular) erupts posterior to the second deciduous molar, taking up a position in contact with it.

• Therefore the first molar (16) is not a succedaneous tooth because it has no predecessor. The deciduous teeth are all still in position and functioning when the first molar takes its place.

• Because the development of the bones of the face is downward and forward, sufficient space has been created normally at age 6 years for the accommodation of this tooth.