How ugly are the new incisors? Parents often have the feeling that their children are starting to get new teeth, but why are the new teeth ugly? In fact, your children are going through their “ugly duckling” period. The “ugly duckling” period refers to the time when children’s permanent teeth start to be replaced and their newly erupted front teeth are crooked and unattractive. A prominent feature of this period is that there is often a large gap between the two front incisors. This causes the child’s face to look particularly uncoordinated when speaking, especially when smiling. Parents are often concerned about whether their child needs orthodontic treatment. In fact, most parents do not have to worry too much about this. When the upper front teeth of children first erupt, the two crowns will grow like a figure of eight, which is a normal transitional state. That is because the roots of the upper front incisors are being squeezed by the germ on the side and there is a skew and gap. Therefore, after the teeth on both sides of the front incisors, i.e., lateral incisors and cuspids (also known as tigers) erupt, the gaps in between can slowly disappear on their own, and the skewed teeth will adjust and line up. In addition, there are some special conditions that can cause large gaps between incisors, which need to be treated: children with bad habits, such as biting fingers, pens, etc., or sleeping with their mouths open at night due to nasopharyngeal disorders, can cause the incisors to protrude and the gaps between teeth to slowly become larger. Some children may have multiple teeth. Multiple dentition refers to the development of teeth with a larger than normal number of embryos. Most of these teeth are located between the upper front incisors and can interfere with the normal closure of the gap between the two incisors. If parents find a gap between the two upper incisors during tooth replacement, they should not confuse the normal physiological phenomenon with the pathological condition, especially not to put rubber bands on the gap teeth by themselves to cause damage to the teeth and gums. Parents are advised to bring their children to the hospital for examination in a timely manner so that a professional doctor can determine whether the gap between the incisors is physiological or pathological before further treatment.