If your baby hasn’t teethed in seven months, it may be caused by congenital lack of tooth germ tissue, genetic factors, calcium deficiency and so on. 1. Congenital lack of tooth germ tissue: Newborns with congenital lack of tooth germ tissue will not be able to teethe, but this is rare. 2. Genetic factors: Although most babies will start to erupt new teeth around 4~6 months, there may be some babies who will have early or delayed teething due to genetic factors and other factors. 3. Calcium deficiency: If a baby is deficient in calcium for various reasons, it will affect the growth of teeth, thus delaying teething. If your baby is still not teething at seven months, parents should take your baby to the hospital for a health checkup to detect the problem and deal with it at any time.