Final answer:
A dentist usually will not begin treatment for thumb sucking until a child is 5 years old. Children often outgrow the habit naturally, and treatment is often delayed unless the habit is affecting the child's dental health.
Step-by-step explanation:
Usually, dentists will not begin some form of treatment for thumb sucking until the age of 5. Thumb sucking is a common behavior in young children and is a normal part of early childhood development. However, in most cases, it is beneficial to wait until the child is a bit older to address this habit unless it is causing immediate dental problems. This is because children typically grow out of the habit on their own as they mature and develop.
It is noted that by around age 6, children begin losing their deciduous teeth, which is an important milestone in dental development. As they reach this age, they start to develop their permanent teeth, which makes it an appropriate time to address any habits or issues that might affect the alignment of their new teeth. Nevertheless, treatment for thumb sucking typically starts a year before this transition, around age 5, to prevent any potential impact on incoming permanent teeth.