complementary strand. noun, Biochemistry. 1. either of the two chains that make up a double helix of DNA, with corresponding positions on the two chains being composed of a pair of complementary bases. 2. a section of one nucleic acid chain that is bonded to another by a sequence of base pairs.
The teething process. Most babies start teething at around six months. However, all babies are different and the timing of teething varies. Some babies are born with their first teeth. Others start teething before they are four months old, and some after 12 months. Early teething should not cause a child any problems, unless it affects their feeding. A rough guide to the different stages of teething is:
Teething refers to the process of new teeth rising or erupting through the gums. 1  Teething can begin in infants as young as 2 months of age, even though the first tooth usually does not appear until about 6 months of age. Some dentists have noted a family pattern of early, average, or late teethers. Children who have not gotten the first tooth by 18 months should be evaluated by the child's doctor. Usually, the first tooth to erupt is one of the lower, central incisors. Some children will have a pattern of serial eruption of their teeth. Others will have multiple dental eruptions at the same time.