<Table> <Tr> <Th> Time period </Th> <Th> Bones affected </Th> </Tr> <Tr> <Td> Third month of fetal development </Td> <Td> Ossification in long bones beginning </Td> </Tr> <Tr> <Td> Fourth month </Td> <Td> Most primary ossification centers have appeared in the diaphyses of bone . </Td> </Tr> <Tr> <Td> Birth to 5 years </Td> <Td> Secondary ossification centers appear in the epiphyses </Td> </Tr> <Tr> <Td> 5 years to 12 years in females , 5 to 14 years in males </Td> <Td> Ossification is spreading rapidly from the ossification centers and various bones are becoming ossified </Td> </Tr> <Tr> <Td> 17 to 20 years </Td> <Td> Bone of upper limbs and scapulae becoming completely ossified </Td> </Tr> <Tr> <Td> 18 to 23 years </Td> <Td> Bone of the lower limbs and os coxae become completely ossified </Td> </Tr> <Tr> <Td> 23 to 25 years </Td> <Td> Bone of the sternum , clavicles , and vertebrae become completely ossified </Td> </Tr> <Tr> <Td> By 25 years </Td> <Td> Nearly all bones are completely ossified </Td> </Tr> </Table>
<Table> <Tr> <Th> Time period </Th> <Th> Bones affected </Th> </Tr> <Tr> <Td> Third month of fetal development </Td> <Td> Ossification in long bones beginning </Td> </Tr> <Tr> <Td> Fourth month </Td> <Td> Most primary ossification centers have appeared in the diaphyses of bone . </Td> </Tr> <Tr> <Td> Birth to 5 years </Td> <Td> Secondary ossification centers appear in the epiphyses </Td> </Tr> <Tr> <Td> 5 years to 12 years in females , 5 to 14 years in males </Td> <Td> Ossification is spreading rapidly from the ossification centers and various bones are becoming ossified </Td> </Tr> <Tr> <Td> 17 to 20 years </Td> <Td> Bone of upper limbs and scapulae becoming completely ossified </Td> </Tr> <Tr> <Td> 18 to 23 years </Td> <Td> Bone of the lower limbs and os coxae become completely ossified </Td> </Tr> <Tr> <Td> 23 to 25 years </Td> <Td> Bone of the sternum , clavicles , and vertebrae become completely ossified </Td> </Tr> <Tr> <Td> By 25 years </Td> <Td> Nearly all bones are completely ossified </Td> </Tr> </Table>
when do the bones of the sternum become completely ossified
when do the bones of the sternum become completely ossified
23 to 25 years
23 to 25 years