Congenital and developmental birth defects of the mouth include cleft lips, cleft palate, hypodontia or missing teeth, hyperdontia or extra teeth, anomalies in the tooth structure, enamel defects, dentin defects, etc.

Cleft lips and cleft palates occur when the tissues of the lips and palates do not grow properly in the early stages of pregnancy. Environmental factors such as drugs and certain illnesses during pregnancy can cause a cleft lip and palate. Hypodontia and hyperdontia have genetic causes. Discolored and stained teeth can result from genetic factors and prescription tetracyclin drugs. Vitamin deficiencies can also cause congenital structural defects of the teeth.