The common clinical causes of late teething in babies include genetic factors, malnutrition, hypothyroidism and so on. 1. Genetic factors: the time of teething of babies is affected by genetic factors. Some children are congenitally late teething. 2. Malnutrition: Babies do not get enough nutrients from their daily diet, such as calcium, phosphorus, protein, vitamin D, etc., which will affect the normal eruption of teeth. 3. Hypothyroidism: Low levels of thyroid hormones in hypothyroid patients may lead to delayed growth and development, which can also lead to late teething. Late teething can also be caused by other reasons, it is recommended to consult a doctor in time to clarify the cause of treatment.